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Background: Bleaching gel thickeners induce important changes in tooth enamel and these changes are reversed by saliva., Objective: This in situ study aimed to evaluate the effect of bleaching gels with different thickeners on tooth enamel under normal and hyposalivation conditions., Methodology: Of 28 participants, 14 had normal salivary flow and 14 had low salivary flow. For each salivary flow, four types of treatment were performed with different thickeners: no bleaching (negative control), bleaching with a commercial 10% carbamide peroxide (CP) gel with carbopol (positive control) and bleaching with experimental 10% CP gels with natrosol and aristoflex. Participants used a palatal appliance containing bovine enamel/dentin specimens for 15 days. From day 2 to day 15, specimens were bleached extraorally. The bleaching gel was applied according to the groups for four hours. When the bleaching gel was removed, the palatal appliance was inserted again in the participants' mouth until the next day for another bleaching application. This procedure was repeated for 14 days and on day 15, surface microhardness (SMH), color (ΔE*ab and ΔE00), surface roughness (Ra), scanning electron microscopy (SEM), and energy-dispersive X-ray spectrometry (EDS) analyses were performed and data were subjected to statistical analysis., Results: Neither salivary flow nor thickeners influenced ΔE*ab and ΔE00 results. Carbopol had the lowest SMH, the highest Ra, and the lowest Ca% among all groups. For normal flow, natrosol and aristoflex had higher SMH. For low flow, aristoflex had higher SMH and natrosol and aristoflex had lower Ra. Aristoflex had higher Ca% and Ca/P and differed from carbopol for normal flow., Conclusion: For normal flow, 10% CP gels with natrosol and aristoflex caused fewer surface changes, and for low flow, only the 10% CP gel with aristoflex.

Objective: This study was designed to evaluate the potential adjunctive benefits of platelet-rich plasma (PRP) when used with guided-tissue regeneration (GTR) and bioactive glass (BG) in the treatment of Class II furcation lesions., Material and Methods: Bilateral Class II furcation lesions were surgically created and allowed to become chronic in the mandibular third premolars of 9 dogs. The defects were randomly assigned to: A) GTR+BG and B) GTR+BG+PRP. Similar defects were created in the maxillary third premolars and received the same treatments after 45 days. Dogs were sacrificed 90 days after the first treatment. The histometric parameters evaluated were: connective tissue adaptation, new cementum, new bone, mineralized bone area, non-mineralized bone area, and residual BG particle area., Results: Data analysis showed a superior length of new cementum and a greater mineralized bone area for group B in both periods (p<0.05). The non-mineralized bone area was greater in the control group (p<0.05) in both periods., Conclusion: Within the limits of this study, it can be concluded that the use of PRP in the treatment of Class II furcation defects may enhance the amount of new cementum and provide a more mineralized bone in a shorter period of time.

Objective: The aims of this study were to investigate the effectiveness of sealant placement under the guidelines of the Oral Health Promotion Program for Children and Adolescents (Portugal), and to test the influence of clinical and socioeconomic variables on the DMFT increment in 277 children, born in 1997., Material and Methods: A dental hygienist performed the initial examinations and sealant placement (Helioseal, Vivadent) on the permanent first molars in 2005. These activities were registered in dental records that were assessed in 2007. Children were classified according to caries risk at baseline [high (HR: DMFT+dmft>0); low (LR: DMFT+dmft=0) risk] and sealant placement as follows: HR-S and LR-S Groups (with sealant placement); HR-NS and LR-NS Groups (without sealant placement). A calibrated dentist performed the final examination in 2007 at school, based on the World Health Organization recommendations. The variables collected were: dental caries, visible dental plaque, malocclusions, and socioeconomic level (questionnaire sent to children's parents). For univariate (Chi-square or Fisher tests) and multivariate (Multiple logistic regression) analyses the DMFT increment >0 was selected as dependent variable., Results: Approximately 17.0% of the children showed DMFT increment>0 (mean=0.25). High-risk children presented a significant increase in the number of decayed and/or filled teeth. These children had 7.94 more chance of developing caries. Children who did not receive sealant were 1.8 more prone to have DMFT increment >0., Conclusion: It appears that sealant placement was effective in preventing dental caries development. Moreover, the variables "risk" and "sealant placement" were predictors for DMFT increment in the studied children.

Unlabelled: Statistical analysis interpretation is a critical field in scientific research. When there is more than one main variable being studied in a research, the effect of the interaction between those variables is fundamental on experiments discussion. However, some doubts can occur when the p-value of the interaction is greater than the significance level., Objective: To determine the most adequate interpretation for factorial experiments with p-values of the interaction nearly higher than the significance level., Materials and Methods: The p-values of the interactions found in two restorative dentistry experiments (0.053 and 0.068) were interpreted in two distinct ways: considering the interaction as not significant and as significant., Results: Different findings were observed between the two analyses, and studies results became more coherent when the significant interaction was used., Conclusion: The p-value of the interaction between main variables must be analyzed with caution because it can change the outcomes of research studies. Researchers are strongly advised to interpret carefully the results of their statistical analysis in order to discuss the findings of their experiments properly.

