Brazilian Oral Research via MedWorm.com

In vitro evaluation of the microhardness of bovine enamel exposed to acid solutions after bleaching

Brazilian Oral Research — Sat, 10 Dec 2011 05:20:31 +0100

Acid erosion is a superficial loss of enamel caused by chemical processes that do not involve bacteria. Intrinsic and extrinsic factors, such as the presence of acid substances in the oral cavity, may cause a pH reduction, thus potentially increasing acid erosion. The aim of this study was to evaluate the microhardness of bleached and unbleached bovine enamel after immersion in a soda beverage, artificial powder juice and hydrochloric acid. The results obtained for the variables of exposure time, acid solution and substrate condition (bleached or unbleached enamel) were statistically analyzed by the ANOVA and Tukey tests. It was concluded that a decrease in microhardness renders dental structures more susceptible to erosion and mineral loss, and that teeth left unbleached show higher value...

Effect of vegetable oil (Brazil nut oil) and mineral oil (liquid petrolatum) on dental biofilm control

Brazilian Oral Research — Sat, 10 Dec 2011 05:20:31 +0100

Dental biofilm control represents a basic procedure to prevent caries and the occurrence of periodontal diseases. Currently, toothbrushes and dentifrices are used almost universally, and the employment of good oral hygiene allows for appropriate biofilm removal by both mechanical and chemical control. The aim of this study was to evaluate the effectiveness of adding vegetable or mineral oil to a commercially available dentifrice in dental biofilm control. A comparison using the Oral Hygiene Index Simplified (OHI-S) was performed in 30 individuals who were randomly divided into three groups. Group 1 (G1) received a commercially available dentifrice; the composition of this dentifrice was modified by addition of mineral oil (Nujol®) for group 2 (G2) or a vegetable oil (Alpha Care®) for gro...

Salivary IgA and periodontal treatment needs in diabetic patients

Brazilian Oral Research — Sat, 10 Dec 2011 05:20:31 +0100

In conclusion, diabetic individuals had lower s-IgA levels, more-frequent and more-severe periodontal disease, and a greater need for periodontal treatment as compared with non-diabetic patients. (Source: Brazilian Oral Research)

Gingival inflammation and platelet count in patients with leukemia: preliminary results

Brazilian Oral Research — Sat, 10 Dec 2011 05:20:31 +0100

Leukemia has been associated with oral manifestations. However, the available literature on this topic consists of mostly reports of cases, without data about the periodontal parameters that may be under the influence of hematologic factors. The aim of this cross-sectional study was to assess the correlation between the Gingival Index and Bleeding on Probing with the platelet count in patients with leukemia. Patients with diagnosis of any kind of leukemia, at any stage of treatment, having a minimum age of 14 years, treated at the Department of Hematology-Oncology of the University Hospital of Santa Maria, Brazil, between December 2009 and March 2010, were assessed. Excluded patients were: edentulous, with orthodontic appliances, with psychomotor disturbances, requiring antibiotic prophyla...

Influence of different durations of estrogen deficiency on alveolar bone loss in rats

Brazilian Oral Research — Sat, 10 Dec 2011 05:20:31 +0100

The purpose of this study was to morphometrically evaluate the influence of different durations of ovariectomy-induced estrogen deficiency on alveolar bone loss associated with ligature-induced bone loss in rats. Sixty female Wistar rats were randomly assigned to ovariectomy (OVX test group) or sham operation (SHAM control group). The OVX and SHAM groups were each distributed into three subgroups of ten rats each according to the duration of estrogen deficiency (30, 60 and 90 postoperative days). In all groups, for the last 30 days of the experimental period, cotton ligatures were placed around the cervix of the right upper second molar; the contralateral tooth was left unligated to serve as a control. The maxillary bones were removed, and the alveolar bone loss was analyzed by measuring t...

Developmental enamel defects and their impact on child oral health-related quality of life

Brazilian Oral Research — Sat, 10 Dec 2011 05:20:31 +0100

This cross-sectional study assessed the impact of Developmental Enamel Defects (DED) on Child Oral Health-Related Quality of Life (COHRQoL). A sample of 944 11- to 14-year-old Brazilian schoolchildren was examined for the prevalence and severity of DED. The children completed the Child Perceptions Questionnaire (CPQ11-14), and socioeconomic status was also collected using a questionnaire. Poisson regression models were used to assess the association between DED and overall and domain-specific CPQ11-14 scores. The prevalence of DED was 19.7%. In general, children with DED did not indicate any decrease in self-perception. However, this condition was associated with an impact on the functional limitation domain. The presence of DED may cause negative impacts on a child's perception of oral he...

Frictional resistance of orthodontic wires tied with 3 types of elastomeric ligatures

Brazilian Oral Research — Sat, 10 Dec 2011 05:20:31 +0100

The aims of this study were to determine and compare frictional resistance obtained by low-friction and conventional elastomeric ligatures in the presence of artificial saliva, and observe whether this variable changed after 21 days. Super Slick® low-friction elastomeric ligatures and conventional ligatures of the brands TP conventional® and Unitek® were placed on standard edgewise maxillary central incisor metal brackets, slot .022" × .028" tying rectangular orthodontic wires .018" × .025". Three experimental groups were arranged according to the type of ligature and a control group in which no wires were used. The friction values obtained between the bracket/wire/ligature set were measured using a Universal Test Machine at a speed of 20 mm/minute, at two experimental time intervals:...

In vitro cytotoxic effects of Brazilian plant extracts on squamous cell carcinoma of the oral cavity

Brazilian Oral Research — Sat, 10 Dec 2011 05:20:31 +0100

Squamous cell carcinoma (SCC) is the most prevalent cancer of the oral cavity and the fifth most prevalent of all malignancies in males. Many researchers have attempted to develop new treatments that will improve the prognosis of SCC patients. Over 20% of the world's biodiversity is located within the Brazilian forests, but little is known about the chemical and/or pharmacological potential of these plants. Certain extracts obtained from Amazon and Atlantic Forest plants have previously been shown to have cytotoxic activity against various cancers. The aim of this study was to screen these extracts for cytotoxic activity against oral SCC cells. The extracts were analyzed for activity against the KB-ADL#12 cell line at various concentrations up to a maximum dose of 100 µg/mL. Comparisons w...

Oral cancer staging established by magnetic resonance imaging

Brazilian Oral Research — Sat, 10 Dec 2011 05:20:31 +0100

The aim of this study was to compare clinical staging and magnetic resonance imaging (MRI) staging for oral cancer, and to assess inter-observer agreement between oral and medical radiologists. A total of 10 patients diagnosed with oral cancer were assessed before treatment. A head and neck surgeon performed clinical TNM staging. Two medical radiologists and two oral radiologists performed a new staging assessment by interpreting MRI scans, without prior knowledge of the clinical staging. They evaluated the extent of the primary tumor (T), metastasis to regional lymph nodes (N) and grouping by stages. The data were analyzed using the Kappa Index. There was significant agreement (p < 0.05) between the clinical and MRI staging assessments made by one oral radiologist for N stage, and between...

Effect of occlusal splint thickness on electrical masticatory muscle activity during rest and clenching

Brazilian Oral Research — Sat, 10 Dec 2011 05:20:31 +0100

The extent of separation between the maxillary and mandibular teeth in the fabrication of interocclusal splints designed to achieve efficiency and muscle relaxation is controversial and undefined in the literature. Based on this premise, the aim of this study was to evaluate the effect of interocclusal splint thicknesses of 3 and 6 millimeters on the electrical activity of the anterior temporal and masseter muscles during rest and dental clenching. Twenty asymptomatic individuals (10 males and 10 females) were selected using the Research Diagnostic Criteria (RDC). Electromyography (EMG) was performed both with and without the 3- and 6-mm splints using the Bio EMG software package, which recorded values given in microvolts (µV). The results, which were assessed using analysis of variance (...

Effect of titanium surface on secretion of IL1β and TGFβ1 by mononuclear cells

Brazilian Oral Research — Sat, 10 Dec 2011 05:20:31 +0100

Mononuclear cells play an important role in the modulation of healing. The characteristics of implant surface topography may alter the production of signaling molecules such as cytokines. The aim of this in vitro study was to evaluate the effects of commercially available titanium surface treatments on both cell viability and the secretion of the antagonist cytokines, IL1β and TGFβ1. Human mononuclear cells were cultured on 10 mm diameter commercially pure titanium (cpTi) disks that were prepared using a turning procedure (control=machined surface) and either acid etched or bio-anodized for 1-7 days. Adhered cells were investigated with respect to cell viability using an MTT assay, and cytokine production was verified using an ELISA assay. The results indicate that surface characteristic...

