Resumo em Inglês:

AIM: In order to determine the reliability between two of these methodologically different method, this study evaluated the systematic and random errors of the method proposed by Tanaka and Johnston, which is based on the sum of mandibular permanent incisors, and the Huckaba method, which uses radiographs. METHODS: In a random sample of 28 plaster models of mandibular dental arches belonging to individuals of both genders, aged six to eleven years old, a single investigator performed the measurement of required space, according to the two methods evaluated. After 15 days, the measurements were repeated, and each of them was performed twice in sequence to calculate the repeatability and reproducibility conditions, and the systematic and random errors for each method. RESULTS: The random error of the method proposed by Huckaba was larger in terms of reproducibility (1.53 mm) and repeatability (0.57 mm) compared with the analysis proposed by Tanaka and Johnston (0.20 mm and 0.12 mm, respectively). CONCLUSIONS: The method proposed by Huckaba was proved to be inadequate in relation to reproducibility, with respect to the random error, and should be used with caution to measure the required space in the mandibular arch.

Resumo em Inglês:

AIM: To evaluate the effect of different radiant exposures on the degree of conversion (DC), Knoop hardness number (KHN), plasticization (P), water sorption (WS), and solubility (S) of different monomer resin-based composites. METHODS: Circular specimens (5 x 2 mm) were manufactured from methacrylate and silorane composite resins, and light-cured at 19.8, 27.8, 39.6, and 55.6 J/cm2, using second-generation LED at 1,390 mW/cm2. After 24 h, DC was obtained using a FT-Raman spectrometer equipped with a Nd:YAG laser, KHN was measured with 50-g load for 15 s, and P was evaluated on the top and bottom surfaces by the percentage of hardness reduction after 24 h immersed in absolute alcohol. WS and S were determined according to ISO 4049. Data were subjected to statistical analysis (α=0.05). RESULTS: Methacrylate material presented higher DC, KHN, P, and WS than silorane (p<0.05). There was no difference in the S values (p>0.05). The increased radiant exposures improved only the KHN (p<0.05). In general, top surfaces showed higher DC and KHN than bottom, for both materials (p<0.05). The increase of the radiant exposure did not improve most physical properties of the composites and were monomer-base dependent. CONCLUSIONS: Chemical composition of the composite resins resulted in different physical properties behavior and could affect the clinical longevity of dental restorations, but overall these properties were not influenced by the different radiant exposures evaluated in the study.

Resumo em Inglês:

AIM: To evaluate caries prevalence and associated factors in Quilombola communities. METHODS: The study involved a cross-sectional study with Quilombola communities in Southeastern Brazil, in 2011. The data were collected by interviews and clinical examination. The sample was checked for caries prevalence (dmft and DMFT index) by one trained and calibrated dentist, reaching acceptable levels of agreement for data collection. The data were analyzed using descriptive statistics and frequency distribution. The significance of the associations between the dependent variable (dental caries) and the independent variables was verified using chi-squared or Fisher's Exact tests. Variables with a p-value <0.25 were tested using multiple logistic regression models in order to keep those with a pd"0.05 value. Odds ratios were estimated using regression models and 95% confidence intervals. The population consisted of 171 quilombolas (97% of total). RESULTS: Mean dmft value was 1.91 (± 2.71) at age d"5 years and mean DMFT values were 1.20 (± 1.49), 3.50 (± 2.23), 10.3 (± 4.79), 22.9 (± 5.37), 22.8 (± 4.12), respectively in the age groups: 6-12, 13-18, 19-34, 35-59 years and 60 years or older. Age less than 5 years (p-value 0.014), own perception of oral health (p-value 0.040) and education level were variables associated with dental caries in permanent teeth and need for treatment in the deciduous dentition. CONCLUSIONS: High prevalence of dental caries indicates the need for restructuring the dental care provided to the quilombolas.

Resumo em Inglês:

AIM: To evaluate the immediate microtensile bond strength (µTBS) of three two-step etch-and-rinse adhesive systems applied under different dentin surface moisture conditions. METHODS: Class V cavities were prepared in seventy-two bovine incisors. Each tooth was randomly allocated into three groups, according to the adhesive system used: Single Bond 2 (SB), Prime & Bond 2.1 (PB) and XP Bond (XPB). Each group was divided in three subgroups, according to the dentin moisture condition: over-wet, moist and dry (n=8). For the moist subgroups the adhesive was applied as to the manufacturer's instructions; for the over-wet ones, without drying the cavity after the rinsing procedure; and for the dry subgroups, drying the surface for 20 s. The teeth were restored with Filtek Z-250 and stored in distilled water (24 h); next, each restoration was sectioned in beam-shaped specimens which were stored for 24 h at 37 °C. Each specimen was submitted to µTBS test (EMIC), and data were analyzed using two-way ANOVA and Tukey test (p<0.05). RESULTS: There was a statistically significant interaction between the adhesive system type and the dentin surface moisture condition (p=0.003). SB and XPB presented higher bond strength in the moist dentin condition, and PB showed high µTBS values in the dry substrate. CONCLUSIONS: The moisture condition influenced the bond strength between the adhesives and dentin. SB performed better in the moist condition, whereas PB and XPB showed satisfactory bond strength in the moist and in the dry substrates. The over-wet dentin condition only impaired bond strength to SB and XPB.

