Resumo em Inglês:

The aim of this study was to assess the frequency of routine use of dental prophylaxis prior to visual inspection, in order to diagnose caries, by dentists with different lapses of time after graduating time. One hundred and fifty one Brazilian dentists were interviewed in 3 Brazilian cities to determine if they usually remove dental plaque prior to visual inspection for caries diagnosis. The dentists were stratified according to year of graduation. The association between the lapse of time after graduating and the practice of routinely removing dental plaque before clinical examination was tested using the chi-square test with a significance level of 5%. Only 28.5% of the dentists reported that they usually remove dental plaque prior to clinical examination. The dentists who graduated in the last 15 years presented the lowest percentages of plaque removal prior to clinical examination (15.1%), whereas the more experienced dentists reported that they perform prophylaxis more frequently. Of the professionals who graduated from 1960-1975, 23.9% reported that they performed dental plaque removal prior to diagnosis, whereas the figure for those graduating from 1976-1990 was 46.2%. Most of the dentists interviewed reported that they did not remove dental plaque prior to performing visual diagnosis of caries.

Resumo em Inglês:

This study evaluated the Knoop hardness of a dual-cured resin cement (Rely-X ARC) activated solely by chemical reaction (control group) or by chemical / physical mode, light-cured through a 1.5 mm thick ceramic (HeraCeram) or composite (Artglass) disc. Light curing was carried out using conventional halogen light (XL2500) for 40 s (QTH); light emitting diodes (Ultrablue Is) for 40 s (LED); and Xenon plasma arc (Apollo 95E) for 3 s (PAC). Bovine incisors had their buccal face flattened and hybridized. On this surface a rubber mold (5 mm in diameter and 1 mm in height) was bulk filled with the resin cement. A polyester strip was seated for direct light curing or through the discs of veneering materials. After dry storage in the dark (24 h 37°C), the samples (n = 5) were sectioned for hardness (KHN) measurements, taken in a microhardness tester (50 gF load 15 s). The data were statistically analyzed by ANOVA and Tukey's test (α = 0.05). The cement presented higher Knoop hardness values with Artglass for QTH and LED, compared to HeraCeram. The control group and the PAC/Artglass group showed lower hardness values compared to the groups light-cured with QTH and LED. PAC/HeraCeram resulted in the worst combination for cement hardness values.

Resumo em Inglês:

This study aimed to evaluate the diffusion capacity of calcium hydroxide pastes with different vehicles through dentinal tubules. The study was conducted on 60 extracted single-rooted human teeth whose crowns had been removed. The root canals were instrumented and divided into 4 groups according to the vehicle of the calcium hydroxide paste: Group I - distilled water; Group II - propylene glycol; Group III - 0.2% chlorhexidine; Group IV - 2% chlorhexidine. After placement of the root canal dressings, the teeth were sealed and placed in flasks containing deionized water. After 1, 2, 7, 15, 30, 45 and 60 days, the pH of the water was measured to determine the diffusion of calcium hydroxide through the dentinal tubules. The data were recorded and statistically compared by the Tukey test. The results showed that all pastes presented a similar diffusion capacity through dentin. Group IV did not present difference compared to group I. Group II presented difference compared to the other groups, as did Group III. In conclusion, groups I and IV presented a better diffusion capacity through dentin than groups II and III; 2% chlorhexidine can be used as a vehicle in calcium hydroxide pastes.

Resumo em Inglês:

The purpose of this study was to evaluate the radiopacity of root canal sealers containing calcium hydroxide and MTA (Acroseal, Sealer 26, Sealapex, Endo CPM Sealer, Epiphany and Intrafill). Five disc-shaped specimens (10 x 1 mm) were fabricated from each material, according to the ISO 6876/2001 standard. After setting of the materials, radiographs were taken using occlusal film and a graduated aluminum stepwedge varying from 2 to 16 mm in thickness. The dental X-ray unit (GE1000) was set at 50 kVp, 10 mA, 18 pulses/s and distance of 33.5 cm. The radiographs were digitized and the radiopacity compared to that of the aluminum stepwedge using VIXWIN-2000 software (Gendex). The data (mmAl) were analyzed statistically by ANOVA and Tukey's test at the 5% significance level. Epiphany and Intrafill presented the highest radiopacity values (8.3 mmAl and 7.5 mmAl respectively, p < 0.05) followed by Sealer 26 (6.3 mmAl), Sealapex (6.1 mmAl) and Endo CPM Sealer (6 mmAl). Acroseal was the least radiopaque material (4 mmAl, p < 0.05). In conclusion, the calcium hydroxide- and MTA-containing root canal sealers had different radiopacities. However, all materials presented radiopacity values above the minimum recommended by the ISO standard.