Effect of a cordless retraction paste material on implant surfaces: an in vitro study

Brazilian Oral Research — Sat, 10 Dec 2011 05:20:31 +0100

Cordless retraction paste material for gingival retraction in implant dentistry has recently become of interest to the clinician. However, few studies have been conducted on the use of retraction pastes and their possible interaction with implant surfaces. This in vitro study evaluated the effect of a cordless retraction paste material, Expasyl® (Acteon), on TiUnite® (Nobel Biocare) implant surfaces. Three areas of the fixtures were evaluated before and after contact with the retraction paste using scanning electron microscopy to evaluate changes in surface topography and energy-dispersive spectroscopy to identify any surface chemistry modifications. Alteration of the initial surface after exposure to Expasyl® was identified, with the implant collar showing the most changes. (Source: Br...

Effects of different surface treatments and accelerated artificial aging on the bond strength of composite resin repairs

Brazilian Oral Research — Sat, 10 Dec 2011 05:20:31 +0100

The purpose of the present study was to assess the bond strength of composite resin repairs subjected to different surface treatments and accelerated artificial aging. 192 cylindrical samples (CSs) were prepared and divided into 24 groups (n = 8). Half of the CSs were stored in water for 24 h, and the other half were subjected to C-UV accelerated aging for non-metallic specimens. The treatments were phosphoric acid + silane + adhesive (PSA); phosphoric acid + adhesive (PA); diamond bur + phosphoric acid + silane + adhesive (DPSA); diamond bur + phosphoric acid + adhesive (DPA); air abrasion + phosphoric acid + silane + adhesive (APSA); and air abrasion + phosphoric acid + adhesive (APA). The repair was performed and the specimens were again aged as described above. A control group (n = 8) ...

Impact of the implantation of a new curriculum in the process of learning in a Faculty of Dentistry in Brazil

Brazilian Oral Research — Sat, 10 Dec 2011 05:20:31 +0100

The aim of the present study was to evaluate two dental curricula at a school of dentistry in southern Brazil. The study population included dentists trained in the last two classes of the institution's old curriculum (n = 98) and graduates of the first two classes of the new curriculum (n = 56). A questionnaire with open and closed questions was used for an overall evaluation of different aspects of the curricula, such as study methods, importance given to basic sciences, quality of theoretical and clinical guidance, perception about skills needed to perform different dental procedures, professional goals and an overall assessment. Students in the new curriculum reported more frequent use of the internet (69.6%) and scientific articles (50.0%). More importance was given to the basic scien...

Editorial

Brazilian Oral Research — Sat, 10 Dec 2011 05:20:31 +0100

(Source: Brazilian Oral Research)

Halitosis: an overview of epidemiology, etiology and clinical management

Brazilian Oral Research — Sat, 22 Oct 2011 04:12:50 +0100

Halitosis is an unpleasant condition that causes social restraint. Studies worldwide indicate a high prevalence of moderate halitosis, whereas severe cases are restricted to around 5% of the populations. The etiological chain of halitosis relates to the presence of odoriferous substances in exhaled air, especially the volatile sulphur compounds (VSC) produced by bacteria. The organoleptic diagnosis is the gold standard and clinical management includes oral approaches, especially periodontal treatment and oral hygiene instructions, including the tongue. When oral strategies are not successful, referral to physicians is warranted. (Source: Brazilian Oral Research)

Effect of tetracycline on the bond performance of etch-and-rinse adhesives to dentin

Brazilian Oral Research — Sat, 22 Oct 2011 04:12:50 +0100

This study evaluated the effect of modified tetracycline on the resin-dentin bond strength (µTBS), silver nitrate uptake (SNU) and solution homogeneity (SH) of two adhesives. Dentin surfaces were treated with phosphoric acid, rinsed off and either rewetted with water (control group - CO), 2% minocycline (MI), 2% doxycyline (DO) or 2% chlorhexidine (CH). Adhesive systems (Adper Single Bond 2 and Prime Bond NT) and composite were applied and light-polymerized. Specimens were sectioned to obtain bonded sticks (0.8 mm²) to test under tension at 0.5 mm/min. For SNU, specimens were immersed in silver nitrate and analyzed by EDX-SEM. SH was qualitatively analyzed after mixing the adhesives with different solvent-based solutions containing MI, DO and CH. Lower µTBS values were observed in the D...

Effects of different concentrations of carbamide peroxide and bleaching periods on the roughness of dental ceramics

Brazilian Oral Research — Sat, 22 Oct 2011 04:12:50 +0100

This study provided evidence that at-home bleaching systems do not cause detrimental effects on surface roughness of dental ceramics. (Source: Brazilian Oral Research)

Chewing side, bite force symmetry, and occlusal contact area of subjects with different facial vertical patterns

Brazilian Oral Research — Sat, 22 Oct 2011 04:12:50 +0100

The objective of this study was to evaluate chewing side preference and lateral asymmetry of occlusal contact area and bite force of individuals with different craniofacial patterns. Seventy-eight dentate subjects were divided into 3 groups according to the VERT index as follows: (1) mesofacial, (2) brachyfacial and (3) dolichofacial. Chewing side preference was evaluated using jaw tracking equipment, occlusal contact area was measured by silicon registration of posterior teeth, and bite force was measured unilaterally on molar regions using 2.25 mm-thick sensors. Statistical analysis was performed using ANOVA on Ranks, Student's t-test, and Mann-Whitney tests at a 5% significance level. Mesofacial, brachyfacial, and dolichofacial subjects presented more occlusal contact area on the left s...

Prevalence and predictive factors of sleep bruxism in children with and without cognitive impairment

Brazilian Oral Research — Sat, 22 Oct 2011 04:12:50 +0100

Studies have found a higher prevalence of sleep bruxism (SB) in individuals with cognitive impairment. The aim of this study was to identify the prevalence and factors associated with the clinical manifestation of SB in children with and without cognitive impairment. The sample was made up of 180 individuals: Group 1 - without cognitive impairment; Group 2 - with Down syndrome; Group 3 - with cerebral palsy. Malocclusions were assessed based on the Dental Aesthetic Index (DAI); lip competence was assessed based on Ballard's description. The bio-psychosocial characteristics were assessed via a questionnaire and clinical exam. Statistical analysis involved the chi-square test (p < 0.05) and multivariate logistic regression. The prevalence of bruxism was 23%. There were no significant differe...

Combination effect of fluoride dentifrices and varnish on deciduous enamel demineralization

Brazilian Oral Research — Sat, 22 Oct 2011 04:12:50 +0100

The aim of this study was to evaluate the anticaries potential of 500 or 1100 ppm F dentifrices combined with fluoride varnish using a pH-cycling regimen. Seventy primary canines were covered with nail polish, leaving a 4×4 mm window on their buccal surface, and randomly assigned into 7 groups (n = 10): S: sound enamel not submitted to the pH-cycling regimen or treatment; N: negative control, submitted to the pH-cycling regimen without any treatment; D1 and D2: subjected to the pH-cycling regimen and treated twice daily with 1100 or 500 ppm F dentifrice, respectively; VF: fluoride varnish (subjected to F-varnish before and in the middle of the pH-cycling regimen); and VF+D1 and VF+D2. After 10 days, the teeth were sectioned, and enamel demineralization was assessed by cross-sectional hard...

Is miniscrew primary stability influenced by bone density?

Brazilian Oral Research — Sat, 22 Oct 2011 04:12:50 +0100

Primary stability is absence of mobility in the bone bed after mini-implant placement and depends on bone quality among other factors. Bone quality is a subjective term frequently considered as bone density. The aim of this preliminary study was to evaluate bone density in two bovine pelvic regions and verify the primary stability of miniscrews inserted into them. Forty bone blocks were extracted from bovine pelvic bones, 20 from iliac and 20 from pubic bone, all of them containing cortical bone about 1 mm thick. Half of the sections extracted from each bone were designated for histological evaluation of bone density (trabecular bone area - TBA) and the other half for bone mineral density (BMD) evaluation by means of central dual-energy X-ray absorptiometry (DEXA). Then, twenty self-drilli...

Prognostic factors in patients with jaw sarcomas

Brazilian Oral Research — Sat, 22 Oct 2011 04:12:50 +0100

The aim of this study was to identify the prognostic factors related to the survival of patients with sarcomas of the jaw treated in the Dr. Eduardo Caceres Graziani National Institute for Neoplastic Diseases, Lima, Peru. Age, gender, delay in consultation, diagnostic delay, therapeutic delay, tumor size, tumor location, facial asymmetry, pain, treatment type, and histopathological diagnosis were all evaluated as possible prognostic factors that would influence survival in those with jaw sarcomas. In the analysis, the following was used: mortality tables, Kaplan-Meier's product-limit method, log-rank, and Breslow and Tarone-Ware tests; for the prognostic factors, Cox's Regression Model was used. The overall survival rate, with the patient being free from disease at two years, was 55%, and ...

