MedWorm.com provides a medical RSS filtering service. Over 6000 RSS medical sources are combined and output via different filters. This feed contains the latest items from the 'Dental Materials' source. Fri, 19 Mar 2010 18:04:53 +0100 http://www.medworm.com/index.php?rid=3302233&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564110000023%2Fabstract%3Frss%3Dyes Abstract: Objective: To investigate the effect of three different primers on shear and peel bond strengths between three maxillofacial silicone elastomers and an acrylic resin after 360h of accelerated daylight-aging.Materials and methods: Peel and shear-bond strengths of three maxillofacial silicone elastomers (TechSil S25, Cosmesil M511, Cosmesil Z004) to acrylic denture resin bases using three adhesive primers (611, A304, A330-G) were assessed at baseline and after 360h of accelerated artificial light-aging. Data were collected and statistically analyzed by two-way ANOVA, one-way ANOVA, and Bonferroni post hoc tests (α=0.05). Independent t-test was used to investigate the effect of light-aging on bond strengths (α=0.05). Modes of failure were visually analyzed and categorized as adhes... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3302233 Wed, 24 Feb 2010 17:29:13 +0100 3302233 http://www.medworm.com/index.php?rid=3302232&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109005132%2Fabstract%3Frss%3Dyes Abstract: Dentin bonding performed with hydrophobic resins using ethanol-wet bonding should be less susceptible to degradation but this hypothesis has never been validated.Objectives: This in vitro study evaluated stability of resin–dentin bonds created with an experimental three-step BisGMA/TEGDMA hydrophobic adhesive or a three-step hydrophilic adhesive after one year of accelerated aging in artificial saliva.Methods: Flat surfaces in mid-coronal dentin were obtained from 45 sound human molars and randomly divided into three groups (n=15): an experimental three-step BisGMA/TEGDMA hydrophobic adhesive applied to ethanol (ethanol-wet bonding—GI) or water-saturated dentin (water-wet bonding—GII) and Adper Scotchbond Multi-Purpose [MP—GIII] applied, according to manufacturer instruct... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3302232 Wed, 24 Feb 2010 17:29:13 +0100 3302232 http://www.medworm.com/index.php?rid=3302231&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109005120%2Fabstract%3Frss%3Dyes Abstract: Objective: To compare resin–dentin bond strengths and the micropermeability of hydrophobic vs. hydrophilic resins bonded to acid-etched or EDTA-treated dentin, using the ethanol wet-bonding technique.Methods: Flat dentin surfaces from extracted human third molars were conditioned before bonding with: 37% H3PO4 (15s) or 0.1M EDTA (60s). Five experimental resin blends of different hydrophilicities and one commercial adhesive (SBMP: Scotchbond Multi-Purpose) were applied to ethanol wet-dentin (1min) and light-cured (20s). The solvated resins were used as primers (50% ethanol/50% comonomers) and their respective neat resins were used as the adhesive. The resin-bonded teeth were stored in distilled water (24h) and sectioned in beams for microtensile bond strength testing. Modes of f... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3302231 Wed, 24 Feb 2010 17:29:13 +0100 3302231 http://www.medworm.com/index.php?rid=3302230&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109005119%2Fabstract%3Frss%3Dyes Abstract: Objectives: The purpose of this study was to evaluate the relationship between changes in the modulus of elasticity and ultimate tensile strength of one-step self-etch adhesives, and their degree of water sorption.Methods: Five one-step self-etch adhesives, Xeno IV (Dentsply Caulk), G Bond (GC Corp.), Clearfil S3 Bond (Kuraray Medical Inc.), Bond Force (Tokuyama Dental Corp.), and One-Up Bond F Plus (Tokuyama Dental Corp.) were used. Ten dumbelled-shaped polymers of each adhesive were used to obtain the modulus of elasticity by the three-point flexural bending test and the ultimate tensile strength by microtensile testing. The modulus of elasticity and the ultimate tensile strength were measured in both dry and wet conditions before/after immersion in water for 24h. Water sorptio... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3302230 Wed, 24 Feb 2010 17:29:12 +0100 3302230 http://www.medworm.com/index.php?rid=3302229&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109005107%2Fabstract%3Frss%3Dyes Abstract: Purpose: To evaluate important material properties of six experimental resin-based restorative materials (EXP) with systematically modified resin matrices using conventional and alternative monomers in comparison with an experimental standard (ST).Materials and methods Commercially available monomers were selected according to their molecular weight, functionality, viscosity, and polymerization shrinkage. ST, 71wt% filler, matrix UDMA/Bis-GMA/TTEGDMA and six EXPs with modified organic matrices but the same filler content were manufactured. Flexural strength, flexural modulus, water sorption, solubility and polymerization shrinkage of all EXPs were measured and compared with the results of ST.Results: ANOVA (p (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3302229 Wed, 24 Feb 2010 17:29:12 +0100 3302229 http://www.medworm.com/index.php?rid=3302228&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109005090%2Fabstract%3Frss%3Dyes This study evaluated the effect of a new experimental primer, a mixture of organophosphate and carboxylic acid monomers, on the zirconia-to-resin shear bond strength (SBS).Methods: Forty Y-TZP blocks (15×4×2mm) were embedded in an acrylic resin base, polished, Al2O3-sandblasted and randomly divided into eight groups. Three different resin-based luting agents (BisCem, Duo-Link, Panavia F) were used to build 2.4mm-diameter cylinders (n=15) onto the zirconia surface with and without the new experimental zirconia primer. The new primer was also tested with Z100 restorative composite resin cylinders. In addition, Panavia was used with its own primer (Clearfil Ceramic Primer). SBS testing was carried out after 24h of storage in water. Scanning electron microscopy (SEM) was used to evaluate the... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3302228 Wed, 24 Feb 2010 17:29:12 +0100 3302228 http://www.medworm.com/index.php?rid=3302227&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109005089%2Fabstract%3Frss%3Dyes Abstract: Objectives: To distinguish the physical properties of a new silorane-based restorative material in comparison to five methacrylate-based restorative materials – a compomer, giomer, nanocomposite, hybrid and micro-hybrid.Methods: The following properties were examined per restorative material: compressive strength, diametral tensile strength, flexural strength/modulus, fracture toughness, microhardness, and polymerization shrinkage. The mean and standard deviation were determined per group. A one-way ANOVA/Tukey was performed per property (α=0.05).Results: Significant differences were found between groups per property (p (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3302227 Wed, 24 Feb 2010 17:29:12 +0100 3302227 http://www.medworm.com/index.php?rid=3302226&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109005053%2Fabstract%3Frss%3Dyes Abstract: Objectives: Since stylus profilometry applies a force on the sample surface, it is logical to hypothesize that the profilometer penetrates the surface of the enamel softened by acid solutions. The aims of the present study were, therefore, to test the hypothesis that surface profilometry measurements of eroded enamel alter the surface of the enamel, to quantify the potential effect of the surface alteration (scratches) on the measured values of enamel erosion by atomic force microscopy and to compare the values of enamel loss caused by erosion as measured by profilometry and non-contact confocal laser scanning microscopy (CLSM).Methods: Enamel samples, cut from unerupted human third molars were treated with Volvic Mineral Water and citric acid solutions of different pH values. Th... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3302226 Wed, 24 Feb 2010 17:29:12 +0100 3302226 http://www.medworm.com/index.php?rid=3302225&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004990%2Fabstract%3Frss%3Dyes This study evaluated the role of endogenous dentin MMPs in auto-degradation of collagen fibrils within adhesive-bonded interfaces. The null hypotheses tested were that adhesive blends or chlorhexidine digluconate (CHX) application does not modify dentin MMPs activity and that CHX used as therapeutic primer does not improve the stability of adhesive interfaces over time.Methods: Zymograms of protein extracts from human dentin powder incubated with Adper Scotchbond 1XT (SB1XT) on untreated or 0.2–2% CHX-treated dentin were obtained to assay dentin MMPs activity. Microtensile bond strength and interfacial nanoleakage expression of SB1XT bonded interfaces (with or without CHX pre-treatment for 30s on the etched surface) were analyzed immediately and after 2 years of storage in artificial sal... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3302225 Wed, 24 Feb 2010 17:29:12 +0100 3302225 http://www.medworm.com/index.php?rid=3302224&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004989%2Fabstract%3Frss%3Dyes Abstract: Objectives: (1) To evaluate the changes in surface roughness and gloss after simulated toothbrushing of 9 composite materials and 2 ceramic materials in relation to brushing time and load in vitro; (2) to assess the relationship between surface gloss and surface roughness.Methods: Eight flat specimens of composite materials (microfilled: Adoro, Filtek Supreme, Heliomolar; microhybrid: Four Seasons, Tetric EvoCeram; hybrid: Compoglass F, Targis, Tetric Ceram; macrohybrid: Grandio), two ceramic materials (IPS d.SIGN and IPS Empress polished) were fabricated according to the manufacturer's instructions and optimally polished with up to 4000 grit SiC. The specimens were subjected to a toothbrushing (TB) simulation device (Willytec) with rotating movements, toothpaste slurry and at th... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3302224 Wed, 24 Feb 2010 17:29:12 +0100 3302224 http://www.medworm.com/index.php?rid=3302223&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004242%2Fabstract%3Frss%3Dyes Abstract: Objectives: The aim of the study was to characterize the chemical composition, microstructure and roughness of two commercially available zirconia dental implants (WhiteSky and Zit-Z).Methods: The chemical composition of the cervical collar and threaded root parts of the implants (n=2) were studied by XPS and HV-EDX. LV-SEM was used for morphological assessment, Raman microanalysis for microstructural characterization and optical profilometry for surface roughness measurements. XRD, HV-EDX and Raman microanalysis of bulk regions (longitudinal sections) were used as reference.Results: XPS showed the presence of C, O, Zr and Y (collar) plus Al (root) at implant surfaces. More C (10–26at%) and a lower Al/Zr ratio were found in WhiteSky (1.05 vs 1.26 in Zit-Z). Zr, Y and Al were de... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3302223 Wed, 24 Feb 2010 17:29:11 +0100 3302223 http://www.medworm.com/index.php?rid=3302222&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004230%2Fabstract%3Frss%3Dyes Abstract: Objectives: The aim of this study was to compare the curing reaction of five experimental adhesive blends containing different photo-initiating systems. The hypothesis tested was that degree of conversion (DC) of resin blends is affected by resin type, solvent content and photo-initiating system.Methods: The experimental methacrylate resin blends were ranked from hydrophobic (R2) to hydrophilic (R3 and R4) and tested as neat, or solvated with 10% or 20% ethanol, or 10% ethanol and 10% water. Three different photo-initiators were used: IS-1=0.25% CQ (camphorquinone)+1% EDMAB (ethyl 4-dimethylaminobenzoate); IS-2=1.25% TPO (diphenyl(2,4,6-trimethylbenzoyl)-phosphine oxide); IS-3=0.25% CQ+0.50% EDMAB+0.50% TPO. DC of resin blends was measured with a differential scanning calorimeter... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3302222 Wed, 24 Feb 2010 17:29:11 +0100 3302222 http://www.medworm.com/index.php?rid=3302221&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004229%2Fabstract%3Frss%3Dyes Abstract: Objective: There is a great demand for dental implant surfaces to accelerate the process of peri-implant bone generation to reduce its healing time and enable early loading. To this end, an inverse correlation between the proliferation and functional maturation (differentiation) in osteoblasts presents a challenge for the rapid generation of greater amounts of bone. For instance, osteoblasts exhibit faster differentiation but slower proliferation on micro-roughened titanium surfaces. Using a unique micro-nano-hierarchical topography of TiO2 that mimics biomineralized matrices, this study demonstrates that this challenge can be overcome without the use of biological agents.Methods: Titanium disks of grade 2 commercially pure titanium were prepared by machining (smooth surface). To... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3302221 Wed, 24 Feb 2010 17:29:11 +0100 3302221 http://www.medworm.com/index.php?rid=3302220&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564110000394%2Fabstract%3Frss%3Dyes (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3302220 Wed, 24 Feb 2010 17:29:11 +0100 3302220 http://www.medworm.com/index.php?rid=3227620&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004217%2Fabstract%3Frss%3Dyes Abstract: Objectives: The aim of this study was to evaluate the effectiveness of liner and base materials to reduce the stress resulting from polymerization shrinkage. The null hypothesis tested was that the presence of low-viscosity liner and base materials under the composite resin restoration reduces the polymerization shrinkage stress.Methods: A quasi-three-dimensional photoelastic model of a second premolar with a class I preparation was restored using four experimental groups (n=7): RC, resin composite (Filtek Z250); FLRC, flowable liner (Filtek Flow)+resin composite restoration; VLRC, resin-modified glass-ionomer liner+resin composite restoration; and VBRC, resin-modified glass-ionomer base+resin composite restoration. The maximum shear stresses (τmax) were calculated along the adh... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3227620 Mon, 01 Feb 2010 18:00:03 +0100 3227620 http://www.medworm.com/index.php?rid=3227619&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS010956410900339X%2Fabstract%3Frss%3Dyes Abstract: Objectives: The aim of this study was the interfacial characterization and the determination of bond strength of commercially available low fusing dental porcelain for Ti.Methods: Eight materials were included in this study: Duceratin, Duceratin Plus, Initial Ti, Ti-22, TiKrom, TitanKeramik, Triceram (powder) and Triceram (paste). Eight ISO 9693 bond characterization specimens from each porcelain were prepared according to manufacturers’ instructions. One specimen from each group was embedded in acrylic resin and after metallographic preparation was studied under an SEM. Interfacial characterization was carried out with Backscattered Electron Imaging and X-ray EDS analysis operating in line scan mode. Metal–ceramic specimens were tested in three point bending at a crosshead s... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3227619 Mon, 01 Feb 2010 18:00:03 +0100 3227619 http://www.medworm.com/index.php?rid=3227618&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109003388%2Fabstract%3Frss%3Dyes This study evaluated the relationship between microtensile bond strength (μTBS) and occurrence of submicron hiatus formations at the resin–dentin interface using the same specimens.Methods: Resin–dentin bonded micro-specimens (sticks with a size of 300μm×300μm×8mm) were prepared using one of two material combinations (group I: Syntac Classic/Tetric Ceram Cavifil: n=51 group II: Prime & Bond NT/Tetric Ceram Cavifil: n=56). After labeling the primer component with a tiny amount of rhodamine-B-isothiocyanate, submicron hiatus formations were imaged nondestructively using a confocal laser scanning microscope (CLSM). Subsequently specimens were subjected to a μTBS test.Results: For the influence of submicron hiatus formations on μTBS with the Syntac Classic group, the nonparametric S... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3227618 Mon, 01 Feb 2010 18:00:03 +0100 3227618 http://www.medworm.com/index.php?rid=3227617&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109003376%2Fabstract%3Frss%3Dyes Abstract: Objectives: Nickel chromium is widely used as a restorative material in dentistry but its biocompatibility is of concern as there are reports of patients suffering adverse effects caused by exposure to nickel-based restorations. The aim of this work was to quantify the amount of nickel released into solution from commercially available nickel-based alloys with varying compositions and to identify the potential use of thin films in further understanding the role of chromium in reducing nickel release.Methods: Six commercially available nickel-based alloys were cast using the lost wax technique. Nickel chromium thin films were deposited onto silicon substrates by ion beam assisted physical vapor deposition. Both types of alloys were immersed into solution representative of saliva a... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3227617 Mon, 01 Feb 2010 18:00:03 +0100 3227617 http://www.medworm.com/index.php?rid=3227616&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109003364%2Fabstract%3Frss%3Dyes Abstract: Objective: The aim of this study was to elucidate whether marginal performance (in terms of % of continuous margins) can, or not, be predicted from μTBS values. A relationship was attempted between μTBS and % of continuous margins (% CM) before and after loading of class V restorations made with five restorative systems from both etch & rinse and self-etch approach.Methods: Resin–dentin slabs and as well as class V cavities with cervical margins in dentin were prepared and restored using five adhesive systems (Scotchbond Multipurpose Plus (SMPP), James 2, Experimental Bond, Xeno III and iBond) with their corresponding restorative composites. Bond strength and percentages of continuous margins were calculated before and after thermal and mechanical loading. Statistical correla... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3227616 Mon, 01 Feb 2010 18:00:03 +0100 3227616 http://www.medworm.com/index.php?rid=3227615&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109003339%2Fabstract%3Frss%3Dyes Abstract: Objectives: The dental resin monomer triethylene glycol dimethacrylate (TEGDMA) caused a cell cycle arrest in response to DNA damage. However, the underlying mechanisms are unclear. Therefore, the influence of TEGDMA on the cell cycle was analyzed in comparison with the chemotherapeutic agents adriamycin and mitomycin C (MMC), which arrest the cell cycle through different mechanisms.Methods: RAW264.7 mouse macrophages were exposed to TEGDMA, adriamycin, or MMC, and flow cytometry (FACS) was used for cell cycle analyses. In addition, the number of surviving cells was determined by a crystal violet assay, and viability in treated cultures was determined by FACS after staining of cells with trypan blue. Morphological changes in cells were interpreted using forward and side scatter (... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3227615 Mon, 01 Feb 2010 18:00:03 +0100 3227615 http://www.medworm.com/index.php?rid=3227614&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109003315%2Fabstract%3Frss%3Dyes Abstract: Objectives: The aim of this study was to develop a method to experimentally determine and visualize the direction and amount of polymerization shrinkage.Methods: We modified a composite to include 1.5wt% traceable glass beads. A cylindrical cavity (6mm diameter, 3mm height) was restored with this traceable composite, with and without dentin adhesive, and digitized with high-resolution micro-computed tomography (μCT). Image segmentation was performed to extract the glass beads from the acquired 3D μCT images (uncured and cured). Afterwards, each glass bead was subjected to local rigid registration. The resulting displacement vectors were used to examine and calculate the changes.Results: In unbonded restorations, the displacement vectors were oriented inwards to the center of ma... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3227614 Mon, 01 Feb 2010 18:00:02 +0100 3227614 http://www.medworm.com/index.php?rid=3227613&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109003212%2Fabstract%3Frss%3Dyes Abstract: Objectives: Polymerization shrinkage of a composite in a high configuration-factor (C-factor) cavity leads to polymerization shrinkage stress. In the prevention of high polymerization shrinkage stress, a low-shrinking silorane composite (Filtek Silorane, FS, 3M ESPE) was recently marketed. Therefore, we investigated the effect of C-factor (flat surface vs. class-I cavity) and different composite application protocols on the bonding effectiveness of a low-shrinking composite to human dentin.Methods: A low-shrinking silorane-based composite (FS) and a conventional methacrylate-based composite (Filtek Z100, 3M-ESPE) were bonded to standardized occlusal class-I cavities (4mm×4mm×2.5mm) and to flat mid-coronal dentin surfaces using the two-step self-etch adhesive ‘Silorane System ... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3227613 Mon, 01 Feb 2010 18:00:02 +0100 3227613 http://www.medworm.com/index.php?rid=3227612&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109003200%2Fabstract%3Frss%3Dyes Abstract: Objective: The purpose of this study was to examine the fracture toughness (KIC) of three direct dental composites and one indirect dental composite subject to cyclic loading.Methods: The composites were a micro-filled (Micronew, Bisco INC., Schaumburg, IL, USA), a hybrid (Renew, Bisco INC.), a nano-filled composite (Filtek Supreme Plus, 3M ESPE, St. Paul, MN, USA) and an indirect dental composite (BelleGlass HP, SDS-Kerr, Orange, CA, USA). Rectangular bar specimens (3mm×3mm×25mm) were fabricated, notched, aged (5 months) and cyclic loaded in four different environments, air, water, artificial saliva, and a 50/50 by volume mixture of ethanol and water. Specimens were cyclic loaded for 1, 1000, 10,000, and 100,000 cycles.Results: A 3-way ANOVA (non-aged and aged group, four agin... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3227612 Mon, 01 Feb 2010 18:00:02 +0100 3227612 http://www.medworm.com/index.php?rid=3227611&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109003327%2Fabstract%3Frss%3Dyes Abstract: Objective: The purpose of this review was to assess the influencing factors which affect laboratory tests that evaluate the effectiveness of luting agents on the retention of crowns in prepared dentin and – based on the results of the review – to propose a reasonable experimental setup.Materials and methods: The database MEDLINE was systematically searched for laboratory methods that evaluated the effectiveness of luting agents by pulling off crowns from prepared extracted teeth.Results: Eighteen studies were included into the systematic review. The studies varied largely with regard to tooth type (molars, premolars), number of specimens (9–25), stump height (3–6mm), convergence angle (4.8–33°), standardization and measurement of preparation surface, seating force (25�... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3227611 Mon, 01 Feb 2010 18:00:02 +0100 3227611 http://www.medworm.com/index.php?rid=3227610&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564110000096%2Fabstract%3Frss%3Dyes (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3227610 Mon, 01 Feb 2010 18:00:02 +0100 3227610 http://www.medworm.com/index.php?rid=3220425&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109003194%2Fabstract%3Frss%3Dyes Abstract: Objectives: Maxillofacial silicone elastomers are used to replace facial parts lost through disease or trauma. However, these materials do not possess ideal properties. The purpose of this study was to investigate the mechanical properties of recently and previously introduced maxillofacial silicone elastomers and their bond strength to acrylic resin substrate.Materials and methods: Specimens of three maxillofacial silicone elastomers (TechSil S25, Cosmesil M511, and Cosmesil Z004) were prepared according to manufacturers’ instructions. Tear and tensile strengths, elongation percentage, modulus of elasticity and hardness were evaluated for each material. Shear bond strengths of these silicone elastomers to primed acrylic resin surfaces were evaluated. Data was analyzed with 1-w... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220425 Fri, 29 Jan 2010 16:36:21 +0100 3220425 http://www.medworm.com/index.php?rid=3220424&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109003182%2Fabstract%3Frss%3Dyes Abstract: Objectives: The small volume of human dentin available for sample preparation and the local variations in its microstructure present a real challenge in the determination of their mechanical properties. The main purpose of the present study was to develop a new procedure for the preparation and mechanical testing of small-scale specimens of biomaterials such as dentin, so as to probe local mechanical properties as a function of microstructure.Methods: Ultra short laser pulses were used to mill a block of dentin into an array of 16μm size dentin pillars. These could then be individually tested in compression with an instrumented nanoindenter fitted with a 30μm wide flat punch.Results: The laser-based pillar preparation procedure proved effective and reliable. Data was produced f... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220424 Fri, 29 Jan 2010 16:36:21 +0100 3220424 http://www.medworm.com/index.php?rid=3220423&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109003170%2Fabstract%3Frss%3Dyes Abstract: Objective: One of the limitations of resin cements and flowable dental composites is their poor mechanical properties such as low flexural strength and fracture resistance under body conditions. The present study was performed to enhance the mechanical properties of commercial acrylic cement (CMW®1) by introducing novel nanostructured titania tubes (n-TiO2 tubes) into the cement matrix, with the tubes acting as a reinforcing phase. The long term objective is to add these fillers as reinforcement to dental resin cements and flowable composites in combination with existing fillers.Methods: The surface of the n-TiO2 tubes was modified using a bi-functional monomer, methacrylic acid. The n-TiO2 tube content of the cement was varied from 0 to 2wt.%. The following cement properties we... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220423 Fri, 29 Jan 2010 16:36:21 +0100 3220423 http://www.medworm.com/index.php?rid=3220422&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109003169%2Fabstract%3Frss%3Dyes Abstract: Objective: The aim of this investigation was to determine the effect of an experimental liquid rubber (LR) toughening agent on fracture toughness, crosslink density and Barcol hardness of polymerized mixtures of 50/50wt% Bis-GMA and TEGDMA.Methods: An experimental LR, was added to a solution of Bis-GMA and TEGDMA containing 1wt% dimethylamino ethyl methacrylate and 0.5wt% camphoroquinone at concentrations 0–10%. The composites were polymerized by exposure to a visible light curing unit for 60s. Fracture toughness was determined according to ASTM. 399. Crosslink density was evaluated using a swell test in ethanol.Results: Mean fracture toughness values ranged from 0.39MPam1/2 for samples containing 6% to 1.24MPam1/2 for samples containing 8% LR. Fracture toughness of samples con... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220422 Fri, 29 Jan 2010 16:36:21 +0100 3220422 http://www.medworm.com/index.php?rid=3220421&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109003157%2Fabstract%3Frss%3Dyes Conclusion: Rational design of veneered structural ceramics must consider the complex geometry of the crown–tooth system and integrate the influence of both the main effects and interactions among design parameters. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220421 Fri, 29 Jan 2010 16:36:21 +0100 3220421 http://www.medworm.com/index.php?rid=3220420&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109003121%2Fabstract%3Frss%3Dyes Abstract: Objective: To investigate the effect of irradiance through choice of LED light-curing unit (LCU) and fiber-optic tip on the mechanical properties of methacrylate resin-based composites (RBCs).Methods: Rectangular bar-shaped specimens (25mm×2mm×2mm) of four RBCs, irradiated from one side for the manufacturer's recommended times with one of two LED LCUs, and with either 8 or 13mm tip diameter, were tested in three-point bend for flexural strength and modulus of elasticity; Vickers hardness was measured on top and bottom surfaces, on overlapped and non-overlapped irradiation sites. The effects and interactions of all factors were examined by analysis of variance.Results: While the materials tested differed significantly for all properties (P (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220420 Fri, 29 Jan 2010 16:36:20 +0100 3220420 http://www.medworm.com/index.php?rid=3220419&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109003108%2Fabstract%3Frss%3Dyes Conclusions: Weibull analysis has a strong theoretical basis and can be of particular value in dental applications, primarily because of test specimen size limitations and the use of different test configurations. Also endemic to dental materials, however, is increased difficulty in satisfying application requirements, such as confirming fracture origin type and diligence in obtaining quality strength data. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220419 Fri, 29 Jan 2010 16:36:20 +0100 3220419 http://www.medworm.com/index.php?rid=3220418&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109003091%2Fabstract%3Frss%3Dyes This study aims to validate a cavity shape optimization approach for improving the debonding resistance of dental restorations by carrying out fracture tests on restored model teeth with standard and optimized cavity designs.Method: The bio-mimetic stress-induced material transformation (SMT) optimization method was incorporated into the finite element (FE) program ABAQUS as a user material (UMAT) subroutine. The method uses stress minimization to optimize the cavity shape of a MOD restoration in an artificial premolar with special reference to the tooth–restoration interface under occlusal loads. The mechanical performance of the optimized design was first verified through FE analysis and then compared with that of the conventional design using fracture tests on model teeth.Results: The... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220418 Fri, 29 Jan 2010 16:36:20 +0100 3220418 http://www.medworm.com/index.php?rid=3220417&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS010956410900308X%2Fabstract%3Frss%3Dyes Abstract: Objectives: This investigation evaluated the flexural properties of two composite resins, and the influence of unidirectional glass fiber reinforcements, with and without pre-tensioning.Methods: Two composite resins (Q: Quixfil and A: Adoro) were used to fabricate 2mm×2mm×25mm beams (N=10), reinforced with two fiber bundles along the long axis of the beam and pre-tensioned under a load equivalent to 73.5% of its tensile strength (groups QPF and APF). In two other experimental groups, the bundles were similarly positioned but without pre-tension (groups QF and AF). Two more groups were included without fiber reinforcement (control groups Q and A). After 24h storage, specimens were subjected to a three-point flexural bending test to establish the flexural module, the deflection a... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220417 Fri, 29 Jan 2010 16:36:20 +0100 3220417 http://www.medworm.com/index.php?rid=3220416&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109003078%2Fabstract%3Frss%3Dyes The objective of this study was to test the null hypothesis that the interfacial toughness of each of two types of bonded core-veneer bilayer ceramics is not significantly different from the apparent fracture toughness of the control monolithic glass veneer.Methods: T-shaped short-bars of a lithia-disilicate glass–ceramic core (LC) and yttria-stabilized polycrystalline zirconia core ceramic (ZC) were prepared according to the manufacturer's recommendations. V-shaped notches were prepared by using 25-μm-thick palladium foil, leaving the chevron-notch area exposed, and the bars were veneered with a thermally compatible glass veneer (LC/GV and ZC/GV). Additionally, we also bonded the glass veneer to itself as a control group (GV/GV). Specimens were kept in distilled water for 30 days befor... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220416 Fri, 29 Jan 2010 16:36:20 +0100 3220416 http://www.medworm.com/index.php?rid=3220415&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004928%2Fabstract%3Frss%3Dyes Objectives: To evaluate the bond strength of conventional and self-adhesive resin cements to a yttrium-oxide-stabilized polycrystalline tetragonal zirconia ceramic (YTZP) considering 3 factors (cement in 4 levels [Panavia F2.0, Variolink II, Relyx U100, Maxcem]; surface treatment in 2 levels [cleaning with alcohol, silicatization+silanization=SS]; storage condition in 2 levels (test in 24h, aging]) (factorial 4×2×2=16 groups). (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220415 Fri, 29 Jan 2010 16:36:20 +0100 3220415 http://www.medworm.com/index.php?rid=3220414&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004916%2Fabstract%3Frss%3Dyes Objectives: The Rocatec system conditions the bonding surface by fusing a unique silica layer onto the surface. The purpose of this study is to determine the effect of Rocatec treatment on the bond strength of stainless steel brackets. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220414 Fri, 29 Jan 2010 16:36:20 +0100 3220414 http://www.medworm.com/index.php?rid=3220413&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004904%2Fabstract%3Frss%3Dyes In this study, curing process of three different kinds of resin-based luting cements were monitored utilizing dynamic small-amplitude oscillatory shear experiments. The purpose of this study was to investigate clinically relevant, quantitative methodology to characterize the working and setting times of luting cements. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220413 Fri, 29 Jan 2010 16:36:20 +0100 3220413 http://www.medworm.com/index.php?rid=3220412&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004898%2Fabstract%3Frss%3Dyes This study evaluated the shear bond strength of adhesive interfaces created with ResiCem (Shofu Inc., Kyoto, Japan) and zirconia or Cp Titanium. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220412 Fri, 29 Jan 2010 16:36:20 +0100 3220412 http://www.medworm.com/index.php?rid=3220411&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004886%2Fabstract%3Frss%3Dyes Objective: The overall goal of this research was to chemically modify the surface of zirconia dental ceramics with a SixOy seed layer to increase adhesive bonding with commercially available silanes and resin cements. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220411 Fri, 29 Jan 2010 16:36:20 +0100 3220411 http://www.medworm.com/index.php?rid=3220410&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004874%2Fabstract%3Frss%3Dyes Objectives: The free radical concentrations of resin materials do not only compromise the material polymerization properties but also may impact its overall biocompatibility due to higher concentrations of residual monomers. The aim of this study was to detect free radical concentrations of three new self-adhesive resin cements using electron spin resonance (ESR) spectroscopy. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220410 Fri, 29 Jan 2010 16:36:20 +0100 3220410 http://www.medworm.com/index.php?rid=3220409&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004862%2Fabstract%3Frss%3Dyes The objective of this study was to evaluate the effect of different particle deposition protocols on the biaxial flexural strength of a commercial zirconia after long term cyclic loading. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220409 Fri, 29 Jan 2010 16:36:20 +0100 3220409 http://www.medworm.com/index.php?rid=3220408&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004850%2Fabstract%3Frss%3Dyes This study evaluated hardness changes in a variety of commercial soft liner products during long-term water storage. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220408 Fri, 29 Jan 2010 16:36:20 +0100 3220408 http://www.medworm.com/index.php?rid=3220407&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004849%2Fabstract%3Frss%3Dyes Objectives: Proper cementation protocol is critical to the success of indirect restorations. Recommendation in materials and techniques however vary by manufacturer. The purpose of this study was to study the effects of silane on the cementation of indirect resin restorations. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220407 Fri, 29 Jan 2010 16:36:20 +0100 3220407 http://www.medworm.com/index.php?rid=3220406&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004837%2Fabstract%3Frss%3Dyes The objective of this study was to compare the Weibull parameters (characteristic strength, σ0, and Weibull modulus, m) and slow cracking growth (SCG) parameters (stress corrosion coefficient, n, and scalar parameter, σf0) obtained for a dental porcelain using two different specimen configurations. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220406 Fri, 29 Jan 2010 16:36:20 +0100 3220406 http://www.medworm.com/index.php?rid=3220405&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004825%2Fabstract%3Frss%3Dyes Objectives: To describe one method for the three-dimensional finite element modeling of dental implant by combining micro-CT technique and Mimics software. Materials and methods: One dental titanium implant with abutment (Bone Level RC, Straumann, Switzerland) was scanned using X-ray micro-CT scanner (Skyscan1172, Skyscan, Belgium) with exposure time of 1180ms and pixel size of 6.97μm. 3749 slice images were generated and then processed by an interactive medical image control system (Mimics X64 13.0, Materialise, Belgium). The 3D objects of implant and abutment were generated from different masks which were automatically extracted using thresholding and region growing tools based on the grey values. The MedCAD tool was used to create the cylindrical fixture and hemispherical cap in order... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220405 Fri, 29 Jan 2010 16:36:20 +0100 3220405 http://www.medworm.com/index.php?rid=3220404&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004813%2Fabstract%3Frss%3Dyes Objectives: The purpose of this study was to histomorphometrically compare a noncoated threaded zirconia implant vs. a noncoated threaded titanium implant in a rabbit model. The study tested the hypothesis that the bone-tissue response to noncoated zirconia implants was qualitatively and quantitatively similar to noncoated titanium implants. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220404 Fri, 29 Jan 2010 16:36:20 +0100 3220404 http://www.medworm.com/index.php?rid=3220403&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004801%2Fabstract%3Frss%3Dyes Objectives: Traditional HF etching and silane treatment is not effective for improving the bonding towards zirconia ceramics. The purpose of this study was to evaluate the bonding ability of current zirconia bonding agents. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220403 Fri, 29 Jan 2010 16:36:20 +0100 3220403 http://www.medworm.com/index.php?rid=3220402&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004795%2Fabstract%3Frss%3Dyes Objectives: Repeated exposure to cyclic temperatures can result in change of bond strength. The purpose of this study is to determine the difference in shear bond strengths between a standard 24-h test and a 4000×-thermo-cycle (TC) test for a range of resin cements and bonding substrates using a newly developed shear bond strength testing rig assembly. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220402 Fri, 29 Jan 2010 16:36:20 +0100 3220402 http://www.medworm.com/index.php?rid=3220401&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004783%2Fabstract%3Frss%3Dyes Objectives: To evaluate the strength degradation of five ceramics (yttria stabilized zirconia, YZ; alumina polycrystal, AL; glass-infiltrated alumina–zirconia, ICZ; and porcelains VM7 and VM9, all from Vita) after in vitro aging procedures. The null hypothesis is that these procedures cause strength degradation in all ceramics. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220401 Fri, 29 Jan 2010 16:36:19 +0100 3220401 http://www.medworm.com/index.php?rid=3220400&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004771%2Fabstract%3Frss%3Dyes Objectives: Self-adhesive cements represent a new approach in fiber post-cementation. Aim of this study was to investigate the effect of storage in artificial saliva on bond strength of fiber posts luted with three different self-adhesive cements. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220400 Fri, 29 Jan 2010 16:36:19 +0100 3220400 http://www.medworm.com/index.php?rid=3220399&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS010956410900476X%2Fabstract%3Frss%3Dyes Objectives: We have recently reported the processing and physico-chemical characterization of a yttria-tetragonal zirconia polycrystal (Y-TZP) ceramic produced via coprecipitation with mechanical properties comparable to commercially reinforced ceramic materials. The purpose of the present investigation was to study the bond durability between the experimental zirconia and a phosphate monomer resin cement after two surface conditioning methods. The hypothesis tested was that bond strength is influenced by both the surface conditioning methods and storage conditions. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220399 Fri, 29 Jan 2010 16:36:19 +0100 3220399 http://www.medworm.com/index.php?rid=3220398&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004758%2Fabstract%3Frss%3Dyes This study evaluated the effect of the Ti condition (as-received and re-cast) on the mechanical properties, microstructure and fractography. Materials and methods: Castings (n=6) with Ti in the as-received and once recast condition were made in a centrifugal casting machine using a high-purity argon gas. The ultimate tensile strength (UTS), proportional limit (PL) and elongation (EL) of the as-received specimens were evaluated in a universal testing machine at a crosshead speed of 1mm/min. The fractured specimens were polished down for Vicker's microhardness (VHN) measurement (100g/15s) from 25μm below the cast surface, then at 50, 100, 200 and 500μm. The microstructures of the alloys were also revealed. Scanning electron microscopy fractography (SEM) was undertaken for the fractured su... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220398 Fri, 29 Jan 2010 16:36:19 +0100 3220398 http://www.medworm.com/index.php?rid=3220397&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004746%2Fabstract%3Frss%3Dyes Veneer cracking on zirconia core dental material is presenting as a clinical concern. There is no standard method for calculating the magnitude of residual stress that causes these crack patterns. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220397 Fri, 29 Jan 2010 16:36:19 +0100 3220397 http://www.medworm.com/index.php?rid=3220396&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004734%2Fabstract%3Frss%3Dyes Objectives: The aim of this study was to evaluate, using finite element analysis, the risk of debonding at the post/resin cement interface and root fracture in teeth restored with a metallic cast post (MCP) or glass fiber post (GFP). The hypothesis was that GFP would present a lower risk of debonding and/or of root fracture. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220396 Fri, 29 Jan 2010 16:36:19 +0100 3220396 http://www.medworm.com/index.php?rid=3220395&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004722%2Fabstract%3Frss%3Dyes Objectives: The purpose of this study was to investigate the effect of wet bonding and colloidal platinum nanoparticles (CPN, Apt, LTD) on the dentin bond strength of one-step bonding systems under four different bonding strategy groups: control, wet, etch-wet, etch-CPN-wet. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220395 Fri, 29 Jan 2010 16:36:19 +0100 3220395 http://www.medworm.com/index.php?rid=3220394&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004710%2Fabstract%3Frss%3Dyes Objectives: The aim of the study was to evaluate the influence of different levels of nanoparticles, dispersed in an commercial, unfilled adhesive, on the adhesive strength to dentin. The compounding of nanoparticles in either the primer or in the adhesive was observed as well as the distribution of the particles in the hybrid and adhesive layer. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220394 Fri, 29 Jan 2010 16:36:19 +0100 3220394 http://www.medworm.com/index.php?rid=3220393&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004709%2Fabstract%3Frss%3Dyes Matrix metalloproteinases (MMPs) bound to dentin have been thought to contribute to the progressive degradation of collagen fibrils in hybrid layers. Inhibition of host-derived MMPs may slow the degradation over time. Chlorhexidine (CHX) has been shown to have an anti-MMP activity and contains two cationic quaternary ammonium groups which seems to be responsible for this activity. However, CHX is water soluble which might compromise the long term effect. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220393 Fri, 29 Jan 2010 16:36:19 +0100 3220393 http://www.medworm.com/index.php?rid=3220392&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004692%2Fabstract%3Frss%3Dyes Objectives: To evaluate the tensile bond strength (TBS) of resin cements to bovine dentin resin-coated with all-in-one adhesive systems. Materials and methods: Each of the dual-cure resin cements; Link Max1, Clearfil Esthetic Cement2, Bistite II3 and Chemiace II4 were used to bond indirect resin disks to bovine dentin not coated with resin (control) or coated by single-application or by dual-application of an adhesive system from the same manufacturer; G-Bond1, Clearfil Tri-S Bond2, Tokuyama Bond Force3 and Hybrid-Coat4, respectively (n=10). After 24-h water storage, TBSs were measured at a crosshead speed of 2mm/min. The results were statistically analyzed by ANOVA and Bonfferroni's correction (p (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220392 Fri, 29 Jan 2010 16:36:19 +0100 3220392 http://www.medworm.com/index.php?rid=3220391&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004680%2Fabstract%3Frss%3Dyes This study investigated the bonding efficacy of Adper™ Easy Bond (EB, 3M ESPE), a 7th generation adhesive, when used in total-etch (5th generation) mode on either moist (EB-TE-moist) or dry (EB-TE-dry) superficial bovine dentin. The moist or dry condition of the tooth is after etching. The dry condition represents a product misuse scenario. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220391 Fri, 29 Jan 2010 16:36:19 +0100 3220391 http://www.medworm.com/index.php?rid=3220390&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004679%2Fabstract%3Frss%3Dyes This study was performed to investigate the compatibility between 4 dentin adhesives and 4 resin luting cements by means of uTBS test and SEM analysis for dentin–resin interface. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220390 Fri, 29 Jan 2010 16:36:19 +0100 3220390 http://www.medworm.com/index.php?rid=3220389&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004667%2Fabstract%3Frss%3Dyes Objectives: The aim of this study was to evaluate the microtensile bond strength of some current adhesive systems on root surface dentin after 24h of storage in distilled water. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220389 Fri, 29 Jan 2010 16:36:19 +0100 3220389 http://www.medworm.com/index.php?rid=3220388&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004655%2Fabstract%3Frss%3Dyes This study investigated the effects of various human saliva contamination and decontamination protocols on the shear bond strengths (SBS) of three adhesives on bovine superficial dentin. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220388 Fri, 29 Jan 2010 16:36:19 +0100 3220388 http://www.medworm.com/index.php?rid=3220387&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004643%2Fabstract%3Frss%3Dyes Objectives: To evaluate the fatigue resistance of adhesives bonded to dentin, in comparison to their micro-tensile bond strength (μTBS). Materials and methods: The bonding effectiveness of three adhesives (3-step etch-and-rinse adhesive or 3-E&RA OptiBond FL, 2-step self-etch adhesive or 2-SEA Clearfil SE, and 1-step self-etch adhesive or 1-SEA G-Bond) was measured by means of a micro-tensile fatigue resistance (μTFR) and μTBS protocol. Preparation and test set-up of the micro-specimens for both μTFR and μTBS were identical. In fatigue, specimens were tested in a wide range of selected loads at 2Hz and at 10Hz until failure or until 104 cycles were reached. At 2Hz, the μTFR was measured after 1 week and 3 months of water storage. The μTFR was determined (in MPa) using a logistic re... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220387 Fri, 29 Jan 2010 16:36:19 +0100 3220387 http://www.medworm.com/index.php?rid=3220386&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004631%2Fabstract%3Frss%3Dyes In this study the addition of polymerization promoters to experimental self-etching primers on the bond stability of two-step adhesives to dentin was investigated. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220386 Fri, 29 Jan 2010 16:36:19 +0100 3220386 http://www.medworm.com/index.php?rid=3220385&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS010956410900462X%2Fabstract%3Frss%3Dyes The objective of this paper was to study the role of the dual curing mechanism of RMGI liners on bond formation. Spectroscopic studies, rate of modulus build-up and stress development were investigated. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220385 Fri, 29 Jan 2010 16:36:19 +0100 3220385 http://www.medworm.com/index.php?rid=3220384&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004618%2Fabstract%3Frss%3Dyes Objectives: Degradation of hybrid layers (HL) within resin-infiltrated dentin has shown to result from multiple degradation factors, including the collagenolytic activity of specific matrix metalloproteinases (MMPs). Inhibition of host-derived MMPs may, therefore, slow the degradation of HL. To examine the effect of bonding procedures on the presence and activity of MMP-2, the null hypothesis tested is that MMP-2 presence is irrespective from the use of an adhesive system, and from the chlorhexidine pre-treatment. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220384 Fri, 29 Jan 2010 16:36:19 +0100 3220384 http://www.medworm.com/index.php?rid=3220383&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004606%2Fabstract%3Frss%3Dyes This study examines the benefits of the adjunctive use of chlorhexidine and ethanol on the durability of resin–dentin bonds. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220383 Fri, 29 Jan 2010 16:36:19 +0100 3220383 http://www.medworm.com/index.php?rid=3220382&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS010956410900459X%2Fabstract%3Frss%3Dyes Objectives: To evaluate the morphology of the hybrid layer of one total etch and one self-etch DBA alter water storage and the effect of the application of 2% clorhexidine on its longevity. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220382 Fri, 29 Jan 2010 16:36:19 +0100 3220382 http://www.medworm.com/index.php?rid=3220381&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004588%2Fabstract%3Frss%3Dyes Objectives. The purpose of this study was to compare the ability of two adhesion test methods to differentiate performance of three dental adhesives on uncut enamel. Materials and methods. Adhesives tested were Adper™ Scotchbond™ SE Self-Etch Adhesive (SBSE, 3M ESPE), Adper™ Prompt™ L-Pop™ (Prompt, 3M ESPE) and Adper™ Single Bond Plus (SB+, 3M ESPE). Test specimen was prepared by applying an adhesive per manufacturer's instructions on the cleaned, unground facial enamel surface of a bovine incisor tooth. The adhesive surface was build up with Filtek™ Z250 Universal Restorative (3M ESPE). Microtensile test specimen were prepared by storing the tooth for 24h in tap water at 37°C, followed by sectioning the tooth perpendicular to the bonding surface with a precision diamond sa... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220381 Fri, 29 Jan 2010 16:36:19 +0100 3220381 http://www.medworm.com/index.php?rid=3220380&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004576%2Fabstract%3Frss%3Dyes Objectives. To evaluate the bond strength of etch-and-rinse adhesives in different solvent evaporation conditions. Materials and methods. Flat dentin surfaces from thirty extracted human third molars were bonded with acid etching adhesives: (1) Scotch Bond Multi-Purpose (SBMP; 3M/ESPE) – water-based; (2) Single Bond (SB; 3M/ESPE) – ethanol/water based and Prime & Bond 2.1 (PB; Dentsply) – acetone-based. Bonded dentin surfaces were air-dried according manufacturer directions at either 21°C or 38°C. Composite buildups were constructed incrementally. After storage in water for 24h at 37°C, the specimens were prepared for microtensile bond strength testing. Data were analyzed by two-way ANOVA and Tukey test (p (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220380 Fri, 29 Jan 2010 16:36:19 +0100 3220380 http://www.medworm.com/index.php?rid=3220379&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004564%2Fabstract%3Frss%3Dyes Objectives. The purpose of this study was to compare the bond strengths of enamel/composite adhesive interface measured by cantilever bending and micro-tensile test methods. Materials and methods. Buccal surfaces of bovine incisors were flattened and subsequently composite was placed (Z250, 3M) incrementally after the application of either Adper™ Scotchbond™ SE Self-Etch Adhesive (SE) or Adper™ Single Bond Plus (SB) adhesive (Both from 3M). The samples were then cut with a low-speed cutter to obtain matchstick-shape specimens which were divided into four groups (n=30 each) according to the adhesive and test method used: SE-T, SE-B, SB-T and SB-B, where T denotes micro-tensile test and B denotes cantilever bending. The failure mode of each specimen was examined under a microscope, wi... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220379 Fri, 29 Jan 2010 16:36:18 +0100 3220379 http://www.medworm.com/index.php?rid=3220378&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004552%2Fabstract%3Frss%3Dyes Objectives. The use of self-etching adhesives (SEA) increases the dentin shear bond strength (dSBS) of resin modified glass ionomers (RMGI) . The purpose of this study was to compare the dSBS of SEA+RMGI combination with the SEA+composite resin combination, and then to test the effects of water and saliva contaminations on dSBS for this association at various stages of bonding. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220378 Fri, 29 Jan 2010 16:36:18 +0100 3220378 http://www.medworm.com/index.php?rid=3220377&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004540%2Fabstract%3Frss%3Dyes Objectives. Worldwide bond strength tests are used to evaluate bonding effectiveness of different adhesive techniques. The purpose of this study was to systematically collect these data to identify the primary parameters that affect the outcome of bond strength tests, and to attempt to disclose trends in adhesive performance of the different adhesive approaches today available. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220377 Fri, 29 Jan 2010 16:36:18 +0100 3220377 http://www.medworm.com/index.php?rid=3220376&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004539%2Fabstract%3Frss%3Dyes Objectives. The purpose of this study was to evaluate the effect of the intermediate resin layer (IRL) on bond strength and durability of single-step adhesive by examining microtensile bond strengths to dentin. In order to gain more information, the debonded beams of each group were prepared for FE-SEM to observe the fracture patterns, and the change of resin–dentin interface nanoleakage were observed using TEM. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220376 Fri, 29 Jan 2010 16:36:18 +0100 3220376 http://www.medworm.com/index.php?rid=3220375&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004527%2Fabstract%3Frss%3Dyes Objectives. To isolate the active compound on a proanthocyanidin-rich (PA) extract used to improve the mechanical properties of dentin. Materials and methods. The polymeric PAs were fractionated from grape seed extract on Sephadex LH-20 column (0.75ID×12in.) using different solvents systems (3 gradients of methanol–water, 100% methanol and 70% acetone–water). The first fractionation provided 35 fractions (Fr), which were combined into 5 Fr, based on the results of TLC (Thin Layer Chromatography) analysis. Second fractionation followed the same protocol and the thirty-five fractions were combined into twenty. One hundred and fifty fragments (1.7mm×0.5mm) of sound coronal dentin were fully demineralized and treated with the respective water dissolved fraction. Specimens were immersed ... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220375 Fri, 29 Jan 2010 16:36:18 +0100 3220375 http://www.medworm.com/index.php?rid=3220374&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004515%2Fabstract%3Frss%3Dyes Objectives. The ability of chlorhexidine (CHX) to slow the resin-dentin bonds degradation is likely related with its capacity to inhibit the collagenolytic/gelatinolytic activity of dentin. The aim of this study was to investigate the substantivity of CHX to human dentin. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220374 Fri, 29 Jan 2010 16:36:17 +0100 3220374 http://www.medworm.com/index.php?rid=3220373&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004503%2Fabstract%3Frss%3Dyes Objectives. To evaluate the effect of various collagen cross-linking agents on the thermal stability of caries-affected and sound demineralized dentin using a differential scanning calorimetry (DSC) assay. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220373 Fri, 29 Jan 2010 16:36:17 +0100 3220373 http://www.medworm.com/index.php?rid=3220372&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004497%2Fabstract%3Frss%3Dyes This study evaluated the immediate and 6-month term resin–dentin bond strength of different hydrophilicity primers bonded to acid-etched dentin saturated with water or ethanol. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220372 Fri, 29 Jan 2010 16:36:17 +0100 3220372 http://www.medworm.com/index.php?rid=3220371&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004485%2Fabstract%3Frss%3Dyes Objectives. Adequate film thickness of resin cement is needed for long-term retention of restoration. The purpose of this study was to evaluate the effect of film thickness of various resin cements on bonding efficiency in indirect composite restoration. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220371 Fri, 29 Jan 2010 16:36:17 +0100 3220371 http://www.medworm.com/index.php?rid=3220370&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004473%2Fabstract%3Frss%3Dyes Objectives. Although diamine silver fluoride (1AgF: (NH3)2AgF) stains teeth black, it is known as a very effective agent to prevent the dental caries progress . The Ammonium hexafluorosilicate (2SiF: (NH4)2SiF6), could be used as an alternative treatment without stains. The aim of this study was to determine and compare the resistance to demineralization of the enamel of permanent teeth, with SiF and AgF application. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220370 Fri, 29 Jan 2010 16:36:17 +0100 3220370 http://www.medworm.com/index.php?rid=3220369&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004461%2Fabstract%3Frss%3Dyes Objectives. The present study aimed to evaluate preventive effect of Casein Phosphopeptide–Amorphous Calcium Phosphate (CPP–ACP) paste and artificial saliva on hardness of intact enamel eroded by a Cola drink. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220369 Fri, 29 Jan 2010 16:36:17 +0100 3220369 http://www.medworm.com/index.php?rid=3220368&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS010956410900445X%2Fabstract%3Frss%3Dyes The objective of the present study was to evaluate the effect of aging on the adhesion of total-etched and self-etched fissure sealants to ground enamel of bovine teeth using thermocycling and micro-tensile tests. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220368 Fri, 29 Jan 2010 16:36:17 +0100 3220368 http://www.medworm.com/index.php?rid=3220367&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004448%2Fabstract%3Frss%3Dyes The objective of this study was to calculate the composite contraction stresses remote from and at the bonded interface using this method. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220367 Fri, 29 Jan 2010 16:36:17 +0100 3220367 http://www.medworm.com/index.php?rid=3220366&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004436%2Fabstract%3Frss%3Dyes Objectives. The aim of the study was to assess the correlation between the percentage of fillers and the colorimetric parameters of colored resin matrices used for dental composites. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220366 Fri, 29 Jan 2010 16:36:17 +0100 3220366 http://www.medworm.com/index.php?rid=3220365&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004424%2Fabstract%3Frss%3Dyes Objectives. The C-Factor is normally used to predict the shrinkage stress at composite-tooth interfaces. A study was outlined for clarifying the elements which allows providing the stress at bonded restorations interface. In theory, the stress varies as a function of the opposition to the shrinkage (substrate stiffness), the compliance, dimensions and mechanical properties of the composite. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220365 Fri, 29 Jan 2010 16:36:17 +0100 3220365 http://www.medworm.com/index.php?rid=3220364&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004412%2Fabstract%3Frss%3Dyes Objectives. To study the fracture mechanism of experimental resin composites with different filler sizes by determining their initial fracture strength (IFS), flexural fatigue limit (FFL) and by observing respective fractographic features. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220364 Fri, 29 Jan 2010 16:36:17 +0100 3220364 http://www.medworm.com/index.php?rid=3220363&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004400%2Fabstract%3Frss%3Dyes The objective of this study was to determine the influence of monomer structure/functionality on the affinity of the thiyl radical from the iniferters with the propagating carbon radical in methacrylates. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220363 Fri, 29 Jan 2010 16:36:17 +0100 3220363 http://www.medworm.com/index.php?rid=3220362&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004394%2Fabstract%3Frss%3Dyes Objectives. The purpose of this study was to evaluate the change of gloss for nanocomposite resins by toothbrushing. Materials and methods. Nine different composite resins were filled into acrylic resin mold and light cured under slide glass (control surface). Gloss was measured using Novo-curve™ glossmeter (Rhopoint, U.K.). Then composite surface was polished with Enhance® and Pogo® (Dentsply/Caulk, Milford, DE, USA) as baseline. Brushing force was 250g using a manual toothbrush (Braun oral B® Indicator Plus) with toothpaste (NAME). Gloss measurements were performed after polishing and at 200, 400, 600, 800, 1000, 2000, and 3000 (6 month-final) manual stroke. Gloss retention was calculated with the following formula. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220362 Fri, 29 Jan 2010 16:36:17 +0100 3220362 http://www.medworm.com/index.php?rid=3220361&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004382%2Fabstract%3Frss%3Dyes Objective. The elastic modulus (EM) is the main constant characterizing the stiffness of a solid material. Different methods are known to describe this parameter, as there are mechanical (static vs. dynamic) or acoustic methods. The aim here was to evaluate the influence of different measuring principles on the elastic moduli of different dental direct restoratives. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220361 Fri, 29 Jan 2010 16:36:17 +0100 3220361 http://www.medworm.com/index.php?rid=3220360&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004370%2Fabstract%3Frss%3Dyes Objectives. In this paper, a non-destructive testing technique – acoustic emission (AE) – was used to monitor the development of micro-debonding in a dental restoration during the polymerization of the dental composite. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220360 Fri, 29 Jan 2010 16:36:17 +0100 3220360 http://www.medworm.com/index.php?rid=3220359&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004369%2Fabstract%3Frss%3Dyes Objectives. The purpose of this study was to investigate, in dental neat resins, the effect of adding hyperbranched polymers (HBPs) on polymerization contraction (C), degree of conversion (DC) and elastic modulus (E). (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220359 Fri, 29 Jan 2010 16:36:17 +0100 3220359 http://www.medworm.com/index.php?rid=3220358&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004357%2Fabstract%3Frss%3Dyes Objectives. To evaluate the effect of instrument compliance on the polymerization shrinkage stress measurements of dental composites. Materials and methods. The contraction strain and stress of composites during light curing were measured by a custom made stress-strain analyzer, which consisted of a displacement sensor to measure a strain, a cantilever load cell to measure a stress, and a negative feedback mechanism to control instrument compliance. The instrument was able to measure the polymerization shrinkage stress by two modes: (1) High compliance mode (4.7μm/N) without feedback, or (2) Low compliance mode with a feedback mechanism. The shift between two modes was controlled by an On–Off switch of the negative feedback circuit. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220358 Fri, 29 Jan 2010 16:36:17 +0100 3220358 http://www.medworm.com/index.php?rid=3220357&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004345%2Fabstract%3Frss%3Dyes Objectives. Shrinkage stress is still considered to be a major drawback of resin-based composite materials. It was claimed that resin systems based on the SDR™ technology (Stress Decreasing Resin) with a Polymerization Modulator being chemically embedded in the polymerizable resin backbone, are able to induce a lower shrinkage during polymerization in composite materials. The aim of this study was therefore to analyse the shrinkage behaviour of two experimental composites based on the SDR™ technology1 in comparison to a low shrinkage silorane-based2 and 4 regular methacryate-based composites3. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220357 Fri, 29 Jan 2010 16:36:17 +0100 3220357 http://www.medworm.com/index.php?rid=3220356&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004333%2Fabstract%3Frss%3Dyes Objectives. The aim of this study was to examine microleakage at the interface between pit-and-fissure sealants and enamel using micro-CT. Materials and methods. Six extracted intact human molars were cleaned with prophylaxis paste in the region of pit and fissure. A sealant (Enamel Loc, Premier Dental) was applied in pits and fissures of all teeth. Three specimens were immersed in 50% silver nitrate solution for 24h followed by exposure in fluorescent light for 8h before being scanned in a micro-CT machine (X-tek). The other three were handled in the same way after undergoing 10,000 thermal cycles between 5°C and 55°C. The micro-CT images were evaluated in VGstudio Max software. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220356 Fri, 29 Jan 2010 16:36:17 +0100 3220356 http://www.medworm.com/index.php?rid=3220355&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004321%2Fabstract%3Frss%3Dyes Objectives. During its in vivo development, dental bonding is always under polymerization contraction stress (PCS) when there is cure-induced shrinkage and the volume change of restoration is constrained. This is not reflected, however, in our in vitro sample preparation – there is little PCS because the restorative material shrinks almost without restriction. The two conditions may in principle produce different bond strengths since the presence of stress could negatively affect the bond structure. We designed a new method to test the hypothesis. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220355 Fri, 29 Jan 2010 16:36:17 +0100 3220355 http://www.medworm.com/index.php?rid=3220354&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS010956410900431X%2Fabstract%3Frss%3Dyes Introduction. Recently, composites contaning monomers alternative to conventional dimetacrylates appeared on the market. According to the manufacturers, these new composites show lower volumetric shrinkage, which would lead to lower polymerization stress at the tooth/restoration interface. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220354 Fri, 29 Jan 2010 16:36:17 +0100 3220354 http://www.medworm.com/index.php?rid=3220353&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004308%2Fabstract%3Frss%3Dyes Objectives. Assess patterns of clinical change observed from USPHS direct evaluation categories for pooled results of 10 clinical trials for Class I and II posterior composite restorations monitored up to 10 years. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220353 Fri, 29 Jan 2010 16:36:17 +0100 3220353 http://www.medworm.com/index.php?rid=3220352&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004291%2Fabstract%3Frss%3Dyes Objectives. Lucirin-TPO (L) has been introduced in some dental resin composites for aesthetic reasons as well as to increase polymerization efficiency. However, its efficiency and potential use in photoactive resin composites has not been fully described. The aim of the present work was to compare the polymerization efficiency of L with the commonly used camphorquinone/amine (CQ) photoinitiation system and to assess its potential to allow reduction of curing time. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220352 Fri, 29 Jan 2010 16:36:16 +0100 3220352 http://www.medworm.com/index.php?rid=3220351&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS010956410900428X%2Fabstract%3Frss%3Dyes Objectives. To evaluate the effect of four collagen cross-linking agents, Glutaraldehyde (GD), Grape Seed Extract (GSE), Genipin (GE) and Tannic Acid (TA) on the Reduced Modulus of Elasticity (Er) and Nanohardness (H) of demineralized dentin. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220351 Fri, 29 Jan 2010 16:36:16 +0100 3220351 http://www.medworm.com/index.php?rid=3220350&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004278%2Fabstract%3Frss%3Dyes The objective of this study was to evaluate the influence of inorganic fraction (Fi) on polymerization stress (σpol) and its determinants: volumetric shrinkage (VS), elastic modulus (E) and degree of conversion (DC). (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220350 Fri, 29 Jan 2010 16:36:16 +0100 3220350 http://www.medworm.com/index.php?rid=3220349&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004266%2Fabstract%3Frss%3Dyes Objectives. To evaluate the effect of the ceramic material and connector size on the fracture load and fracture behavior of fixed partial dentures (FPDs). Materials and methods. Five ceramic materials were used: a yttria partially stabilized tetragonal zirconia polycrystal (Y-TZP – In-Ceram YZ, Vita), a glass-infiltrated alumina/zirconia (ICZ – In-Ceram Zirconia, Vita), a polycrystalline alumina (AL – In-Ceram AL, Vita) and two feldspathic ceramics (VM7 and VM9, Vita). Forty FPDs were produced according to the manufacturer's instructions and divided in four groups (n=10): (1) YZ-9: Y-TZP/VM9 with 9mm2 connector cross-section; (2) YZ-16: Y-TZP/VM9 with 16mm2 connector cross-section; (3) AL-16: AL/VM7 with 16mm2 connector cross-section; (4) ICZ-16: ICZ/VM7 with 16mm2 connector cross-s... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220349 Fri, 29 Jan 2010 16:36:16 +0100 3220349 http://www.medworm.com/index.php?rid=3220348&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004254%2Fabstract%3Frss%3Dyes Objectives. The purpose of this study was to evaluate, by means of tensile bond strength (TBS) test, the influence of Mefp-1-based peptides chain configuration as well as DOPA aminoacid role on chemical interaction to zirconium oxide ceramics. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220348 Fri, 29 Jan 2010 16:36:16 +0100 3220348 http://www.medworm.com/index.php?rid=3220347&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109003510%2Fabstract%3Frss%3Dyes (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220347 Fri, 29 Jan 2010 16:36:16 +0100 3220347 http://www.medworm.com/index.php?rid=3220346&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109003509%2Fabstract%3Frss%3Dyes (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220346 Fri, 29 Jan 2010 16:36:16 +0100 3220346 http://www.medworm.com/index.php?rid=3220345&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004941%2Fabstract%3Frss%3Dyes Abstract: One often alleges that laboratory bond-strength testing cannot predict clinical effectiveness of adhesives. Major argument to sustain this claim is the wide variation in bond-strength values recorded for one specific adhesive among different research institutes worldwide. The main reason for these inconsistent bond-strength measurements is supposedly the current lack of a standard bond-strength testing protocol. This paper (and presentation) aimed to report on an extensive literature review with regard to the different laboratory bond-strength test methods and their data provided, along with a second extensive literature review on clinical effectiveness data of adhesives in terms of retention rates of adhesive Class-V restorations. Combining both systematic reviews, we have subse... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220345 Fri, 29 Jan 2010 16:36:16 +0100 3220345 http://www.medworm.com/index.php?rid=3220344&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109005028%2Fabstract%3Frss%3Dyes Conclusions: Previous studies have indicated bond strength did not correlate with the results of micro-leakage tests nor gap formation at the cavity margin. The nanoleakage test and morphological and chemical characteristics of the bonding interface had potential to predict the dentin bond durability.Significance: Bond strength test results and other in vitro phenomena was not evenly correlated. According to the development of the materials, the most appropriate bond test and analysis of the in vitro phenomena should be also developed. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220344 Fri, 29 Jan 2010 16:36:16 +0100 3220344 http://www.medworm.com/index.php?rid=3220343&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109005065%2Fabstract%3Frss%3Dyes Abstract: Objective: The goal of this paper is to undertake a literature search collecting all dentin bond strength data obtained for six adhesives with four tests (shear, microshear, tensile and microtensile) and to critically analyze the results with respect to average bond strength, coefficient of variation, mode of failure and product ranking.Method: A PubMed search was carried out for the years between 1998 and 2009 identifying publications on bond strength measurements of resin composite to dentin using four tests: shear, tensile, microshear and microtensile. The six adhesive resins were selected covering three step systems (OptiBond FL, Scotch Bond Multi-Purpose Plus), two-step (Prime & Bond NT, Single Bond, Clearfil SE Bond) and one step (Adper Prompt L Pop).Results: Pooling result... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220343 Fri, 29 Jan 2010 16:36:16 +0100 3220343 http://www.medworm.com/index.php?rid=3220342&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004977%2Fabstract%3Frss%3Dyes Abstract: Dental adhesives are usually tested in shear or tension even though neither of these approaches measures the local stress triggering failure. Because the stress level varies extensively over the bonded surface, it seems as a fracture mechanics approach would be more appropriate.In this review different general aspects of fracture mechanics and adhesive joints were reviewed first. That review served as a foundation for a review of fracture toughness studies performed on dental adhesives. The dental adhesive studies were identified through a MEDLINE search using “dental adhesion testing AND enamel OR dentin AND fracture toughness” as search strategy.The outcome of the review revealed that fracture toughness studies performed on dental adhesives are complex, both regarding techn... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220342 Fri, 29 Jan 2010 16:36:16 +0100 3220342 http://www.medworm.com/index.php?rid=3220341&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109005016%2Fabstract%3Frss%3Dyes The objective of this paper is to critically review the literature regarding the mechanics, geometry, load application and other testing parameters of “micro” shear and tensile adhesion tests, and to outline their advantages and limitations. The testing of multiple specimens from a single tooth conserves teeth and allows research designs not possible using conventional ‘macro’ methods. Specimen fabrication, gripping and load application methods, in addition to material properties of the various components comprising the resin–tooth adhesive bond, will influence the stress distribution and consequently, the nominal bond strength and failure mode. These issues must be understood; as should the limitations inherent to strength-based testing of a complicated adhesive bond joining dis... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220341 Fri, 29 Jan 2010 16:36:16 +0100 3220341 http://www.medworm.com/index.php?rid=3220340&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004965%2Fabstract%3Frss%3Dyes Abstract: Objectives: Bond strength between adhesive systems and the tooth structure is influenced by a large number of variables, which makes the comparison among studies virtually impossible. Also, failure often times propagates into the dental substrate or the composite, deeming the results questionable at best. In spite of the increased popularity gained by micro-tensile and micro-shear tests, in vitro evaluations using specimens with relatively large bonding areas remain frequent. This review focuses on aspects related to specimen geometry and test mechanics of “macro” shear and tensile bond strength tests.Methods: Besides information drawn from the literature, the effect of some parameters on stress distribution at the bonded interface was assessed using finite element analysis (... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220340 Fri, 29 Jan 2010 16:36:16 +0100 3220340 http://www.medworm.com/index.php?rid=3220339&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109004953%2Fabstract%3Frss%3Dyes Abstract: The wetness of dentin surfaces, the presence of pulpal pressure, and the thickness of dentin are extremely important variables during bonding procedures, especially when testing bond strength of adhesive materials in vitro with the intention of simulating in vivo conditions. The ultimate goal of a bonded restoration is to attain an intimate adaptation of the restorative material with the dental substrate. This task is difficult to achieve as the bonding process is different for enamel and for dentin—dentin is more humid and more organic than enamel. While enamel is predominantly mineral, dentin contains a significant amount of water and organic material, mainly type I collagen. This humid and organic nature of dentin makes this hard tissue very challenging to bond to. Several o... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220339 Fri, 29 Jan 2010 16:36:16 +0100 3220339 http://www.medworm.com/index.php?rid=3220338&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109005004%2Fabstract%3Frss%3Dyes Abstract: Introduction: Resin bonding can be compared to making a sandwich with the tooth on one side and the restoration on the other, a layer of bonding resin is applied to either side and a filled resin (composite) placed in between. This presentation considers factors that influence the restoration side of the sandwich and various ways that the assembled testpieces may be “aged” prior to testing. The materials to be bonded may be either ceramic, metal or composite formed by methods such as casting, pressing, sintering or machining. The fabrication method determines the susceptibility of the bonding surface to physical or chemical modification. The treatment of the surface prior to bonding can be physical (e.g. sandblasting) or chemical (e.g. metal primer); but is more likely to be ... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220338 Fri, 29 Jan 2010 16:36:15 +0100 3220338 http://www.medworm.com/index.php?rid=3220337&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS010956410900503X%2Fabstract%3Frss%3Dyes Abstract: Objective: Adhesion or cohesion includes an adherend, adhesive, and intervening interface. Adhesive joints may include one or more interfaces. Adhesion science focuses on understanding the materials properties associated with formation of the interfaces, changes in the interfaces with time, and events associated with failure of the interfaces.Methods: The key principles for good interface formation are creation of a clean surface, generation of a rough surface for interfacial interlocking, good wetting of the substratum by the adhesive/cohesive materials, adequate flow and adaptation for intimate interaction, and acceptable curing when phase changes are required for final joint formation.Results: Much more effort is needed in the future to carefully assess each of these using ava... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220337 Fri, 29 Jan 2010 16:36:15 +0100 3220337 http://www.medworm.com/index.php?rid=3220336&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109005077%2Fabstract%3Frss%3Dyes The Academy of Dental Materials held its annual meeting in Portland, Oregon, USA, on October 29–31, 2009. The full title of the meeting was Adhesion in Dentistry – Analyzing Bond Strength Testing Methods, Variables and Outcomes. The three day conference was highlighted by nine invited speakers addressing topics in the following thematic areas: Adhesion Tests: The Science and the Testing Variables; Day 2 – Adhesion Tests: The Test Methods – Attributes and Limitations; Day 3 – Adhesion Tests: The Relationships and Outcomes. The manuscripts composed by the nine invited speakers follow this brief introduction and conclusion to the conference. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220336 Fri, 29 Jan 2010 16:36:15 +0100 3220336 http://www.medworm.com/index.php?rid=3220335&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109005156%2Fabstract%3Frss%3Dyes (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3220335 Fri, 29 Jan 2010 16:36:15 +0100 3220335 http://www.medworm.com/index.php?rid=3079260&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS010956410900311X%2Fabstract%3Frss%3Dyes Abstract: Objectives: Tubules dominate the microstructure of dentin, and in crowns of human teeth they are surrounded by thick mineralized peritubular cuffs of high stiffness. Here we examine the three-dimensional (3D) arrangement of tubules in relation to enamel on the buccal and lingual aspects of intact premolars and molars. Specifically we investigate the angular orientation of tubules relative to the plane of the junction of dentin with enamel (DEJ) by means of wet, non-destructive and high-resolution phase-contrast (coherent) tomography.Methods: Enamel capped dentin samples (n=16), cut from the buccal and lingual surfaces of upper and lower premolar and molar teeth, were imaged in water by high-resolution synchrotron-based phase-contrast X-ray radiography. Reconstructed 3D virtual im... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3079260 Fri, 11 Dec 2009 16:17:00 +0100 3079260 http://www.medworm.com/index.php?rid=3079259&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109003042%2Fabstract%3Frss%3Dyes This study shows that there are still considerable prospects for improving dental ceramics and for mimicking the enamel structure developed by nature. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3079259 Fri, 11 Dec 2009 16:17:00 +0100 3079259 http://www.medworm.com/index.php?rid=3079258&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109003030%2Fabstract%3Frss%3Dyes Abstract: Objectives: Components released from resin-based dental materials are important factors in the assessment of the biocompatibility of these materials. The study was performed to investigate the elution of substances from unpolymerized and polymerized composites (Tetric®=TET; Arabesk®=ARA), ormoceres (Admira®=ADM; Definite®=DEF) and the compomere (Hytac®=HYT).Methods: Specimens were polymerized and immersed in either water or methanol. Besides the unpolymerized specimens were dissolved in methanol. Eluted substances were detected by gas chromatography/mass spectroscopy. The Nernst partition coefficient (DC) of 64 substances, eluted from various resin-based dental materials was determined.Results: Only in methanolic and aqueous eluates from unpolymerized and polymerized specime... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3079258 Fri, 11 Dec 2009 16:17:00 +0100 3079258 http://www.medworm.com/index.php?rid=3079257&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109003029%2Fabstract%3Frss%3Dyes Abstract: Objective: To evaluate the biaxial and short-beam uniaxial strength tests applied to resin composites based upon their Weibull parameters, fractographic features and stress distribution.Methods: Disk- (15mm×1mm) and beam-shaped specimens (10mm×2mm×1mm) of three commercial composites (Concept/Vigodent, CA; Heliomolar/Ivoclar-Vivadent, HE; Z250/3M ESPE, FZ) were prepared. After 48h dry storage at 37°C, disks and beams were submitted to piston-on-three-balls (BI) and three-point bending (UNI) tests, respectively. Data were analyzed by Weibull statistics. Fractured surfaces were observed under stereomicroscope and scanning electron microscope. Maximum principal stress (σ1) distribution was determined by finite element analysis (FEA). Maximum σ1-BI and σ1-UNI were compared to F... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3079257 Fri, 11 Dec 2009 16:16:59 +0100 3079257 http://www.medworm.com/index.php?rid=3079256&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109003005%2Fabstract%3Frss%3Dyes This study investigated Candida albicans adhesion onto commercial maxillo-facial silicone elastomers based on different polymerisation processes.Methods: Room-temperature polymerised maxillo-facial silicone elastomers (N=48) (10mm×10mm×2mm) processed at different durations [VerSilTal VST-30 (20min), VST-50 (12h overnight), VST-50F (6h)] were studied. C. albicans was chosen as a model organism for this study. The specimens were randomly divided into two subgroups and incubated in either 1.5ml simulated saliva or nasal secretion containing C. albicans (ATCC 60193, set to 0.5 OD, 540nm in advance) for 2h. Candida assays and adherence assays were made by inoculating C. albicans into Mueller Hinton Broth, Fluka® added 500mmol sucrose overnight. After fixation, specimens were stained by using... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3079256 Fri, 11 Dec 2009 16:16:59 +0100 3079256 http://www.medworm.com/index.php?rid=3079255&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109002991%2Fabstract%3Frss%3Dyes Abstract: Objectives: The purpose of this in vitro study was to compare the centric and eccentric quasi-static and fatigue fracture strength of industrially prefabricated resin-bonded three-unit inlay-retained fixed dental prostheses (IPIRFDPs). The IPIRFDPs consisted of industrial manufactured yttria-stabilized tetragonal zirconia (Y-TZP) frameworks with an industrially added microhybrid composite veneering.Methods: Identical IPIRFDP-models consisted of a second premolar, a missing first molar and a second molar (CoCrMo alloy) integrated in a low melting alloy base. Roots were covered with a soft silicone layer to simulate an artificial parodontium. Premolars had an occlusal–distal inlay-preparation and molars a mesial–occlusal inlay-preparation. Forty-two IPIRFDPs with a connector si... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3079255 Fri, 11 Dec 2009 16:16:59 +0100 3079255 http://www.medworm.com/index.php?rid=3079254&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109002899%2Fabstract%3Frss%3Dyes In this study, stickiness was tested directly to the steel plunger and to dentin slices (uncovered or covered with two different bonding agents) fixed to the plunger rod with a clamp.Results: The coefficients of variation (CVs) were generally less than 0.10, indicating that the stickiness instrument offers an adequately reproducible way of testing stickiness. The tested composite materials varied significantly in stickiness. For all investigated materials a decrease of peak heights with increasing speed was found (for all three materials: p (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3079254 Fri, 11 Dec 2009 16:16:59 +0100 3079254 http://www.medworm.com/index.php?rid=3079253&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109002887%2Fabstract%3Frss%3Dyes Abstract: Objectives: Aim of this study was by continuous monitoring to assay the proliferative capacity of human gingival fibroblasts (HGFs), to investigate cytotoxicity of the most common monomers/comonomers in dental resin composites: bisphenol-A-glycidylmethacrylate (BisGMA), hydroxyethylenemethacrylate (HEMA), triethyleneglycoldimethacrylate (TEGDMA), and urethanedimethacrylate (UDMA) in HGFs during 24h exposure using the xCELLigence system.Methods: xCELLigence cell index (CI) impedance measurements were performed according to the instructions of the supplier. HGFs were resuspended in medium and subsequently adjusted to 400,000, 200,000, 100,000, and 50,000cells/mL. After seeding 100μL of the cell suspensions into the wells of the E-plate 96, HGFs were monitored every 15min for a per... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3079253 Fri, 11 Dec 2009 16:16:59 +0100 3079253 http://www.medworm.com/index.php?rid=3079252&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109002875%2Fabstract%3Frss%3Dyes Abstract: Objectives: Air-abrasion as bonding conditioning method for zirconia ceramic might compromise the mechanical strength of zirconia restorations. The purpose of this study was to evaluate the influence of surface conditioning parameters, i.e., air-abrasion with reduced pressure or no air-abrasion and priming with adhesive primers on the long-term resin bond strength to zirconia ceramic.Methods: Zirconia ceramic disks were polished with 600 grit abrasive paper. Plexiglas tubes filled with composite resin were bonded with RelyX Unicem luting composite resin to the conditioned zirconia disks. Three surface conditions (unconditioned, air-born particle abrasion at 0.05 or 0.25MPa) and four priming conditions (no priming, priming with Metal/Zirconia Primer, priming with Alloy Primer, pri... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3079252 Fri, 11 Dec 2009 16:16:59 +0100 3079252 http://www.medworm.com/index.php?rid=3079251&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109002863%2Fabstract%3Frss%3Dyes Abstract: Objective: The aim was to characterize the variations in the structure and surface dehydration of acid demineralized intertubular dentin collagen network with the variations in dentin depth and time of air-exposure (3, 6, 9 and 12min). In addition, to study the effect of these variations on the tensile bond strength (TBS) to dentin.Methods: Phosphoric acid demineralized superficial and deep dentin specimens were prepared. The structure of the dentin collagen network was characterized by AFM. The surface dehydration was characterized by probing the nano-scale adhesion force (Fad) between AFM tip and intertubular dentin surface as a new experimental approach. The TBS to dentin was evaluated using an alcohol-based dentin self-priming adhesive.Results: AFM images revealed a demineral... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3079251 Fri, 11 Dec 2009 16:16:59 +0100 3079251 http://www.medworm.com/index.php?rid=3079250&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS010956410900284X%2Fabstract%3Frss%3Dyes Abstract: Ammonium hexafluorosilicate [SiF: (NH4)2SiF6] was prepared in order to overcome the tooth discoloration caused by diamine silver fluoride [AgF: (NH3)2AgF] application. We employed a single concentration of SiF solution in our previous study; therefore, it is still unclear how the concentration of SiF solution affects the occlusion of dentin tubules and composition of the precipitate.Objective: The aim of this study was to evaluate the effects of changing the concentration of SiF on its clinical use as a dentin hypersensitivity treatment.Methods: To simulate dentin tubules subject to dentin hypersensitivity, dentin disks were treated with EDTA for 2min. Then, the disks were treated with several concentrations of SiF solution (from 100 to 19,400ppm) for 3min. The occlusion of denti... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3079250 Fri, 11 Dec 2009 16:16:58 +0100 3079250 http://www.medworm.com/index.php?rid=3079249&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109002814%2Fabstract%3Frss%3Dyes The objective of this work was to evaluate thiol-norbornene and thiol-ene–methacrylate systems as the resin phase of dental restorative materials and demonstrate their superior performance as compared to dimethacrylate materials.Methods: Polymerization kinetics and overall functional group conversions were determined by Fourier transform infrared spectroscopy (FTIR). Flexural strength and modulus were determined with a 3-point flexural test. Polymerization-induced shrinkage stress was measured with a tensometer.Results: Thiol-ene polymer systems were demonstrated to exhibit advantageous properties for dental restorative materials in regards to rapid curing kinetics, high conversion, and low shrinkage and stress. However, both the thiol-norbornene and thiol-allyl ether systems studied her... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3079249 Fri, 11 Dec 2009 16:16:58 +0100 3079249 http://www.medworm.com/index.php?rid=3079248&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109002802%2Fabstract%3Frss%3Dyes Abstract: Objectives: To investigate the chipping resistance of veneered zirconia specimens and compare it to the chipping resistance of porcelain fused to metal (PFM) specimens.Methods: Veneered zirconia and PFM bar specimens were prepared in clinically relevant thicknesses. The specimen edges were chipped with different magnitude forces, producing chips of various sizes. The range of sizes included small chips that did not penetrate all the way through the veneers to the substrates, and also chips that were very large and reached the zirconia or metal substrates. The relationship between force magnitude and chip size (edge distance) was graphed. The resulting curves were compared for the veneered zirconia and PFM specimens. Knoop hardness vs. force graphs for the veneers and substrates w... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3079248 Fri, 11 Dec 2009 16:16:58 +0100 3079248 http://www.medworm.com/index.php?rid=3079247&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109003054%2Fabstract%3Frss%3Dyes Abstract: Objectives: This paper collates some of the existing data on the clinical evaluations of resin-modified glass-ionomer cements (RMGICs) since their introduction two decades ago.Methods: The relevant literature was considered and data reviewed under the headings of retention, marginal characteristics, material deterioration, secondary caries, color stability, as well as pulpal and biological effects.Results: The retention for RMGICs is generally good, with an annual failure rate over 13 years reported as being under 3%. However, more data is required on their performance in carious situations. Regarding marginal characteristics, they exhibit margins that are likely to deteriorate over time. From the limited data on the surface characteristics, they appear to exhibit some wear and l... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3079247 Fri, 11 Dec 2009 16:16:58 +0100 3079247 http://www.medworm.com/index.php?rid=3079246&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS010956410900298X%2Fabstract%3Frss%3Dyes Abstract: Dental caries is the most prevalent non-communicable disease in the world. Its management in high-income countries over the last four decades has resulted in relatively low caries prevalence in child and adolescent populations. In low- and middle-income countries, caries management is virtually non-existent and this may lead to serious physical and mental complications, particularly in children. Toothache is predominantly treated by extracting the cavitated tooth. Absence of restorative oral care is partly due to the copying from high-income countries, of restorative treatment reliant on electrically driven equipment and often inappropriate for use in many low- and middle-income countries. Atraumatic Restorative Treatment (ART), which does not rely on electrically driven equipmen... Dental Materials journals http://www.medworm.com/rss/comments.php?id=3079246 Fri, 11 Dec 2009 16:16:58 +0100 3079246 http://www.medworm.com/index.php?rid=3079245&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109003418%2Fabstract%3Frss%3Dyes (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=3079245 Fri, 11 Dec 2009 16:16:58 +0100 3079245 http://www.medworm.com/index.php?rid=2927173&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109003017%2Fabstract%3Frss%3Dyes Abstract: Objective: The aim of the paper is to analyse an influence of the shape of the layers in photo-cured dental restorations of Class I on distribution of shrinkage stresses along the tooth-restoration interface. The study is a continuation of the previous considerations (Kowalczyk and Gambin (2008) ), where techniques, which reduce stress concentration at the top of the tooth-restoration interface, were considered. The analysis leads to proposition of new layer forming techniques, which diminish the stress peaks at the interface and prevent the crack propagation process.Methods: To find the stress distributions in the dental restoration layers and the tooth tissues the finite element method implemented in the ABAQUS (Simulia, Providence, USA) software is used. For Class I restoratio... Dental Materials journals http://www.medworm.com/rss/comments.php?id=2927173 Mon, 26 Oct 2009 16:59:45 +0100 2927173 http://www.medworm.com/index.php?rid=2927172&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109002978%2Fabstract%3Frss%3Dyes Abstract: Objectives: The aim of this study was to investigate the effect of variations in filler particle size and shape on the polymerization shrinkage–strain kinetics of resin-composites.Methods: A model series of 12 VLC resin-composites were studied. The particulate dispersed phase volume fraction was 56.7%: these filler particles were systematically graded in size, and further were either spherical or irregular. The bonded disk method was used to determine shrinkage–strain kinetics. Displacement was recorded following 40s irradiation (600mW/cm2) at 23°C (n=3). All data were captured for 60min and the final shrinkage–strain calculated.Results: For materials with spherical filler, shrinkage–strain was 2.66% (SD 0.18) for those with irregular filler it was 2.89% (SD 0.11). These... Dental Materials journals http://www.medworm.com/rss/comments.php?id=2927172 Mon, 26 Oct 2009 16:59:45 +0100 2927172 http://www.medworm.com/index.php?rid=2927171&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109002851%2Fabstract%3Frss%3Dyes Abstract: Objective: The aim of this study was to compare the photobleaching rate of CQ in different dental resins.Methods: The photodecomposition rate of CQ/amine system in bis-GMA/TEGDMA, bis-EMA and UDMA polymerizing monomers was evaluated at different light intensities. The photobleaching of the CQ was studied by monitoring the decrease in light absorption as a function of continuous irradiation time. The absorption changes were assessed by recording the transmitted light that passed through samples of monomers containing CQ/amine.Results: Complete photobleaching of CQ was observed in all the monomer tested and the rate constant for the photobleaching was proportional to the radiation intensity. Hydrogen abstraction from amines by the excited CQ state via electron transfer and direct h... Dental Materials journals http://www.medworm.com/rss/comments.php?id=2927171 Mon, 26 Oct 2009 16:59:44 +0100 2927171 http://www.medworm.com/index.php?rid=2927170&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109002784%2Fabstract%3Frss%3Dyes Abstract: Objectives: Several mechanisms have been purported to describe how mouthguards protect the orofacial complex against injury. As the properties needed for these mechanisms to be effective are temperature and frequency dependent, the specific aim of this study was to provide a comprehensive thermal characterization of commercial mouthguard materials.Methods: Five commercially representative thermoplastic mouthguard materials (Essix™ Resin, Erkoflex™, Proform™-regular, Proform™-laminate, and Polyshok™) were tested. Differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) techniques were implemented to measure thermal transitions and mechanical properties. Measurements were conducted three times per sample. One-way ANOVA and one-sample t-tests were used... Dental Materials journals http://www.medworm.com/rss/comments.php?id=2927170 Mon, 26 Oct 2009 16:59:44 +0100 2927170 http://www.medworm.com/index.php?rid=2927169&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109002772%2Fabstract%3Frss%3Dyes Conclusion: Filler particle size and morphology influences Fmax and Ws of uncured resin-composite which partly express the handling behaviors of resin-composites. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=2927169 Mon, 26 Oct 2009 16:59:44 +0100 2927169 http://www.medworm.com/index.php?rid=2927168&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109002681%2Fabstract%3Frss%3Dyes Abstract: Objectives: The purpose of this study was to investigate the effect of light-curing protocol on degree of conversion (DC), volume contraction (C), elastic modulus (E), and glass transition temperature (Tg) as measured on a model polymer. It was a further aim to correlate the measured values with each other.Methods: Different light-curing protocols were used in order to investigate the influence of energy density (ED), power density (PD), and mode of cure on the properties. The modes of cure were continuous, pulse-delay, and stepped irradiation. DC was measured by Raman micro-spectroscopy. C was determined by pycnometry and a density column. E was measured by a dynamic mechanical analyzer (DMA), and Tg was measured by differential scanning calorimetry (DSC). Data were submitted to... Dental Materials journals http://www.medworm.com/rss/comments.php?id=2927168 Mon, 26 Oct 2009 16:59:44 +0100 2927168 http://www.medworm.com/index.php?rid=2927167&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS010956410900267X%2Fabstract%3Frss%3Dyes The objective of this work was to further investigate the performance of dentin adhesives containing a new monomer, with particular emphasis on the water sorption and viscoelastic behavior of the crosslinked networks.Materials and methods: Dentin adhesives contained 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy) phenyl]-propane (BisGMA), 2-hydroxyethyl methacrylate (HEMA), and a new multifunctional methacrylate with urethane-linked groups-1,1,1-tri-[4-(methacryloxyethylaminocarbonyloxy)-phenyl]ethane (MPE) and were photo-polymerized in the presence or absence of water. Adhesives were characterized with regard to degree of conversion (DC), viscosity, water sorption/solubility, and dynamic mechanical analysis (DMA) and compared with BisGMA/HEMA controls.Results: The experimental adhesives exhib... Dental Materials journals http://www.medworm.com/rss/comments.php?id=2927167 Mon, 26 Oct 2009 16:59:44 +0100 2927167 http://www.medworm.com/index.php?rid=2927166&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109002668%2Fabstract%3Frss%3Dyes Abstract: Objectives: The purpose of this study was to investigate the effect of the resin matrix composition on the translucency of experimental dental composite resins.Methods: Three types of unfilled resin matrices (TEGDMA-, UDMA- and BisGMA-based) were formulated and light cured. In addition, six different experimental dental composite resins with constant filler loading but varying in the type of monomer and the content of BisGMA were fabricated. Discs of each test material with 15.5mm diameter and 1.0mm thickness were prepared (N=3) and light cured. Total and diffuse transmittance values for each sample were measured using a UV/VIS spectrophotometer with the range of readings from 380 to 700nm. Difference in color was measured using the CIE Lab system.Results: Statistical analysis by... Dental Materials journals http://www.medworm.com/rss/comments.php?id=2927166 Mon, 26 Oct 2009 16:59:44 +0100 2927166 http://www.medworm.com/index.php?rid=2927165&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109002656%2Fabstract%3Frss%3Dyes Abstract: Objectives: Camphorquinone (CQ) is cytotoxic in cell cultures. The mechanism of this toxic action, however, is not yet clearly understood. Aim of this investigation was to analyze the effects of non-irradiated CQ on intracellular formation of reactive oxygen species (ROS), intracellular glutathione (GSH) content, and the integrity of DNA in cultured primary human gingival fibroblasts (HGF).Methods: Cells were exposed to CQ at concentrations ranging between 0.05mM and 2.5mM. Intracellular levels of ROS were detected by the fluorescent probe 2′,7′-dichlorofluorescein diacetate (DCFH-DA) and GSH was determined by the fluorescent probe monobromobimane (MBBr). Genotoxicity was measured quantitatively by the alkaline comet assay. The cytotoxic effects of CQ were investigated by mea... Dental Materials journals http://www.medworm.com/rss/comments.php?id=2927165 Mon, 26 Oct 2009 16:59:43 +0100 2927165 http://www.medworm.com/index.php?rid=2927164&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109002644%2Fabstract%3Frss%3Dyes This study investigated the cytotoxicity of elemental ions contained in four fixed prosthodontic materials (gold, nickel–chromium, stainless-steel alloys and CAD–CAM ceramics).Materials and methods: According to the determination of elements released from prosthodontic materials by using inductively coupled plasma mass spectroscopy, similar amounts of elements Pd, Ag, Zn, Cu, Ni, Cr, Mo, Be, Fe, Al, and K were prepared as salt solutions. Wells with a tenfold higher concentration of the tested elements were used as positive controls, while a well without any tested element was used as a negative control. These salt solutions were tested for cytotoxicity by culturing mouse L-929 fibroblasts in the salt solutions for a 7-day period of incubation. Then, the percentage of viable cells for e... Dental Materials journals http://www.medworm.com/rss/comments.php?id=2927164 Mon, 26 Oct 2009 16:59:43 +0100 2927164 http://www.medworm.com/index.php?rid=2927163&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109002632%2Fabstract%3Frss%3Dyes Abstract: Objective: To evaluate the influence of contamination and cleaning procedures on shear bond strength (SBS) to modified zirconia surfaces.Methods: One hundred zirconium-oxide ceramic disks fabricated with a rough modified surface (Nobel Bond), which allows more micromechanical interlocking for adhesive cementation, were divided into five groups. Groups were contaminated with organic (OC; human blood and saliva) and/or inorganic contaminants (IC; type IV dental stone). For cleaning, modified surfaces were etched with phosphoric acid for 1min (PA) or fired in a ceramic furnace up to 910°C and cleaned in an ultrasonic bath in ethanol (FU). Following combinations of contamination and cleaning protocols were chosen: group 1: OC-PA; group 2: IC-FU; group 3: OC+IC-PA+FU; group 4: OC+IC-... Dental Materials journals http://www.medworm.com/rss/comments.php?id=2927163 Mon, 26 Oct 2009 16:59:43 +0100 2927163 http://www.medworm.com/index.php?rid=2927162&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109002620%2Fabstract%3Frss%3Dyes This study provides a basis to explore NAC-containing biomaterials that are functionalized to control oral soft tissue growth and function without cytotoxicity. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=2927162 Mon, 26 Oct 2009 16:59:43 +0100 2927162 http://www.medworm.com/index.php?rid=2927161&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109002619%2Fabstract%3Frss%3Dyes Abstract: Objective: Shear fatigue limit (SFL) testing, coupled with shear bond strength (SBS) measurements can provide valuable information regarding the ability of adhesive systems to bond to mineralized tooth structures. The clinical technique for enamel bonding with adhesive resins has shifted from bonding to a thoroughly dried acid conditioned surface to a moist surface to facilitate dentin bonding. The purpose of this study was to compare the performance of ethanol-containing etch-and-rinse adhesive (ERA) systems on moist and dry enamel by determining the resin composite to enamel SBS and SFL, and examining the relationship of SBS and SFL.Methods: Twelve specimens each were used to determine 24-h resin composite (Z100 – 3M ESPE) to enamel SBS to moist and dry surfaces with two ERA ... Dental Materials journals http://www.medworm.com/rss/comments.php?id=2927161 Mon, 26 Oct 2009 16:59:43 +0100 2927161 http://www.medworm.com/index.php?rid=2927160&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109002607%2Fabstract%3Frss%3Dyes Abstract: Objectives: Streptococcus mutans is considered a major causative of tooth decay due to its ability to rapidly metabolize carbohydrates such as sucrose. One prominent excreted end product of sucrose metabolism is lactic acid. Lactic acid causes a decrease in the pH of the oral environment with subsequent demineralization of the tooth enamel. Biologically relevant bacteria-induced enamel demineralization was studied.Methods: Optical profiling was used to measure tooth enamel decay with vertical resolution under one nanometer and lateral features with optical resolution as a result of S. mutans biofilm exposure. Comparison measurements were made using AFM.Results: After 72h of biofilm exposure the enamel displayed an 8-fold increase in the observed roughness average (Ra), as calcula... Dental Materials journals http://www.medworm.com/rss/comments.php?id=2927160 Mon, 26 Oct 2009 16:59:42 +0100 2927160 http://www.medworm.com/index.php?rid=2927159&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109002590%2Fabstract%3Frss%3Dyes Abstract: Objectives: The aim of this study was to evaluate the setting characteristics of low-shrinking resin composites and examine the possible interactions with curing efficiency and marginal adaptation in dentin cavities.Methods: The materials tested were Ceram X Mono/CM, Premise/PR, Clearfil Majesty/CM, ELS/EL, and Filtek Silorane/FS. Polymerization shrinkage strain (%S), strain rate (%Sr) and time at maximum strain rate (tmax) were measured using the bonded disk method. Curing efficiency was measured on the top and bottom surfaces of composites with ATR-FTIR spectroscopy. Marginal adaptation was measured in unbonded (%VVF) and bonded (%XVF) specimens by computerized X-ray microtomography (micro-XCT). The % linear length of the interfacial gaps along the cavity margins (%LD) and the ... Dental Materials journals http://www.medworm.com/rss/comments.php?id=2927159 Mon, 26 Oct 2009 16:59:42 +0100 2927159 http://www.medworm.com/index.php?rid=2927158&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109002589%2Fabstract%3Frss%3Dyes Abstract: Objective: To evaluate the influence of tetrahydrofuran (THF) on the resin-to-dentin microtensile bond strength (μTBS) after water storage, for 24h and 6 months, and to compare its behavior with that of traditional solvents.Methods: Seven versions of monomer/solvent mixtures (primers) were prepared using the following solvent and water combinations: (1) THF, (2) acetone, (3) ethanol, (4) water, (5) THF/water, (6) acetone/water and (7) ethanol/water. An experimental adhesive resin was also synthesized to compare adhesive systems with the different primers. Forty-two bovine incisors, randomly separated into seven groups, had their superficial coronal dentin exposed. After acid-etching and rinsing, the excess water was removed from the surface with absorbent paper. Each experimenta... Dental Materials journals http://www.medworm.com/rss/comments.php?id=2927158 Mon, 26 Oct 2009 16:59:42 +0100 2927158 http://www.medworm.com/index.php?rid=2927157&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109002565%2Fabstract%3Frss%3Dyes Conclusion: The effect of irradiation time on the mechanical behavior was introduced through its effect on the models’ parameters. The hypothesis was rejected since changes were observed in the model parameters. (Source: Dental Materials) Dental Materials journals http://www.medworm.com/rss/comments.php?id=2927157 Mon, 26 Oct 2009 16:59:42 +0100 2927157 http://www.medworm.com/index.php?rid=2927156&cid=s_35508_173_f&fid=35508&url=http%3A%2F%2Fwww.demajournal.com%2Farticle%2FPIIS0109564109002553%2Fabstract%3Frss%3Dyes This study investigated the effects of light penetration and removal of smear layer on the adhesive properties of self-etching adhesives to root canal dentin when using fiber posts.Methods: Altogether 54 human incisors and premolars were decoronated, and the roots after preparing the post space were randomly assigned into six groups. Three groups were treated with a light-cured self-etching adhesive and the other three with a dual-cured self-etching adhesive. In a further sub-division, the first group was light-cured with an irradiation unit; the second was light-cured with the irradiation unit and a light-guiding attachment; and the third was light-cured with the irradiation unit and the attachment after removing smear layer by EDTA and NaOCl. Then, a glass-fiber post was luted into the p... Dental Materials journals http://www.medworm.com/rss/comments.php?id=2927156 Mon, 26 Oct 2009 16:59:41 +0100 2927156