Resumo em Inglês:

AIM: This study evaluated saliva effects on enamel morphology surface after microabrasion technique. METHODS: Enamel blocks (16 mm2) obtained from bovine incisors were divided into 9 groups as follows: one control group (no treatment), four groups with microabrasion treatment using 35% phosphoric acid and pumice (H3PO4+Pum) and other four groups treated with 6.6% hydrochloric acid and silica (HCl+Sil). One group of each treatment was submitted to 4 frames of saliva exposure: without exposure, 1-h exposure, 24-h exposure, and 7-days exposure on in situ regimen. Nineteen volunteers (n=19), considered as statistical blocks, used an intraoral appliance containing the specimens, for 7 days. Enamel roughness (Ra) was tested before and after treatment, and after saliva exposure. Confocal laser scanning microscopy (CLSM) was used to evaluate qualitatively the enamel morphology. RESULTS: All groups exhibited increased Ra after microabrasion. With regards to saliva exposure, the treatment with HCl+Sil presented more susceptibility to the saliva action, but no period of time was efficient in re-establishing this characteristic compared with the control group. CLSM analysis showed reduction of the micro-abrasive damages during the experimental times. CONCLUSIONS: Seven days of saliva exposure were not sufficient for the treated enamel to reach its normal characteristics compared with the control group.

Resumo em Inglês:

AIM: To compare temporomandibular (TMD) subgroups classified according to the presence of localized pain (LP) or widespread pain (WP) in order to assess the quality of life domains and verify which components affect most the functional capacity of facial pain patients. METHODS: A cross-sectional study was conducted and the Short Form-36 Health Survey was applied in order to assess quality of life. Thirty-nine TMD/WP patients, 37 TMD/LP patients and 40 subjects free of TMD complaints were evaluated. RESULTS: TMD/WP patients differed significantly from healthy controls in all SF-36 components and TMD/LP patients ranked between them. It was also observed that patients with bodily pain and TMD with WP are respectively, 4.16 and 49.42 times more likely to have low functional capacity. CONCLUSIONS: Functional capacity in TMD subgroups was only affected by the presence of bodily pain and WP. These patients feature high chance of low functional capacity. Furthermore, TMD patients with localized and widespread pain share role-emotional impairments.

Resumo em Inglês:

AIM: To evaluate the bonding durability of materials used as sealants on different dentitions. METHODS: Deciduous (D) and permanent (P) molars were divided into four groups (n=5) and sealed with Fluroshield (F) and OptiBond FL (FL). Blocks of composite resin were built, stored in distilled water (24 h/37 °C), sectioned into 0.8 mm2 and tested at tensile (0.5 mm/min) after 24 h and 6 months. The fractures were observed and classified into adhesive, cohesive or mixed types. The data were analyzed using repeated measures ANOVA and Tukey test (α=5%), with tooth as the experimental unit. RESULTS: There were differences for dentition (p=0.0097), dental sealant (p=0.0019) and time (p=0.0001). At 24h the highest bond strength was observed for OptiBond FL on deciduous and permanent teeth, similar to Fluroshield at both dentitions. After 6 months the bond strength of OptiBond FL did not decrease in the permanent teeth, but decreased similar to Fluroshield in deciduous teeth, the bond strength of Fluroshield decreased similarly in both dentitions. CONCLUSIONS: The bond strength of dental sealants varied with the experimental conditions.

Resumo em Inglês:

AIM: The aim of this study was to evaluate the influence of acrylic resin immersion in different mouthwashes on hardness, roughness and color. METHODS: Specimens of an orthodontic self-cured acrylic resin (Orto Clas(r)) were produced and immersed in five mouthwashes: Plax(r) Classic (Colgate(r)); Plax(r) alcohol-free (Colgate(r)); Listerine(r) (Johnson & Johnson(r)); Periogard(r) (Colgate(r)) and Periogard(r) alcohol-free (Colgate(r)). Nine different immersion times were studied: 1, 2, 4, 6, 8, 10, 12, 24 h and 7 days, totalizing 45 groups. The specimens were evaluated before and after immersion by Knoop microhardness (n=5), roughness in Ra parameter (n=5), and colorimetric analysis, CIElab (n=3). RESULTS: All mouthwashes softened the acrylic resins after 7 days of immersion. PlaxÒ alcohol-free showed no statistically significant difference of softening between the immersion times. Listerine(r) showed softening after immersion at all times. Plax(r) alcohol-free and Listerine(r) showed significantly increased values of roughness after 12 h of immersion (p<0.05). Listerine(r) presented a significant increase in color variation after 12 h of immersion. CONCLUSIONS: Immersion in mouthwashes could influence acrylic resin hardness, roughness and color.