Response of peripheral blood mononuclear cells to conditioned medium from cultured oral squamous cell carcinomas

Brazilian Oral Research — Sat, 22 Oct 2011 04:12:50 +0100

The current study investigated the capacity for tumor factors secreted by head and neck squamous cell carcinoma (HNSCC) cell lines, KB, KB16, and HEP, to induce the secretion of various cytokines from peripheral blood mononuclear cells (PBMCs). PBMCs were isolated from blood samples collected from six healthy volunteers and these cells were incubated for 6, 24, 48, or 72 hours in the presence of 50% conditioned medium collected from cultured cell lines pretreated with, or without, stimulants such as phytohemagglutinin (PHA) or lipopolysaccharides (LPS). Aliquots of each supernatant were then assayed for levels of IFN-Γ, vascular endothelial growth factor (VEGF), TNF-α, and IL-4 using enzyme linked immunosorbent assays (ELISAs). Data collected were analyzed using Student's t-test, an ANOV...

Evaluation of caries-affected dentin with optical coherence tomography

Brazilian Oral Research — Sat, 22 Oct 2011 04:12:50 +0100

In conclusion, OCT was shown to be an efficient and non-invasive method to detect the depths of lesions caused by demineralization. Further, a seven-day demineralization time was considered sufficient for caries-affected dentin to be obtained. (Source: Brazilian Oral Research)

Influence of consumption of probiotics on presence of enterobacteria in the oral cavity

Brazilian Oral Research — Sat, 22 Oct 2011 04:12:50 +0100

In conclusion, probiotic consumption had some influence on enterobacterial presence in the oral cavity, but did not affect enterobacterial counts or the specific immune secretory response against them. (Source: Brazilian Oral Research)

Oral mucosa alterations in a socioeconomically deprived region: prevalence and associated factors

Brazilian Oral Research — Sat, 22 Oct 2011 04:12:50 +0100

This study aimed to evaluate the prevalence and factors associated with oral mucosa alterations in patients from Vale do Jequiti-nhonha, Brazil. The sample consisted of 511 patients of both genders. Questionnaires were used to obtain information about patient gender, age, race, systemic disease state, medication use, cigarette use and alcohol consumption. Physical examinations were then performed to identify lesions of the oral mucosa. Descriptive analyses, Chi-squared tests and logistic regressions were then used to analyze the results (p < 0.05, 95% CI). In this population, 84.9% (434/511) of patients were found to have alterations in their oral mucosa. The most common alterations were melanotic maculae (36.0%), linea alba (33.9%), traumatic ulcers (21.5%), Fordyce's granules (20.4%), co...

Influence of chlorhexidine application on longitudinal adhesive bond strength in deciduous teeth

Brazilian Oral Research — Sat, 22 Oct 2011 04:12:50 +0100

The aim of this study was to evaluate the influence of applying 2% chlorhexidine for 30 seconds after phosphoric acid conditioning of dentin on the immediate and long-term bond strengths in deciduous teeth. The occlusal enamel was removed from 40 human sound deciduous molars, which were exfoliated by natural means, and the dentin was conditioned with 37% phosphoric acid for 15 seconds and washed with running water. The specimens were divided into two groups of 20 teeth. The test group received an application of 2% chlorhexidine for 30 seconds prior to a three-step etch-and-rinse adhesive system, whereas the control group received only the adhesive system. Three cylindrical restorations were made with a composite resin for each tooth. Ten teeth in each group were submitted to a microshear b...

Timing of fluoride toothpaste use and enamel-dentin demineralization

Brazilian Oral Research — Sat, 22 Oct 2011 04:12:50 +0100

It is well established that fluoride (F) prevents caries development by inhibiting demineralization and enhancing remineralization processes. However, it is not known which of these protective mechanisms is more important. In this double-blind, crossover in situ study conducted in three phases of 14 days each, 12 volunteers wore palatal appliances containing enamel and root dentin slabs, on which biofilm was allowed to accumulate under exposure to 20% sucrose solution 8×/day. F toothpaste was used once a day, either before the daily demineralizing episodes (in the morning) or after them (at night). Non-F placebo toothpaste was used in the control group. F toothpaste significantly reduced enamel and dentin demineralization compared with the control (p < 0.05). F toothpaste was more effecti...

Development of dental clinical research in Brazil: a few (new) ethical challenges

Brazilian Oral Research — Sat, 22 Oct 2011 04:12:50 +0100

(Source: Brazilian Oral Research)

Interaction between staining and degradation of a composite resin in contact with colored foods

Brazilian Oral Research — Sat, 20 Aug 2011 15:29:11 +0100

This study evaluated color alteration and changes in microhardness of a microhybrid composite after immersion in different colored foods and determined whether there was a correlation between these two variables. Eighty composite disks were randomly divided into 8 experimental groups (n = 10): kept dry; deionized water; orange juice; passion fruit juice; grape juice; ketchup; mustard and soy sauce. The disks were individually immersed in their respective test substance at 37 ºC, for a period of 28 days. Superficial analysis of the disk specimens was performed by taking microhardness measurements (Vickers, 50 g load for 45 seconds) and color alterations were determined with a spectrophotometer (CINTRA 10- using a CIEL*a*b* system, 400-700 nm wavelength, illuminant d65 and standard observer...

Comparison between cone-beam and multislice computed tomography for identification of simulated bone lesions

Brazilian Oral Research — Sat, 20 Aug 2011 15:29:11 +0100

There are many studies that compare the accuracy of multislice (MSCT) and cone beam (CBCT) computed tomography for evaluations in the maxillofacial region. However, further studies comparing both acquisition techniques for the evaluation of simulated mandibular bone lesions are needed. The aim of this study was to compare the accuracy of MSCT and CBCT in the diagnosis of simulated mandibular bone lesions by means of cross sectional images and axial/MPR slices. Lesions with different dimensions, shape and locularity were produced in 15 dry mandibles. The images were obtained following the cross sectional and axial/MPR (Multiplanar Reconstruction) imaging protocols and were interpreted independently. CBCT and MSCT showed similar results in depicting the percentage of cortical bone involvemen...

Influence of the casting material on the dimensional accuracy of dental dies

Brazilian Oral Research — Sat, 20 Aug 2011 15:29:11 +0100

The purpose of this study was to evaluate the dimensional accuracy of different materials used in the confection of dies. Two stainless steel standard models were confected. One of the models, which was 2 mm larger than the other model, was used to provide a uniform relief for the two-step putty-wash impression technique. Thirty impressions were obtained using a polyvinyl siloxane impression material and randomly divided into three groups (n = 10) according to the type of casting material: type IV dental stone, commercially available epoxy resin (Tri-Epoxy), and industrial epoxy resin (Sikadur). After the setting/polymerization of the casting material, the dimensional stability was measured in terms of the height, diameter of the base and diameter of the top from the obtained dies and from...

Effect of hyposalivation on mastication and mandibular movements during speech

Brazilian Oral Research — Sat, 20 Aug 2011 15:29:11 +0100

The aim of this study was to evaluate whether patients with hyposalivation present damaged mastication or mandibular movements during speech. Forty subjects composed 2 groups: control and hyposalivation. Masticatory performance was assessed with a silicon-based artificial material and a 10-sieve method. Mandibular movements during speech were observed with a 3D jaw-tracking device. Data were analyzed with Student's t-test or the Mann-Whitney method (P < 0.05). The masticatory performance (mm) of control and hyposalivation were 4.40 ± 0.62 and 4.74 ± 1.34, respectively. Outcomes for speech movements (mm) were as follows: maximum vertical opening amplitude (10.8 ± 4.2; 9.9 ± 2.7) and displacements to the right (1.0 ± 0.8; 0.5 ± 0.6), left (1.8 ± 1.4; 2.3 ± 1.2), or anterior-posterior...

Influence of remaining coronal structure and finish line on the fracture strength of roots restored with metallic posts

Brazilian Oral Research — Sat, 20 Aug 2011 15:29:11 +0100

The purpose of this study was to evaluate the fracture strength of roots that were prosthetically restored with metallic posts with or without any remaining coronal structure and with different finish lines. Sixty bovine incisors were sectioned below the cementoenamel junction, endodontically treated, and randomly divided into six experimental groups (n = 10) containing teeth with or without any remaining coronal structure, and with a beveled shoulder, a bevel, or a shoulder finish line design. The metallic posts were luted with dual-cured resin cement. The cores were made with composite resin, and metal crowns were cemented with zinc phosphate cement. The specimens were subjected to a tangential compressive load (135º angle) at a crosshead speed of 0.5 mm/min until failure, using a unive...

Comparative efficacy of two daily use mouthrinses: randomized clinical trial using an experimental gingivitis model

Brazilian Oral Research — Sat, 20 Aug 2011 15:29:11 +0100

This study demonstrates that the essential oil-containing mouthrinse has superior antiplaque/antigingivitis effectiveness compared to the 0.07% CPC-containing mouthrinse without mechanical oral hygiene influence. (Source: Brazilian Oral Research)

Bottle feeding, increased overjet and Class 2 primary canine relationship: is there any association?