Resumo em Inglês:

A cross-sectional study was carried out to determine the prevalence, severity and impact of toothache among schoolchildren associated with socio-demographic variables (gender, degree of maternal schooling, economic group, and oral health status). Six hundred and one 8- and 9-year-old children were randomly selected from schools in Belo Horizonte, MG, Brazil. After formal authorization was obtained from their parents, the children were interviewed and clinically examined by a single examiner. The Chi squared test was applied and the odds ratio obtained. The prevalence of toothache was 45.9% (276/601), of which 15.6% (94/601) had occurred during the previous month. Among the children who had experienced pain, 39.4% (109/276) classified its severity as intense or very intense. Nearly 35% (96/276) were awoken by the pain, and 63.8% (176/276) were unable to carry out daily tasks as a result. The prevalence of pain was greater among children from less privileged economic groups, in which the mothers' level of schooling was lower (0-7 years of formal study) and who showed poorer conditions of oral health, determined by the presence of dental and periodontal pathology (p<0.05). Gender did not influence either the experience of toothache or its severity and impact. The prevalence of toothache found in the age group between 8 and 9 years is very high and associated to social determinants and poorer conditions of oral health.

Resumo em Inglês:

At present the major consideration in planning an implant design is to seek biocompatible surfaces that promote a favorable response from both cells and host tissues. Different treatments of implant surfaces may modulate the adhesion, proliferation and phenotypic expression of osteoblastic cells. For this reason, the aim of the present study was to evaluate the biocompatibility of an implant surface, observing adhesion, cell morphology and proliferation of osteoblast-like cells cultivated on a commercially available titanium dental implant (Titamax Liso®, Neodent, Curitiba, PR, Brazil). The implant samples were immersed into an osteoblast-like cell (Osteo-1) suspension for a period of 24, 48 and 72 hours. After seeding the cells, the samples were prepared for analyses through scanning electron microscopy. Based on the surface analysis, the osteoblastic cells adhered to the machined surface after 24 hours in culture. In 48 hours, the cells spread over the implant surface, and after 72 hours a proliferation of cells with large and flat bodies was observed over the machined implant surface. These results demonstrate that the machined titanium surface studied is biocompatible since it allowed adhesion and proliferation of the osteoblast-like cells, in addition to preserving cell integrity and the morphologic characteristics of cells during the studied period.

Resumo em Inglês:

The purpose of the present study was to evaluate, using a biomechanical test, the force needed to remove implants with surface modification by laser (Nd:YAG) in comparison with implants with machined surfaces. Twenty-four rabbits received one implant with each surface treatment in the tibia, machined surface (MS) and laser-modified surface (LMS). After 4, 8 and 12 weeks of healing, the removal torque was measured by a torque gauge. The surfaces studied were analyzed according to their topography, chemical composition and roughness. The average removal torque in each period was 23.28, 24.0 and 33.85 Ncm for MS, and 33.0, 39.87 and 54.57 Ncm for LMS, respectively. The difference between the surfaces in all periods of evaluation was statistically significant (p < 0.05). Surface characterization showed that a deep and regular topography was provided by the laser conditioning, with a great quantity of oxygen ions when compared to the MS. The surface micro-topography analysis showed a statistical difference (p < 0.01) between the roughness of the LMS (Ra = 1.38 ± 0.23 μm) when compared to that of the MS (Ra = 0.33 ± 0.06 μm). Based on these results, it was possible to conclude that the LMS implants' physical-chemical properties increased bone-implant interaction when compared to the MS implants.

Resumo em Inglês:

One of the greatest challenges faced by buccomaxillofacial prosthetists is to reproduce the patient's exact skin color and provide adequate esthetics. To reach this objective, professionals must use materials with easy characterization and that maintain color over long periods of time. The objective of this study was, thus, to evaluate the color stability of two types of silicones, Silastic 732 and Silastic MDX4-4210. Twenty-four test specimens were made from each type of silicone and were divided into a colorless group and groups intrinsically pigmented with ceramics, cosmetics or iron oxide. The specimens were submitted to an accelerated system of aging for non-metallic materials. Readings were carried out initially and after periods corresponding to 163, 351, 692 and 1,000 hours of aging, using a reflection spectrophotometer analysis, and color alterations were calculated by the CIE L*a*b* system. The data were submitted to variance analysis and Tukey's test at a 5% level of probability. The results demonstrated that, irrespective of the period of time analyzed, all the materials underwent some type of chromatic alteration (ΔE > 0). The test specimens made with Silastic 732 and MDX4-4210, without pigmentation, presented the lowest color alteration values after 1,000 hours of aging. Of the pigments, ceramic presented the lowest color alteration values and cosmetic powder presented the highest values. Thus, it may be concluded that the materials without the incorporation of pigments presented similar color alteration values, and did not differ statistically. The cosmetic powder used in this study was the pigment that most altered the color of the test specimens.