Resumo em Inglês:

AIM: To determine the association between dental caries, Body Mass Index (BMI) and sugar intake in children attending primary school. METHODS: A cross-sectional study was conducted with 91 children, with mean age of 3.9 years (sd = ±1.0), considering anthropometric measurements, according to standardized methodology of the Ministry of Health and occurrence of dental caries was recorded from clinical examinations (dmft). The sugar intake level was measured with a questionnaire that was applied to parents/caretakers of the children. The association of the variables was checked using a correlation with the Contingency C coefficient test. RESULTS: 33 (36.3%) children were at risk for overweight, overweight or obese. Of these, 10 (30.3%) had dmft >1. An association was found between sugar added to the bottle and child dmft (coeff. C = 0.5853 and p <0.0001) and also with BMI (coeff. C = 0.5693 and p <0.0001). There was no association between BMI and caries (chi-square = 0.1447 and p-value = 0.7036). CONCLUSIONS: It was concluded that there was a correlation between sugar intake and dmft and BMI, but not between caries and BMI.

Resumo em Inglês:

AIM: To evaluate the impact of different light-curing times on dentin microtensile bond strength of two restorative systems after 24 h and 6 months of water storage. METHODS: Standardized Class II preparations were performed in 56 freshly-extracted human molars (n = 7), restored with methacrylate- or silorane-based restorative systems, and light-cured using a light-emitting diode at 1390 mW/cm2 by the recommended manufacturers' time or double this time. After storage for 24 h at 37 oC, the teeth were sectioned to yield a series of 0.8-mm thick slices. Each slab was trimmed into an hourglass shape of approximately 0.64 mm2 area at the gingival dentin-resin interface. Specimens were tested using universal testing machine at crosshead speed of 0.5 mm/min until failure, after 24 h and 6 months of storage. Data were statistically analyzed by three-way ANOVA and Tukey's test (α = 0.05). RESULTS: The highest bond strength values were recorded for the groups restored with methacrylate system (p<0.001) as well as for extended light-curing time (p = 0.0034). There was no statistically significant difference between 24 h and 6 months storage on bond strength (p>0.05). CONCLUSIONS: Bond strength was influenced by the material and light-curing time, but the 6-month storage did not affect the bond strength of restorations.

Resumo em Inglês:

AIM: To investigate the associations between nutritive and non-nutritive sucking habits and the prevalence of anterior open bite, in children from Aragua-Venezuela and São Paulo-Brazil. METHODS: Seven calibrated examiners (κ = 0.89-1.0) performed clinical assessments in Venezuelans (N = 809) and Brazilians (N = 1,377) aged 3-6 years. Sucking habits were investigated using questionnaires answered by the mothers. Data were analyzed using logistic regression models (α = 0.05). RESULTS: Among 380 children with anterior open bite, 309 were Brazilians. Approximately 65% of Brazilians with pacifier-sucking habit lasting beyond 3 years of age had this malocclusion. Brazilians who prolonged pacifier and digit-sucking habits beyond 3 years of age have, respectively, 68.5 and 14.5 times more chances of presenting anterior open bite than children without sucking habits (p < 0.001). In Venezuelans with open bite, 37.7% had digit-sucking habits beyond 3 years of age, resulting in a high odds ratio (9.3; p < 0.001) when compared to children without this habit. No significant effect was found for bottle feeding. However, non-breastfed Venezuelan children or those breastfed for periods shorter than 6 months have a two-fold higher chance of presenting anterior open bite than children who were breastfed for longer periods, p = 0.008. CONCLUSIONS: Infant feeding had some effect on Venezuelan children, since insufficient breastfeeding was related to a higher prevalence of anterior open bite. Pacifier-sucking was more prevalent in Brazilians, corresponding to pronounced chances (8-68 times greater) of diagnosing anterior open bite in pacifier users compared to non-users. Among Venezuelans, on the other hand, digit-sucking effect surpassed that of pacifier use and was associated with far higher chances (6-9 times) for this malocclusion.