Brazilian Oral Research — Sat, 20 Aug 2011 15:29:11 +0100

The aim of this study was to investigate the association between bottle feeding and prevalence rates of increased overjet and Class 2 primary canine relationship. The sample consisted of 911 children (461 boys, 450 girls) aged 3 (13.9%), 4 (40.8%), 5 (34%) and 6 (11.3%) years, with complete primary dentition. Information about nutritive and nonnutritive (pacifier and/or digit) sucking habits was collected through questionnaires. Three calibrated dentists (κ: 0.9-1.0 and Rs > 0.90) performed the clinical assessments. The children were divided into four groups: G1 - not bottle-fed; G2 - exclusively bottle-fed; G3 - breast- and bottle-fed, bottle feeding ceased before 3 years of age; and G4 - breast- and bottle-fed, bottle feeding ceased between 3 and 4 years of age. Associations between ...

Crown dimensions and proximal enamel thickness of mandibular second bicuspids

Brazilian Oral Research — Sat, 20 Aug 2011 15:29:11 +0100

This study aimed at evaluating crown dimensions and proximal enamel thickness in a sample of 40 extracted sound, human, mandibular, second bicuspids (20 right and 20 left). Mesiodistal, cervico-occlusal and buccolingual crown dimensions were measured using a digital caliper, accurate to 0.01 mm. Teeth were embedded in acrylic resin and cut along their long axes through the proximal surfaces to obtain 0.7 mm-thick central sections. Enamel thickness on the cut sections was measured using a perfilometer. Comparative analyses were carried out using the Student's-t test (α= 5%). The mean mesiodistal crown widths for right and left teeth were 7.79 mm (± 0.47) and 7.70 mm (± 0.51), respectively. Mean cervico-occlusal heights ranged from 8.31 mm (± 0.75) on the right to 8.38 mm (± 0.85) on th...

Dental trauma in individuals with severe cerebral palsy: prevalence and associated factors

Brazilian Oral Research — Sat, 20 Aug 2011 15:29:11 +0100

The aim of the present study was to determine the prevalence of dental trauma and associated factors among a sample of patients with severe cerebral palsy. The sample was made up of 120 individuals equally divided into two groups. The group with cerebral palsy was made up of 60 patients diagnosed with the spastic form of the disease. The control group was made up of 60 individuals with no mental impairment. Questionnaires were used to collect information on individual, socioeconomic and behavioral characteristics. Dental trauma was assessed based on the clinical chart of each participant, on a questionnaire and on a clinical evaluation to determine past injuries. Mouth mirrors and millimeter periodontal probes (Community Periodontal Index probe) were used to measure overjet. Lip seal and b...

Influence of Hero Apical instruments on cleaning ovoid-shaped root canals

Brazilian Oral Research — Sat, 20 Aug 2011 15:29:11 +0100

The cleaning capacity of Hero 642 nickel-titanium files, complemented by the Hero Apical instruments in flattened roots, was determined by histological analysis, considering the area of action of the instruments on the coronal walls and the presence of remaining debris. Twenty-four single-canal, human mandibular incisors were divided into three groups and prepared as follows: GI, instrumented with Hero 642 NiTi files 30/.06, 25/.06, 20/.06, 25/.06, and 30/.06; GII, instrumented as GI followed by Hero Apical size 30/.06; GIII, instrumented as GI followed by Hero Apical sizes 30/.06 and 30/.08, then returning to 30/.06 with pendulum movements. The apical thirds were prepared for histological processing, analyzed at 40× magnification and the images were examined morphometrically. Statistical...

Dentists' level of knowledge of the treatment plans for periodontal ligament injuries after dentoalveolar trauma

Brazilian Oral Research — Sat, 20 Aug 2011 15:29:11 +0100

This study investigated the level of knowledge held by dentists about the possible treatment plan procedures for periodontal ligament injuries after dentoalveolar trauma. A 5-item self-applied questionnaire was prepared with questions referring to the professional profile of the interviewees and to the treatment plan they would propose for periodontal ligament injuries secondary to dentoalveolar trauma. The questionnaires were filled out by 693 dentists attending the 23rd Annual Meeting of the Brazilian Society for Dental Research, and the data obtained were subjected to descriptive analysis. Either the chi-square test or Fisher's exact test was applied to assess associations among variables, at a 5% level of significance. The results revealed that dentists experienced difficulty in establ...

Photoelastic analysis of stress generated by a silorane-based restoration system

Brazilian Oral Research — Sat, 20 Aug 2011 15:29:11 +0100

Silorane-based composite, an epoxy material, was marketed as promising less polymerization contraction than conventional restorative materials. The aim of this study was to evaluate, by means of photoelasticity, the polymerization stress generated by a silorane-based composite. Thirty photoelastic rings with orifices measuring 5 mm (d) × 3 mm (h) were prepared and divided into 6 groups (n = 5) according to the material tested. The inside walls of the rings were sandblasted with aluminum oxide, after which the restorative materials were inserted into the orifices and photoactivated according to the manufacturer's instructions. The specimens were analyzed and the visual representation of the stress was measured considering the isochromatic ring of first order. The data were converted to MPa...

Microtensile bond strength of quartz fiber posts to different composite cores

Brazilian Oral Research — Sat, 20 Aug 2011 15:29:11 +0100

The aim of this in vitro study was to assess the microtensile bond strength of quartz fiber posts to different composites, and to composite combinations used as core materials. Thirty fiber posts were treated with a 24% hydrogen peroxide solution and silanized. The posts were divided into 5 groups according to the resin composite used as follows (n = 6): G1 - Ælite Flow (Bisco, Inc), G2 - Filtek Z250 (3M ESPE), G3 - Biscore (Bisco, Inc), G4 - Ælite Flow + Filtek Z250, G5 - Ælite Flow + Biscore. The resin composites were placed around the posts to produce cylindrical specimens. Two 1-mm² thick sticks containing the post in the center and composite cores on both ends were provided from each cylinder and tested for microtensile strength with a crosshead speed of 0.5 mm/min. One-way ANOVA ...

Physical-chemical characteristics of whitening toothpaste and evaluation of its effects on enamel roughness

Brazilian Oral Research — Sat, 20 Aug 2011 15:29:11 +0100

This in vitro study evaluated the physical-chemical characteristics of whitening toothpastes and their effect on bovine enamel after application of a bleaching agent (16% carbamide peroxide). Physical-chemical analysis was made considering mass loss by desiccation, ash content and pH of the toothpastes. Thirty bovine dental enamel fragments were prepared for roughness measurements. The samples were subjected to bleaching treatments and simulated brushing: G1. Sorriso Dentes Brancos (Conventional toothpaste), G2. Close-UP Whitening (Whitening toothpaste), and G3. Sensodyne Branqueador (Whitening toothpaste). The average roughness (Ra) was evaluated prior to the bleaching treatment and after brushing. The results revealed differences in the physical-chemical characteristics of the toothpaste...

Challenges faced by the stricto sensu graduate programs

Brazilian Oral Research — Sat, 20 Aug 2011 15:29:11 +0100

(Source: Brazilian Oral Research)

Micromorphological and hardness analyses of human and bovine sclerotic dentin: a comparative study

Brazilian Oral Research — Mon, 13 Jun 2011 15:56:46 +0100

The purpose of this study was to test the hypothesis that both human and bovine sclerotic dentin have similar hardness properties, in addition to similar micromorphological characteristics. Sixteen teeth (8 human and 8 bovine) exhibiting exposed dentin in the incisal edge and showing characteristics typical of sclerosis were used. Vickers surface microhardness testing was conducted. Three areas of the dentin surface of each specimen were selected. All teeth were processed for scanning electron microscopy in order to estimate the amount (in percentage) of solid dentin on the sclerotic dentin surface. The data were compared by Student's t test (α = 0.05). The micromorphological and microhardness data were compared by Pearson's linear correlation test (α = 0.05). The mean percentages of sol...

Knoop microhardness and FT-Raman evaluation of composite resins: influence of opacity and photoactivation source

Brazilian Oral Research — Mon, 13 Jun 2011 15:56:46 +0100

The aim of this study was to evaluate the degree of conversion by Knoop microhardness (KHN) and FT-Raman spectroscopy (FTIR) of one nanofilled (Filtek Supreme-3M-ESPE [FS]) and one microhybrid composite (Charisma-Heraeus-Kulzer [CH]), each with different opacities, namely enamel, dentin, and translucent, which were photo-activated by a quartz-tungsten-halogen lamp (QTH) and a light-emitting diode (LED). Resin was bulk inserted into a disc-shaped mold that was 2.0 mm thick and 4 mm in diameter, obtaining 10 samples per group. KHN and FTIR values were analyzed by two-way ANOVA and Tukey's tests (α = 0.05). Nanofilled resin activated by a LED presented higher microhardness values than samples activated by a QTH for dentin opacity (p < 0.05). The microhybrid resin showed no differences in KHN...

Influence of marginal fit and cement types on microleakage of all-ceramic crown systems

Brazilian Oral Research — Mon, 13 Jun 2011 15:56:46 +0100

The purpose of this study was to evaluate the effects of both marginal fit and cementing with different luting agents on the microleakage of all-ceramic crown systems. Thirty-six extracted upper central incisors were prepared for full-coverage crowns and were divided into three groups. Group 1: CAD/CAM-fabricated ZrO2, Group 2: Heat-pressed lithium-disilicate, and Group 3: Cast Cr-Co copings as the control group. Copings were made following standard techniques, and groups were assigned cementation with either self-adhesive resin cement (A) or glass-ionomer luting cement (B). The specimens were subjected to thermocycling, immersed in basic fuchsin solution, sectioned mesiodistally and buccolingually. The surface of each section was digitally photographed under a stereomicroscope. Microleaka...