Resumo em Inglês:

The prevalence of HIV-related oral lesions may vary according to socioeconomic status and antiretroviral therapy, among other factors. This study's intent was to evaluate the association between socioeconomic indicators, CD4+ counts and HIV-related oral lesions in the city of Rio de Janeiro, RJ, Brazil. A retrospective epidemiological analysis was performed of the medical records of HIV-positive patients that attended the Federal University of Rio de Janeiro between 1997 and 2004. Gender, age, mode of HIV transmission, level of education, monthly familial income, CD4+ counts and HIV-related oral lesions were assessed. For statistical analysis, the Chi-square test was used with a level of significance of 5%. 254 medical records were reviewed: 83 women and 171 men. Monthly familial income below 2 minimum wages was associated with a higher prevalence of pseudomembranous candidiasis (p = 0.024), while income above 10 minimum wages was associated with a higher prevalence of salivary gland disease (p = 0.021). Lower socioeconomic status was associated with lower CD4+ counts (p = 0.017). In this study, an association was noted between socioeconomic status, immune suppression and prevalence of oral lesions. However, further studies are warranted using other socioeconomic variables in order to better assess this relationship.

Resumo em Inglês:

The purpose of the present study was to evaluate the relationship between psychological variables and the clinical diagnosis of temporomandbular disorders (TMD) in 12-year-old adolescents. TMD pain was assessed by RDC/TMD examination (Research Diagnostic Criteria for Temporomandibular Disorders) (Axis I and II). Five-hundred and fifty-eight subjects (330 girls and 228 boys) were examined. Bivariate analyses were performed using the Chi-square test (χ2). The logistic regression models were adjusted estimating the Odds Ratios (OR), their 95% confidence intervals (CI), and significance levels. Only 2.19% of the boys and 8.18% of the girls presented one of the Axis I categories. All variables from axis II were related to TMD diagnosis (p < 0.001). Gender was significantly related to TMD diagnosis (p = 0.0028). The risk of TMD incidence for girls was 3.5 times higher than that for boys (Odds Ratio = 3.52, Confidence Interval 1.31-9.43). The individuals who presented the variable "characteristics of pain intensity" (CPI) higher than 0 had 31 times more risk of TMD incidence (Odds Ratio = 31.361, Confidence interval 6.01-163.5). We concluded that psychological variables and female gender are important risk indicators related to TMD incidence, even in adolescents.

Resumo em Inglês:

The aim of this study was to evaluate the stress distribution in the cervical region of a sound upper central incisor in two clinical situations, standard and maximum masticatory forces, by means of a 3D model with the highest possible level of fidelity to the anatomic dimensions. Two models with 331,887 linear tetrahedral elements that represent a sound upper central incisor with periodontal ligament, cortical and trabecular bones were loaded at 45º in relation to the tooth's long axis. All structures were considered to be homogeneous and isotropic, with the exception of the enamel (anisotropic). A standard masticatory force (100 N) was simulated on one of the models, while on the other one a maximum masticatory force was simulated (235.9 N). The software used were: PATRAN for pre- and post-processing and Nastran for processing. In the cementoenamel junction area, tensile forces reached 14.7 MPa in the 100 N model, and 40.2 MPa in the 235.9 N model, exceeding the enamel's tensile strength (16.7 MPa). The fact that the stress concentration in the amelodentinal junction exceeded the enamel's tensile strength under simulated conditions of maximum masticatory force suggests the possibility of the occurrence of non-carious cervical lesions such as abfractions.