Resumo em Inglês:

AIM: To evaluate the influence of varying the water/powder ratio on the compressive strength of type IV mineral and synthetic casts. METHODS: Four commercial brands of type IV mineral and synthetic casts were evaluated: Durone, Herostone, Fuji Rock, and Elite Rock. Ninety-six test samples were prepared from a silicone matrix, according to ADA's standard no. 25. The samples were prepared according to the manufacturer's recommendations with a normal water/powder ratio (n = 12) and with 20% extra water (n = 12), forming the control (A) and experimental (B) subgroups, respectively. Compressive strength tests were performed using a universal testing machine EMIC (DL 2000) with a load cell of 2,000 kgf/cm2. The obtained data were analyzed statistically using two-way ANOVA and Tukey's test (α=5%). RESULTS: The synthetic Elite Rock cast was statistically different from the one obtained when the portion of water indicated by the manufacturer was used; no significant differences were found in the remaining casts when the proportion of water was increased by 20%. CONCLUSIONS: the groups of synthetic and mineral casts differed and the water increase (20%) did not cause significant difference on the compressive strength of the materials.

Resumo em Inglês:

AIM: To evaluate histometrically the effect of low and high caloric value of ethanol on ligature-induced bone loss in female rats. METHODS: Sixty female rats were divided into five groups of 12 animals each: Normal Control (water), Test A (low ethanol), Control A (low iso), Test B (high ethanol) and Control B (high iso). Control Groups A and B received diets with the same amount of calories consumed by Test Groups A and B, respectively, with ethanol replaced by isocaloric amounts of carbohydrate. Four weeks prior to the end of the experimental period, half of the rats in each group were randomly assigned to receive a ligature on mandibular molar, whereas the other half of group was left unligated. At 8 weeks, the animals were sacrificed, and the specimens were processed to obtain decalcified sections. The area of periodontal ligament and/or bone loss in the furcation region of the first molars was histometrically measured in five sections per specimen (mm²). RESULTS: Ethanol intake did not have effect on the alveolar bone loss in unligated teeth (p>0.05). However, in ligature-induced periodontitis, high value of calories associated with ethanol feeding enhanced the area of bone loss (p<0.05). CONCLUSIONS: The results of this study demonstrated that a low-ethanol diet did not affect the periodontium, while a high-ethanol diet may aggravate the progression of periodontitis, as demonstrated by the increased furcation region bone destruction in periodontal disease.

Resumo em Inglês:

AIM: To characterize the genetic variability of Streptococcus mutans isolates and to correlate this variability with different colonization profiles observed during dental caries in a sample of children. METHODS: S. mutans samples were isolated from the saliva of 30 children with varying histories of dental caries, and they were characterized according to morphological and biochemical markers and the sequences of their 16S-23S intergenic spacer region. The genetic variability of the isolates was first assessed using Random Amplified Polymorphic DNA (RAPD) markers. Next, the isolates were differentiated by sequencing a specific region of the gene encoding the enzyme glucosyltransferase B (gtfB). RESULTS: Characterization using RAPD markers uncovered significant genetic variability among the samples and indicated the existence of clusters, which allowed us to reconstruct both the origin and clinical history of the disease. By sequencing the 16S-23S intergenic region, it was found that all of the isolates belonged to the species S. mutans. Based on the genetic similarity of the isolates and pattern of amino acid variations identified by partial sequencing of the gtfB gene, base-pair changes were identified and correlated with different virulence patterns among the isolates. CONCLUSIONS: The partial sequencing of the gtfB gene can be a useful tool for elucidating the colonization patterns of S. mutans. As amino acid variations are likely to be correlated with differences in biological risk, molecular characterization, such as that described in this paper, could be the key for assessing the development of dental caries in children.

Resumo em Inglês:

AIM: To evaluate antimicrobial ability of neem leaf extract, 3% sodium hypochlorite (NaOCl) and 2% chlorhexidine (CHX) against Candida albicans. METHODS: Neem leaf extract was prepared by using absolute ethanol with fresh neem leaves, filtering the extract through muslin cloth, coarse residue and filter paper. Cultures of C. albicans were maintained on Brain Heart Infusion broth and Agar. The antimicrobial efficacy was checked using the Agar Diffusion and the zones of inhibition were measured. The results were statistically analysed using ANOVA test. Inter-group comparison was checked using Kruskal Wallis ANOVA and Mann Whitney tests (a=0.05). RESULTS: There was statistically significant difference between the zones of inhibition seen with 3% NaOCl and Neem extract with 2% CHX (p<0.05). There was no significant difference observed between Neem extract and 3% NaOCl. CONCLUSIONS: Efficacy of Neem extract is comparable to 3% NaOCl against C. albicans and it is significantly better than 2% CHX.