Langerhans cells in periodontal disease of HIV- and HIV+ patients undergoing highly active antiretroviral therapy

Brazilian Oral Research — Mon, 13 Jun 2011 15:56:46 +0100

In conclusion, the use of HAART can aid in achieving viral loads, and it is suggested that it may prevent the destruction of the LC. (Source: Brazilian Oral Research)

Obstetricians' knowledge of periodontal disease as a potential risk factor for preterm delivery and low birth weight

Brazilian Oral Research — Mon, 13 Jun 2011 15:56:46 +0100

This study aimed to assess the knowledge and attitudes of obstetricians about the relationship between periodontal disease and preterm/low birth weight. A questionnaire was emailed to members of the Brazilian Federation of Gynecology and Obstetrics (FEBRASGO). The questionnaire elicited both personal information and knowledge and attitudes regarding the relationship between periodontal diseases and preterm labor. A total of 875 obstetricians responded to the questionnaire. The majority of respondents were female (54.1%), resided in the Southeast (45.6%), worked in both the public and private sectors (61.4%), and had over 15 years of experience in obstetrics (48.9%). A large proportion of obstetricians (93.4%) stated that bacteria were associated with periodontal disease, and 94% reported t...

Effects of age and gender on upper airway, lower airway and upper lip growth

Brazilian Oral Research — Mon, 13 Jun 2011 15:56:46 +0100

In this study, 390 lateral cephalograms were divided into 13 age groups (ranging from 6 to 18 years) and were analyzed. The intergroup differences were analyzed using a MANOVA (Multivariate Analysis of the Variance), and the intragroup differences were analyzed using an ANOVA (Analysis of the Variance) and Tukey's test. The results of the present study indicated that although the airway width and the upper lip length increased with age, the lower airway width exhibited variable growth between the ages of six and eighteen years. The airway width was significantly greater in females than males, whereas the upper airway width was similar between these two genders. The lip length was significantly shorter in females than males. The lower airway width and upper lip length were significantly dif...

Vimentin expression and the influence of Matrigel in cell lines of head and neck squamous cell carcinoma

Brazilian Oral Research — Mon, 13 Jun 2011 15:56:46 +0100

Vimentin is a cytoeskeletal intermediate filament protein commonly observed in mesenchymal cells; however, it can also be found in malignant epithelial cells. It is demonstrated in several carcinomas, such as those of the cervix, breast and bladder, in which it is widely used as a marker of the epithelial to mesenchymal transition that takes place during embryogenesis and metastasis. Vimentin is associated with tumors that show a high degree of invasiveness, being detected in invasion front cells. Its expression seems to be influenced by the tumor microenvironment. The aim of this study was to evaluate vimentin expression in head and neck squamous cell carcinoma (HNSCC) cell lines, and to investigate the contribution of the microenvironment to its expression. HNSCC cell lines (HN6, HN30 an...

Effect of photodynamic therapy on clinical isolates of Staphylococcus spp

Brazilian Oral Research — Mon, 13 Jun 2011 15:56:46 +0100

The objective of this study was to evaluate the effect of photodynamic therapy (PDT) on 20 Staphylococcus strains isolated from the human oral cavity, including S. aureus, S. schleiferi, S. epidermidis, S. capitis, S. haemolyticus, and S. lentus. A suspension of each Staphylococcus strain (10(6) cells/mL) was submitted to PDT using methylene blue and a low power laser. The isolated effects of methylene blue, laser treatment and ciprofloxacin were also evaluated. After the experimental treatments, 0.1 mL aliquots of the suspensions were seeded onto BHI agar for determination of the number of colony-forming units (CFU/mL). The results were analyzed by analysis of variance and Tukey's test (p < 0.05). The mean reduction in bacterial counts of the strains submitted to PDT ranged from 4.89 to 6...

Age estimation of indian adults from orthopantomographs

Brazilian Oral Research — Mon, 13 Jun 2011 15:56:46 +0100

In conclusion there is a linear relationship of pulp/root width ratio at mid-root level and pulp/tooth area ratio of the right maxillary canine with chronological age in the Indian population. Age of subjects can therefore be estimated with a good degree of accuracy using regression equations. (Source: Brazilian Oral Research)

Experimental model of distraction osteogenesis in edentulous rats

Brazilian Oral Research — Mon, 13 Jun 2011 15:56:46 +0100

Distraction osteogenesis (DO) is a surgical technique producing bone lengthening by distraction of the fracture callus. Although a large number of experimental studies on the events associated with DO of craniofacial skeleton have been reported, the few employing rat mandibular bone DO used complicated designs and produced a small volume of newly formed bone. Thus, this study aims to present an original experimental model of mandibular DO in edentulous rats that produces a sufficient quantity and quality of intramembranous bone. Eight male Wistar rats, weighing 75 g, underwent extraction of lower molars. With rats weighing 350 g, right mandibular osteotomy was performed and the distraction device was placed. The distraction device was custom made using micro-implants, expansion screws, and...

Study of the morpho-dimensional relationship between the maxillary central incisors and the face

Brazilian Oral Research — Mon, 13 Jun 2011 15:56:46 +0100

The aim of this study was to evaluate the frequency of agreement between the shape of the maxillary central incisor (MCI) and that of the face; verify which is the most pleasing MCI shape for the two genders; whether there is coincidence in the preference for tooth shape; and measure the most pleasant proportion of tooth and facial width for the esthetics of the smile. One hundred patients were selected from among front view photographs of the face and smile. The photographs were evaluated to determine the shape of the face and the type of dental contour, the pleasant appearance of the set consisting of the teeth and facial features. The widths of the MCIs and the face were measured and the proportional values were associated with the evaluators' opinions with regard to the pleasant appear...

Effectiveness of gutta-percha and Resilon in filling lateral root canals using the Obtura II system

Brazilian Oral Research — Mon, 13 Jun 2011 15:56:46 +0100

In conclusion, Resilon and EndoFlow gutta-percha were effective in filling lateral canals by using the Obtura II system. (Source: Brazilian Oral Research)

A map of Brazilian dental research in the last decade

Brazilian Oral Research — Mon, 13 Jun 2011 15:56:46 +0100

The aim of the present study was to analyze dental research trends in Brazil over the past nine years. All abstracts presented at the 26th Annual Meeting of the Brazilian Society for Dental Research in 2009 (n = 2648) were classified based on field of knowledge, home institution and geographic region. Data were compared with those previously published based on abstracts presented at various meetings. Between 2001 and 2006, five fields of knowledge had a greater than 10% representation among the total number of studies. These fields included restorative dentistry/dental materials (RD/DM), periodontics, endodontics, pediatric dentistry and population-based oral health. In 2009, only RD/DM maintained a greater than 10% proportion of meeting abstracts, and basic fields comprised the second pos...

Editorial - an unmissable chance

Brazilian Oral Research — Mon, 13 Jun 2011 15:56:46 +0100

(Source: Brazilian Oral Research)

Fine needle aspiration biopsy in the oral cavity and head and neck region

Brazilian Oral Research — Sat, 30 Apr 2011 17:54:48 +0100

The objective of the current study was to evaluate the sensitivity, specificity and accuracy of fine needle aspiration biopsy (FNAB) of submucous nodules from the oral cavity and head and neck region as an auxiliary diagnostic tool. Fifty patients with nodule lesions in the oral cavity and the head and neck region were selected. All of them were submitted to FNAB and to either incisional or excisional biopsy. The diagnoses from the FNABs were compared with the biopsy diagnosis as the gold standard. All the cases of FNAB were analyzed by a single oral pathologist prior to the biopsy diagnosis. The results showed that the sensitivity of FNAB was 75%, its specificity was 96% and its accuracy was 58.8%. The false positive and false negative rates were 6.7% and 13.3%, respectively. The positive...

Acupuncture for the prevention of radiation-induced xerostomia in patients with head and neck cancer

Brazilian Oral Research — Sat, 30 Apr 2011 17:54:48 +0100

The aim of this study was to evaluate the effectiveness of acupuncture in minimizing the severity of radiation-induced xerostomia in patients with head and neck cancer. A total of 24 consecutive patients receiving > 5000 cGy radiotherapy (RT) involving the major salivary glands bilaterally were assigned to either the preventive acupuncture group (PA, n = 12), treated with acupuncture before and during RT, or the control group (CT, n = 12), treated with RT and not receiving acupuncture. After RT completion, clinical response was assessed in all patients by syalometry, measuring the resting (RSFR) and stimulated (SSFR) salivary flow rates, and by the visual analogue scale (VAS) regarding dry mouth-related symptoms. Statistical analyses were performed with repeated-measures using a mixed-e...