Resumo em Inglês:

Because a greater research effort has been directed to analyzing the adhesive effectiveness of self etch primers to dentin, the aim of this study was to evaluate, by microtensile testing, the bond strength to enamel of a composite resin combined with a conventional adhesive system or with a self-etching primer adhesive, used according to its original prescription or used with previous acid etching. Thirty bovine teeth were divided into 3 groups with 10 teeth each (n= 10). In one of the groups, a self-etching primer (Clearfil SE Bond - Kuraray) was applied in accordance with the manufacturer's instructions and, in the other, it was applied after previous acid etching. In the third group, a conventional adhesive system (Scotchbond Multipurpose Plus - 3M-ESPE) was applied in accordance with the manufacturer's instructions. The results obtained by analysis of variance revealed significant differences between the adhesive systems (F = 22.31). The self-etching primer (Clearfil SE Bond) presented lower enamel bond strength values than the conventional adhesive system (Scotchbond Multipurpose Plus) (m = 39.70 ± 7.07 MPa) both when used according to the original prescription (m = 27.81 ± 2.64 MPa) and with previous acid etching (m = 25.08 ± 4.92 MPa).

Resumo em Inglês:

A comparative and qualitative analysis of the tensions generated in the cantilever region of an implant-supported mandibular complete denture was conducted using the three-dimensional finite element method. The mechanical properties of the components were input in the model and a load of 15 N was applied in pre-determined points. In the first simulation, the load was applied on the occlusal surface of the first premolar. In the second simulation, it was applied on the first and second premolars. In the third simulation, it was applied on the first and second premolars and on the first molar. The different occlusion patterns produced similar tension distributions in the cantilever region, which followed a similar pattern in the three simulations. In all of the cases, the highest levels of tension were located in the region of the first implant. However, as the loads were dislocated distally, the tensions increased considerably. The more extensive the cantilever, the more compromised will be the infrastructure, the prosthetic components and the implants. Regardless of the length of the cantilever, the highest tensions will always be located in the region of the implant next to the load application point.

Resumo em Inglês:

The present study aimed to evaluate the need for orthodontic treatment in Brazilian schoolchildren presenting both late mixed dentition and early permanent dentition as well as to determine the possible factors associated with this necessity. Our randomly selected sample consisted of 407 schoolchildren aged between 9 and 12 years from Nova Friburgo (State of Rio de Janeiro), Brazil. All the children were evaluated according to the two components of the Index of Orthodontic Treatment Need (IOTN), namely, the Dental Health Component (DHC) and the Aesthetic Component (AC). Data analysis involved multiple logistic regression. Definite need for orthodontic treatment was found in 34.2% and 11.3% of the children according to, respectively, DHC and AC. The most prevalent malocclusions included the following: contact point displacement (crowding), crossbite, and increased overjet. Male gender, permanent dentition and aesthetic reasons were factors associated with a great need for orthodontic treatment. It was concluded that about one-third of the children evaluated had a definite need for orthodontic treatment. This necessity was greater in the permanent dentition, thus emphasizing the importance of an early identification of malocclusions and a timely referral of patients for treatment. The correlation between AC and DHC was considered important since they involve distinctive characteristics.

Resumo em Inglês:

The aim of this study was to comparatively assess dental arch width, in the canine and molar regions, by means of direct measurements from plaster models, photocopies and digitized images of the models. The sample consisted of 130 pairs of plaster models, photocopies and digitized images of the models of white patients (n = 65), both genders, with Class I and Class II Division 1 malocclusions, treated by standard Edgewise mechanics and extraction of the four first premolars. Maxillary and mandibular intercanine and intermolar widths were measured by a calibrated examiner, prior to and after orthodontic treatment, using the three modes of reproduction of the dental arches. Dispersion of the data relative to pre- and posttreatment intra-arch linear measurements (mm) was represented as box plots. The three measuring methods were compared by one-way ANOVA for repeated measurements (α = 0.05). Initial / final mean values varied as follows: 33.94 to 34.29 mm / 34.49 to 34.66 mm (maxillary intercanine width); 26.23 to 26.26 mm / 26.77 to 26.84 mm (mandibular intercanine width); 49.55 to 49.66 mm / 47.28 to 47.45 mm (maxillary intermolar width) and 43.28 to 43.41 mm / 40.29 to 40.46 mm (mandibular intermolar width). There were no statistically significant differences between mean dental arch widths estimated by the three studied methods, prior to and after orthodontic treatment. It may be concluded that photocopies and digitized images of the plaster models provided reliable reproductions of the dental arches for obtaining transversal intra-arch measurements.