Pre-heated dual-cured resin cements: analysis of the degree of conversion and ultimate tensile strength

Brazilian Oral Research — Sat, 30 Apr 2011 17:54:48 +0100

This study evaluated the degree of conversion (DC) and ultimate tensile strength (UTS) of dual-cured resin cements heated to 50º C prior to and during polymerization. Disc- and hourglass-shaped specimens of Rely X ARC (RX) and Variolink II (VII) were obtained using addition silicon molds. The products were manipulated at 25º C or 50º C and were subjected to 3 curing conditions: light-activation through a glass slide or through a pre-cured 2-mm thick resin composite disc, or they were allowed to self-cure (SC). All specimens were dark-stored dry for 15 days. For DC analysis, the resin cements were placed into the mold located on the center of a horizontal diamond on the attenuated total reflectance element in the optical bench of a Fourier Transformed Infrared spectrometer. Infrared spec...

Effects of mouthwashes on Knoop hardness and surface roughness of dental composites after different immersion times

Brazilian Oral Research — Sat, 30 Apr 2011 17:54:48 +0100

The aim of this in vitro study was to evaluate the effect of different mouthwashes on superficial roughness and Knoop hardness of two resin composites. Eighty specimens (6 mm Ø and 2 mm height) were prepared and divided into eight experimental groups (n = 10) according to the resin composites (4 Seasons and Esthet X), and storage solutions (G1 - Distilled water; G2 - Colgate Plax Overnight; G3 - Colgate Plax Alcohol Free; and G4 - Colgate Plax Whitening). The initial hardness and roughness readings (T1) were measured and then the specimens were stored in 2 mL of mouthwash for 12 h (T2) and 24 h (T3). The data were analyzed with repeat-measures two-way ANOVA and Tukey's test (α = 5%). Regardless of the type of solution and time of exposure, there was no statistical difference for roughnes...

Evaluation of the accuracy of different transfer impression techniques for multiple implants

Brazilian Oral Research — Sat, 30 Apr 2011 17:54:48 +0100

The aim of this study was to evaluate the accuracy of three implant transfer impression techniques. Four groups (n = 5) were defined, according to the technique: TC - tapered copings without splint; SC - square copings without splint; SCS - square copings splinted with dental floss and acrylic resin, and CG (control group) - master model with four external hexagonal implants and a superstructure. Individual trays and polyether were used for the impression. All casts were checked for their fit into the master superstructure; for this, all four screws were placed in the implants. Digital photos were taken and images were analyzed using UTHSCSA ImageTool software. Statistical analyses were performed using one-way analysis of variance and Studentâs t test (p < 0.05). The means and standar...

Periodontal ligament and gingival fibroblasts participate in the production of TGF-β, interleukin (IL)-8 and IL-10

Brazilian Oral Research — Sat, 30 Apr 2011 17:54:48 +0100

The aim of this study was to quantify and compare the production of transforming growth factor beta (TGF-β), interleukin (IL)-8 and IL-10 by human cultured periodontal ligament and gingival fibroblasts both obtained from the same donors challenged with lipopolysaccharide (LPS) from Porphyromonas gingivalis. Fibroblasts were exposed to 0.1-10 µg/mL of LPS from P. gingivalis and after 24 h the supernatants were collected and analyzed by enzyme-linked immunosorbent assay (ELISA). TGF-β protein production was upregulated in a concentration-dependent manner, mainly in gingival fibroblasts, which was statistically significant when challenged by 10 µg/mL LPS. Additionally, at this concentration, gingival fibroblasts had almost a two-fold increase in the amount of TGF-β when compared to perio...

Luxation injuries in primary teeth: a retrospective study in children assisted at an emergency service

Brazilian Oral Research — Sat, 30 Apr 2011 17:54:48 +0100

In conclusion, more luxation injuries were found in younger children, predominantly in boys. Falls resulting from walking or running were the etiologic factor most observed, with subluxation as the most common type of trauma. Treatment usually occurred within the first 15 days after the injury. Despite the severity of these injuries, "monitor only" was the eligible treatment. (Source: Brazilian Oral Research)

Influence of self-perceived oral health and socioeconomic predictors on the utilization of dental care services by schoolchildren

Brazilian Oral Research — Sat, 30 Apr 2011 17:54:48 +0100

This study followed a cross-sectional design, with a multistage random sample of 792 12-year-old schoolchildren from Santa Maria, a city in southern Brazil. A dental examination provided information on the prevalence of dental caries (DMFT index). Data about the use of dental service, socioeconomic status, and self-perceived oral health were collected by means of structured interviews. These associations were assessed using Poisson regression models (prevalence ratio; 95% confidence interval). The prevalence of regular use of dental service was 47.8%. Children from low socioeconomic backgrounds and those who rated their oral health as "poor" used the service less frequently. The distribution of the kind of oral healthcare assistance used (public/private) varied across socioeconomic groups....

Effect of irradiation times on the polymerization depth of contemporary fissure sealants with different opacities

Brazilian Oral Research — Sat, 30 Apr 2011 17:54:48 +0100

The aim of this study was to evaluate the depth of curing of 10 contemporary blue light-activated dental flowable materials at several opacities, influenced by different irradiation times using FT-IR spectroscopy. Fifty-five specimens (n = 5) with a 5-mm diameter and 1-mm thickness of translucent (Opallis Flow T), yellowed (Master Flow A2; Opallis Flow A2; Natural Flow A2; Fluroshield Yellowed), and opaque materials (Master Flow OA2; Natural Flow O; Opallis Flow OA3.5; Opallis Flow OP; Fluroshield White) were obtained at six curing times (10s, 20s, 30s, 40s, 50s, and 60s) using a high-intensity LED (Coltolux, ColtÃ¨ne/Whaledent). The degree of conversion (DC) (%) was obtained using the Nexus 470 FTIR Spectrometer (Nicolet Instruments, USA). The FTIR-ATR spectra for uncured and cured samp...

Effect of heat treatment on stainless steel orthodontic wires

Brazilian Oral Research — Sat, 30 Apr 2011 17:54:48 +0100

This study evaluated the effect of heat treatment on CrNi stainless steel orthodontic archwires. Half of forty archwires of each thickness - 0.014" (0.35 mm), 0.016" (0.40 mm), 0.018" (0.45 mm) and 0.020" (0.50 mm) (totalling 160 archwires) - were subjected to heat treatment while the remainder were not. All of the archwires had their individual thickness measured in the anterior and posterior regions using AutoCad 2000 software before and after compressive and tensile strength testing. The data was statistically analysed utilising multivariance ANOVA at a 5% significance level. All archwires without heat treatment that were subjected to tensile strength testing presented with anterior opening, which was more accentuated in the 0.020" archwires. In the posterior region, the opening produce...

Comprehensive intermaxillary tooth width proportion of Bangkok residents

Brazilian Oral Research — Sat, 30 Apr 2011 17:54:48 +0100

The objective of this study was to measure tooth size disproportion for Thai patients and to calculate a corresponding set of CPRs. Thirty-seven pairs of dental models were made from a group of Bangkok residents with normal occlusion. Mesiodistal tooth width was measured for each model. The intra- and inter-examiner measurement errors were ascertained as insignificant (p > 0.05). CPRs were then calculated and compared to those derived from other studies. Ten of thirteen CPRs were significantly different from corresponding values derived from Caucasians. We conclude that tooth width ratios vary between different racial groups, and therefore that these should be calculated specifically for each patient racial group. (Source: Brazilian Oral Research)

Comparison of the fracture torque of different Brazilian mini-implants

Brazilian Oral Research — Sat, 30 Apr 2011 17:54:48 +0100

This study evaluated fracture torque by torsion, in relation to the length and diameter of orthodontic mini-implants, to demonstrate their viability for clinical and experimental use based on the torque recommended by the manufacturers. The fractures at the moment of insertion, whose incidence in the literature is around 4%, are principally due to excessive force and the inability of the implant to resist rotational forces. Thirty orthodontic mini-implants of three commercial brands available in Brazil (Neodent 1.6 x 9 mm, Dentoflex 1.6 x 9 mm and Kopp 1.6 x 9 mm) were attached to a device made specifically for this research, leaving the mini-implants with sufficient stability. The miniimplants were submitted to torsion torque, using a digital torque wrench, until their breaking point. The...

Shear bond strength of self-etch and total-etch bonding systems at different dentin depths

Brazilian Oral Research — Sat, 30 Apr 2011 17:54:48 +0100

The purpose of this study was to evaluate the dentin shear bond strength of four adhesive systems (Adper Single Bond 2, Adper Prompt L-Pop, Magic Bond DE and Self Etch Bond) in regards to buccal and lingual surfaces and dentin depth. Forty extracted third molars had roots removed and crowns bisected in the mesiodistal direction. The buccal and lingual surfaces were fixed in a PVC/acrylic resin ring and were divided into buccal and lingual groups assigned to each selected adhesive. The same specimens prepared for the evaluation of superficial dentin shear resistance were used to evaluate the different depths of dentin. The specimens were identified and abraded at depths of 0.5, 1.0, 1.5 and 2.0 mm. Each depth was evaluated by ISO TR 11405 using an EMIC-2000 machine regulated at 0.5 mm/min w...

Radiographic inspection of porosity in Ti-6Al-4V laser-welded joints

Brazilian Oral Research — Sat, 30 Apr 2011 17:54:48 +0100

This study was conducted to evaluate the effect of joint openings and diameters of laser-welded joints executed in Ti-6Al-4V structures on the presence of pores as checked by radiographic procedures. Sixty dumbbell rods with central diameters of 1.5, 2.0 and 3.5 mm were created from Ti-6Al-4V-wrought bars. Specimens were sectioned and welded using two joint openings (0.0 and 0.6 mm). The combination of variables created six groups (n = 10). Laser welding was executed using 360V/8ms (1.5 and 2.0 mm) and 380V/9ms (3.5 mm), with the focus and frequency set to zero. The joints were finished, polished and submitted to radiographic examination. The radiographs were visually examined for the presence of pores in the joints, qualitatively. The percentage of radiographic presence of pores was calcu...

Plagiarism in scientific publication

Brazilian Oral Research — Sat, 30 Apr 2011 17:54:48 +0100

(Source: Brazilian Oral Research)

Allergic reactions and nickel-free braces: a systematic review

Brazilian Oral Research — Sun, 27 Feb 2011 17:49:55 +0100

Nickel-free braces have gained popularity as a viable alternative for patients who are allergic to nickel. The purpose of this systematic review was to determine whether evidence exists to justify the use of nickel-free brackets in orthodontic patients who are allergic to nickel. An electronic search was performed using 7 databases (MEDLINE, BBO, LILACS, Web of Science, EMBASE, BIREME and Cochrane Library), without restriction regarding year or language, with supplemental manual searching of the references of retrieved articles. The search strategy produced 89 papers. The data extraction and quality score of each paper were evaluated independently by two reviewers, once each. After selection based on the eligibility criteria, four papers, including 2 controlled clinical trials and 2 clinic...

Comparison of two methods for alveolar bone loss measurement in an experimental periodontal disease model in rats

Brazilian Oral Research — Sun, 27 Feb 2011 17:49:55 +0100

There are many studies that evaluate possible risk factors for periodontal diseases in animals. Most of them have focused only on the biological aspects of disease occurrence; therefore, it has been difficult to compare studies of the different methodological approaches. The aim of the present study was to compare different methods - linear and area - of the evaluation of morphometrical alveolar bone loss. Sixty hemimaxillae, defleshed and stained with 1% methylene blue to delineate the cementoenamel junction and alveolar bone crest, were obtained from a previous study that induced periodontal disease by means of ligatures in two groups of fifteen Wistar rats during 9 weeks. Ligatures were placed around the right upper second molars, and the contra-lateral teeth remained as intra-group con...

Supernumerary teeth vary depending on gender

Brazilian Oral Research — Sun, 27 Feb 2011 17:49:55 +0100

In conclusion, ST patterns vary depending on gender. (Source: Brazilian Oral Research)

Inequalities in the distribution of dental caries among 12-year-old Brazilian schoolchildren

Brazilian Oral Research — Sun, 27 Feb 2011 17:49:55 +0100

This study followed a cross-sectional design, with a sample of 792 schoolchildren aged 12 years, representative of this age group in Santa Maria, RS, Brazil. Guardians answered questions on socioeconomic status and a dental examination provided information on the dental caries experience (DMF-T). Inequality in dental caries distribution was measured by the Gini coefficient and the Significant Caries Index (SiC). The assessment of association used Poisson regression models. Socioeconomic factors were associated with prevalence of dental caries for the whole sample and also for individuals with a high-caries level. Children from low-income households had the highest prevalence of dental caries. The Gini coefficient was 0.7 and the SiC Index 2.5. The percentage of caries prevalence was 39.3% ...

Mechanical evaluation of space closure loops in Orthodontics

Brazilian Oral Research — Sun, 27 Feb 2011 17:49:55 +0100

This study evaluated the mechanical performance of teardrop-shaped loops and teardrop-shaped loops with helix used in orthodontic space closure. Sixty retraction loops made with 0.019" x 0.025" stainless steel (SS) and beta-titanium (BT) wires were used. They were attached to a testing machine to measure the magnitudes of the sagittal force and the load-deflection ratio necessary for 1 mm, 2 mm and 3 mm activation. The results demonstrated that the BT alloy presented significantly smaller mean values (p < 0.01) of sagittal force and load-deflection than the SS alloy. The loop with the highest mean value of sagittal force and load-deflection was the teardrop-shaped loop (p < 0.01). Differences were observed in the mean values of sagittal force and load-deflection among activations, and the ...

Correlations between dentoskeletal variables and deep bite in Class II Division 1 individuals

Brazilian Oral Research — Sun, 27 Feb 2011 17:49:55 +0100

This study aimed to evaluate the cephalometric pattern of Class II Division 1 individuals with deep bite, and to determine possible correlations between dentoskeletal variables and deep bite. Comparisons were also made between genders and cases that were to be treated both with and without premolar extraction. A total of 70 lateral cephalograms were used, from both male (n = 35) and female (n = 35) individuals with an average age of 11.6 years, who simultaneously presented with ANB > 5º and overbite > 4 mm. Statistical analysis involved parametric (t-test) and non-parametric (Mann-Whitney) tests for independent samples, as well as the Spearman correlation test (p < 0.05). The values of Go-Me, Ar-Pog, PM-1 and PM-CMI were higher in males (p < 0.05). However, no significant difference...

Comparative in vitro study of the shear bond strength of brackets bonded with restorative and orthodontic resins

Brazilian Oral Research — Sun, 27 Feb 2011 17:49:55 +0100

The aim of this study was to evaluate the shear bond strength of brackets bonded with different restorative systems and compare it with that afforded by an established orthodontic bonding system. Seventy human bicuspids were used, divided into five different groups with 14 teeth each. Whereas a specific orthodontic bonding resin (TransbondTM XT) was used in the control group, the restorative systems Charisma, Tetric Ceram, TPH Spectrum and Z100 were used in the other four groups. Seven days after bonding the brackets to the samples, shear forces were applied under pressure in a universal testing machine. The data collected was evaluated using the ANOVA test and, when a difference was identified, the Tukey test was applied. A 5% level of significance was adopted. The mean results of the she...

Influence of the association between simvastatin and demineralized bovine bone matrix on bone repair in rats

Brazilian Oral Research — Sun, 27 Feb 2011 17:49:55 +0100

Simvastatin, a drug used to lower blood cholesterol, has been reported to have an anabolic effect on bone. The purpose of this study was to evaluate the influence of simvastatin and demineralized bovine bone matrix (DBBM) on the repair of rat calvarial defects. Defects of 5 mm were created in 64 rats, divided into four groups: no local treatment (control); treatment with DBBM (DBBM); treatment with a combination of simvastatin solution (2.2 mg/50 μl) and DBBM (DBBMSIM-1); and treatment with simvastatin solution (0.5 mg/50 μl) and DBBM (DBBMSIM-2). Animals were sacrificed on postoperative day 30 or 60, after which the calvariae were X-rayed and prepared for histomorphometric evaluation. The data were submitted to statistical analysis (p < 0.05). X-rays revealed that, on postoperative day ...

Immunohistochemical expression of p53, p16 and hTERT in oral squamous cell carcinoma and potentially malignant disorders

Brazilian Oral Research — Sun, 27 Feb 2011 17:49:55 +0100

The objective of this study was to use immunohistochemistry to analyze the patterns of expression of the cell-cycle regulatory proteins p53 and p16INK4a in potentially malignant disorders (PMD) of the oral mucosa (with varying degrees of dysplasia) and in oral squamous cell carcinomas (OSCC) to correlate them with the expression of telomerase (hTERT). Fifteen PMD and 30 OSCC tissue samples were analyzed. Additionally, 5 cases of oral epithelial hyperplasia (OEH) were added to analyze clinically altered mucosa presenting as histological hyperplasia without dysplasia. p53 positivity was observed in 93.3% of PMD, in 63.3% of OSCC and in 80% of OEH. Although there was no correlation between p53 expression and the grade of dysplasia, all cases with severe dysplasia presented p53 suprabasal immu...

In vitro antifungal susceptibility of Candida spp. oral isolates from HIV-positive patients and control individuals

Brazilian Oral Research — Sun, 27 Feb 2011 17:49:55 +0100

Oropharyngeal candidiasis is the most common fungal infection among HIV-positive patients. This condition can be treated with either systemic or topical antifungal agents; treatments are usually indicated empirically on the basis of clinical data. The knowledge of in vitro antifungal susceptibility is important to determine correct therapeutic guides for the treatment of fungal infections. Therefore, the objective of this study was to determine the antifungal susceptibility profile of oral Candida isolates from HIV-positive patients and control individuals. Amphotericin B, fluconazole, flucytosine, nystatin and ketoconazole were tested according to the methodology of microdilution proposed by the Clinical and Laboratory Standards Institute (CLSI); results were recorded in values of minimal...