Resumo em Inglês:

Oral cancers have a tendency to invade the surrounding bone structures, and this has a direct influence on the treatment management and on outcomes. The objective of this study was to correlate the clinical parameters (location, clinical presentation and TNM staging) of oral malignant tumors that can be associated with a potential of bone invasion and determine the accuracy of clinical examination to predict bone involvement, using computed tomography (CT). Twenty five patients, with oral malignant tumors were submitted to clinical and CT examinations. CT was considered the standard parameter to evaluate the presence of bone involvement. Clinical assessment of location, presentation form and TNM staging of the tumors were then compared to the CT findings in predicting bone involvement. Bone involvement was observed in 68% of the cases. It was predicted that tumors located in the retromolar trigone and hard palate, with a clinical aspect of infiltrative ulcer or nodule and classified in stage IV had a high potential to cause bone involvement. The clinical examination assessment of these tumors showed to be a valuable tool to predict bone invasion, with high sensitivity (82%) and specificity (87.5%), based on the results found in the CT images. No statistical significance was found between the CT and clinical examinations regarding bone involvement. The identification of some clinical parameters such as location, clinical presentation, and TNM stage, associated with a detailed clinical examination, was considered a valuable tool for the assessment of bone destruction by oral malignant tumors.

Resumo em Inglês:

The aim of this cross-sectional study was to examine the relationship between the composition of the subgingival microbiota and the vitamin D receptor (VDR) gene polymorphism in Brazilian adults with chronic periodontitis. The clinical parameters of probing depth, clinical attachment level, bleeding on probing, plaque accumulation and suppuration were measured in 60 Caucasian adults who were divided into two groups: 30 healthy individuals (control) and 30 with chronic periodontitis (ChP). Subgingival plaque samples were collected from 6 sites per subject and analyzed for 38 bacterial species using the Checkerboard DNA-DNA Hybridization. DNA was obtained from the subjects' epithelial cells by scraping the buccal mucosa and using a mouthwash containing 3% of glucose. Polymorphism in the VDR gene was analyzed by the polymerase chain reaction (PCR), followed by Taql digestion (RFLP). The healthy subjects presented significantly lower levels (0.3 × 10(7) ± 0.7 × 10(7)) of total microbial counts in comparison with subjects with chronic periodontitis (4.5 × 10(7) ± 2.9 × 10(7)). Regarding the occurrence of VDR polymorphism, it was observed that the Tt genotype was more prevalent in the Periodontitis group (60%) than in the Healthy group (30%), while the prevalences of the TT genotype were 23.3% and 53.3%, respectively (Chi-square test, p < 0.05). No difference was found in the composition of subgingival microbiota among the VDR genotypes evaluated for the Healthy and Periodontitis groups. In conclusion, the Tt genotype was associated with periodontal disease; however, no association with the subgingival microbiota was observed.

Resumo em Inglês:

This study aimed to assess the prevalence of aggressive periodontitis (AgP), and to investigate the association between demographic, socioeconomic and behavioral risk indicators with AgP in an untreated and isolated young population in Southeastern Brazil. For this cross-sectional survey, 134 subjects aged 12-29 years were selected by a census. Of those eligible, 101 subjects received a full-mouth clinical examination, and were interviewed using a structured written questionnaire. Cases were defined as individuals with 4 or more teeth with attachment loss > 4 mm or > 5 mm in the age groups 12-19 and 20-29, respectively. Overall, 9.9% of the subjects presented AgP (10.3% of the 12-19-year-olds and 9.7% of the 20-29-year-olds). The only risk indicator significantly associated with AgP in this isolated population was a high proportion of sites (> 30%) presenting supragingival calculus [OR = 23.2]. Having experienced an urgency dental treatment was a protective factor for AgP [OR = 0.1]. The authors concluded that this isolated and untreated population from Brazil presented a high prevalence of AgP. Local plaque-retaining factors played a major role in the prevalence of AgP in this isolated population, and should be included in further studies evaluating this destructive periodontal disease form.

Resumo em Inglês:

The aim of this study was to determine the prevalence of enamel white spots and the quality of oral hygiene in children up to 36 months old, in municipalities with different fluoride levels in the water supply, analyzing the contribution of several variables. After approval of the Ethics Committee, the parents signed an informed consent form and were interviewed about their educational level, economic classification of the family, nursing habits, use of toothpaste, access to dental service and other information. The children were clinically examined using the same codes and criteria established by the WHO (World Health Organization) and ADA (American Dental Association). The data were processed and analyzed with the Epi-info software program, version 3.2, and Microsoft Excel. Fisher's exact test (p<0.05) was applied to assess the association among the variables. The enamel white spot prevalence was 30.8% and the age group, duration of the bedtime milk feeding habit, age of initial practice of oral hygiene and presence of caries lesions with cavitation were considered statistically significant with regard to enamel white spot prevalence (p < 0.05). No association was found between oral hygiene quality and the study variables.