Effectiveness of 2% peracetic acid for the disinfection of gutta-percha cones

Brazilian Oral Research — Sun, 27 Feb 2011 17:49:55 +0100

The aim of this study was to evaluate the effectiveness of 2% peracetic acid for the disinfection of gutta-percha cones contaminated in vitro with Escherichia coli, Staphylococcus aureus, Streptococcus mutans, Candida albicans and Bacillus subtilus (in spore form). Two hundred and twenty-five gutta-percha cones were contaminated with standardized suspensions of each microorganism and incubated at 37°C for 24 h. The cones were divided into 10 experimental groups (n = 15), according to the microorganism tested and disinfection testing times. The disinfection procedure consisted of immersing each cone in a plastic tube containing the substance. The specimens remained in contact with the substance for 1 or 2.5 minutes. Afterwards, each cone was transferred to a 10% sodium thiosulphate solutio...

Prevalence of malocclusions in the 13-20-year-old categories of football athletes

Brazilian Oral Research — Sun, 27 Feb 2011 17:49:55 +0100

The objective of this study is to research the presence of dental malocclusions in athletes of the category between 13 and 20 years of age, from the São Paulo Football Club. 84 athletes participated in this study, dealing with the following topics: molar relation (Angle's classification); presence of overbite; underbite; overcrowding; abnormal spacing; open bite; and anterior, posterior, bilateral and unilateral crossbite; midline deviation and facial type (mesofacial, brachyfacial and dolichofacial). Only one table was made, showing percentages. In regard to Angle's molar relation, 89% are in Class I, 8% in Class II, 3% Class III, 9% of the athletes had overbite, 4% had underbite, 13% had overcrowding and 21% had abnormal spacing. In regard to the bite, 11% presented anterior open bite. ...

Pulp capping materials exert an effect on the secretion of IL-1β and IL-8 by migrating human neutrophils

Brazilian Oral Research — Sun, 27 Feb 2011 17:49:55 +0100

The objective of this study was to analyze the effect of different pulp-capping materials on the secretion of interleukin-1 beta (IL-1β) and interleukin-8 (IL-8) by migrating human neutrophils. Neutrophils were obtained from the blood of three healthy donors. The experimental groups were calcium hydroxide [Ca(OH)2], an adhesive system (Single Bond), and mineral trioxide aggregate (MTA). Untreated cells were used as control. Transwell chambers were used in performing the assays to mimic an in vivo situation of neutrophil chemotaxis. The pulp-capping materials were placed in the lower chamber and the human neutrophils, in the upper chamber. The cells were counted and the culture medium was assayed using ELISA kits for detecting and quantifying IL-1β and IL8. The data were compared by ANOVA...

Low shrinkage composite resins: influence on sealing ability in unfavorable C-factor cavities

Brazilian Oral Research — Sun, 27 Feb 2011 17:49:55 +0100

The present investigation observed the sealing ability of low shrinkage composite resins in large and deep cavities, placed and photocured in one increment. Large, deep cavities (5.0 mm diameter and 2.5 mm deep) surrounded by enamel were prepared in bovine teeth, which were then divided into five groups. Groups 1, 2, 3 and 4: acid conditioning + Adper Single Bond (3M/ESPE, St Paul, MN, USA) and restoration with Aelite LS Posterior (BISCO Inc. Schaumburg, IL, USA) (G1); Filtek Z-350 (3M/ESPE,St Paul, MN, USA) (G2); Filtek Z-350 Flow (3M/ESPE, St Paul, MN, USA) (G3); Premisa (KERR Corporation, Orange, CA, USA) (G4). Group 5: Silorane Adhesive system (3M/ESPE, St Paul, MN, USA) + restoration with Filtek Low Shrinkage Posterior P90 (3M/ESPE, St Paul, MN, USA). After polymerization, the teeth w...

Revised publishing policy

Brazilian Oral Research — Sun, 27 Feb 2011 17:49:55 +0100

(Source: Brazilian Oral Research)

Promotion of Oral Health in the public and private context

Brazilian Oral Research — Sat, 18 Sep 2010 05:49:54 +0100

Patients frequently fail to achieve an optimal mechanical plaque control. However, many patients are not confident about using mouthrinses, and many professionals refuse to prescribe them for regular daily use. Aiming at achieving a better understanding of the use and prescription of mouthrinses in periodontics, 24 dentists with different dental educational levels were purposively chosen and interviewed in a qualitative research. Partial data was presented at the 15th Congress of the Brazilian Association for Oral Health Promotion (ABOPREV), and full data was presented at the 88th General Session and Exhibition of the International Association for Dental Research (IADR). The professionals' answers were confirmed or rejected through scientific data analysis. Additionally, scientifically sup...

Self-performed supragingival biofilm control: qualitative analysis, scientific basis and oral-health implications

Brazilian Oral Research — Sat, 18 Sep 2010 05:49:54 +0100

Oral cancer public policies: is there any evidence of impact?

Brazilian Oral Research — Sat, 18 Sep 2010 05:49:54 +0100

Investigation in oral cancer comprises many different fields such as epidemiology, risk factors, biological markers, diagnostic testing, screening, treatment and prognosis. Although many researchers have dealt with the oral cancer problem, it is unknown if any public policy is capable of reducing its incidence around the world under the scrutiny of the scientific method. This paper aims to briefly review and discuss the literature regarding oral cancer public policies and to screen the evidence of controlled implementations of oral health policies that have been able to diminish oral cancer incidence around the globe. (Source: Brazilian Oral Research)

Proposal for the teaching of the chemical control of supragingival biofilm

Brazilian Oral Research — Sat, 18 Sep 2010 05:49:54 +0100

The mechanical control of supragingival biofilm is accepted as one of the most important measures to treat and prevent dental caries and periodontal diseases. Nevertheless, maintaining dental surfaces biofilm-free is not an easy task. In this regard, chemical agents, mainly in the form of mouthwashes, have been studied to help overcome the difficulties involved in the mechanical control of biofilm. The aim of this paper was to discuss proposals for the teaching of supragingival chemical control (SCC) in order to improve dentists' knowledge regarding this clinical issue. Firstly, the literature regarding the efficacy of antiseptics is presented, clearly showing that chemical agents are clinically effective in the reduction of biofilm and gingival inflammation when used as adjuvant agents to...

Financing national policy on oral health in Brazil in the context of the Unified Health System

Brazilian Oral Research — Sat, 18 Sep 2010 05:49:54 +0100

This article discusses the model of oral health care implemented in the Unified Health System of Brazil in the last decade. This model was conceived as a sub-sector policy that, over the years, has sought to improve the quality of life of the Brazilian population. Through a chronological line, the study presents the National Policy on Oral Health as a counter-hegemonic patient care model for the dentistry practices existing in the country before this policy was implemented. The reorganization of the levels of oral health care, the creation of reference facilities for secondary and tertiary care, through Centers of Dental Specialties and Regional Dental Prosthesis Laboratories, and the differential funding and decentralized management of financial resources were able to expand the actions o...

Health promotion and dental caries

Brazilian Oral Research — Sat, 18 Sep 2010 05:49:54 +0100

The central idea of the Brazilian health system is to prevent the establishment of disease or detect it as early as possible. Prevention and treatment of dental caries are related to behavioral factors, including dietary and oral hygiene habits, which are related to many chronic diseases. Dental health promotion therefore should be fully integrated into broadly based health-promoting strategies and actions such as food and health policies, and general hygiene (including oral hygiene), among others. For decades, a linear relationship between sugar consumption and caries has been observed. Recent data has indicated that this relationship is not as strong as it used to be before the widespread use of fluoride. However, diet is still a key factor acting in the carious process. Oral hygiene is ...

Fluoride: its role in dentistry

Brazilian Oral Research — Sat, 18 Sep 2010 05:49:54 +0100

In spite of decades of research on fluoride and the recognition of its role as the cornerstone of dental caries reduction in the last fifty years, questions still arise on its use at community, self-applied and professional application levels. Which method of fluoride delivery should be used? How and when should it be used? How can its benefits be maximized and still reduce the risks associated with its use? These are only some of the challenging questions facing us daily. The aim of this paper is to present scientific background to understand the importance of each method of fluoride use considering the current caries epidemiological scenario, and to discuss how individual or combined methods can be used based on the best evidence available. (Source: Brazilian Oral Research)

Contributing to ultimately offering quality oral health care to all Brazilians

Brazilian Oral Research — Sat, 18 Sep 2010 05:49:54 +0100

(Source: Brazilian Oral Research)

Renewing a partnership to further research and improve oral health

Brazilian Oral Research — Sat, 18 Sep 2010 05:49:54 +0100

(Source: Brazilian Oral Research)

Use of the plasma CTX for assessing the bone activity of the mandible among osteopenic and osteoporotic patients