Objective: The aim of this 2-year cohort study (2003 to 2005) was to investigate how caries experience, at initial lesions (early or non-cavited lesions) and cavited stages, predicts caries increment in permanent teeth in 7-10- year-olds., Material and Methods: The random sample of 765 children attending public schools in the city of Piracicaba, SP, Brazil, was divided into two groups: 423 children aged 7-8 years and 342 children aged 9-10 years. All subjects were examined by a calibrated examiner, using dental mirror and ball-ended probes, after tooth brushing and air-drying in an outdoor setting, based on the World Health Organization criteria. Active caries with intact surfaces were also recorded as initial lesion (IL). Univariate analysis was used for statistical analysis (Odds Ratios and Chi-square)., Results: The association between the DMFT (decayed, missing and filled teeth) increment and the presence of IL was significant only for 9-10-year-old children. The children with DMFT>0 at baseline were more prone to have DMFT increment, with the highest risk for caries increment occurring in children aged 7-8 years., Conclusions: The predictors of caries increment were the presence (at baseline) of caries experience in permanent teeth for both age groups (7-8; 9-10-year-olds) and the presence of the IL (at baseline) for 9-10-year-olds.

Objective: This study aimed to evaluate the possibility of any correlation between disc displacement and parameters used for evaluation of skull positioning in relation to the cervical spine: craniocervical angle, suboccipital space between C0-C1, cervical curvature and position of the hyoid bone in individuals with and without symptoms of temporomandibular dysfunction., Material and Methods: The patients were evaluated following the guidelines set forth by RDC/TMD. Evaluation was performed by magnetic resonance imaging for establishment of disc positioning in the temporomandibular joints (TMJs) of 30 volunteer patients without temporomandibular dysfunction symptoms and 30 patients with symptoms. Evaluation of skull positioning in relation to the cervical spine was performed on lateral cephalograms achieved with the individual in natural head position. Data were submitted to statistical analysis by Fisher's exact test at 5% significance level. To measure the degree of reproducibility/agreements between surveys, the kappa (K) statistics was used., Results: Significant differences were observed between C0-C1 measurement for both symptomatic (p=0.04) and asymptomatic (p=0.02). No statistical differences were observed regarding craniocervical angle, C1-C2 and hyoid bone position in relation to the TMJs with and without disc displacement. Although statistically significant difference was found in the C0-C1 space, no association between these and internal temporomandibular joint disorder can be considered., Conclusions: Based on the results observed in this study, no direct relationship could be determined between the presence of disc displacement and the variables assessed.

The purpose of this study was to identify risk indicators of high caries level at baseline (HCLB) based on cross-sectional data and predictors of high caries increment (HCI) based on a 7-year-follow-up examination in 6-8-year-old schoolchildren. Two hundred and six schoolchildren were examined in 1997 and in 2004 by the same two calibrated dentists, in Piracicaba, Brazil. At baseline, dental caries, presence of sealants, fluorosis, and oral hygiene status were recorded. The children's parents completed a questionnaire concerning socioeconomic level, fluoride use, dental service utilization, dietary and oral hygiene habits. HCLB and HCI were defined considering the upper quartile of the total caries experience distribution (dmfs+DMFS) and caries increment distribution, respectively. Logistic regression models were adjusted estimating the Odds Ratio (OR), 95% confidence intervals and p-values. Having white spot lesions (OR=5.25) was found to be a risk indicator of HCLB. Schoolchildren with dental fluorosis (OR=0.17) or those who brushed the teeth more than two times a day (OR=0.37) presented less probability of HCLB. The predictors of HCI were: dmfs>0 (OR=2.68) and mothers' educational level up to 8 years of schooling (OR=2.87). Clinical and socioeconomic variables were found to be risk indicators and/or predictors of dental caries in schoolchildren.

Objectives: a) to evaluate the interexaminer reliability in caries detection considering different diagnostic thresholds and b) to indicate, by using Kappa statistics, the best way of measuring interexaminer agreement during the calibration process in dental caries surveys., Methods: Eleven dentists participated in the initial training, which was divided into theoretical discussions and practical activities, and calibration exercises, performed at baseline, 3 and 6 months after the initial training. For the examinations of 6-7-year-old schoolchildren, the World Health Organization (WHO) recommendations were followed and different diagnostic thresholds were used: WHO (decayed/missing/filled teeth - DMFT index) and WHO + IL (initial lesion) diagnostic thresholds. The interexaminer reliability was calculated by Kappa statistics, according to WHO and WHO+IL thresholds considering: a) the entire dentition; b) upper/lower jaws; c) sextants; d) each tooth individually., Results: Interexaminer reliability was high for both diagnostic thresholds; nevertheless, it decreased in all calibration sections when considering teeth individually., Conclusion: The interexaminer reliability was possible during the period of 6 months, under both caries diagnosis thresholds. However, great disagreement was observed for posterior teeth, especially using the WHO+IL criteria. Analysis considering dental elements individually was the best way of detecting interexaminer disagreement during the calibration sections.

Objective: The purpose of this study was to investigate whether skeletal maturation using cephalometric radiographs could be used in a Brazilian population., Material and Methods: The study population was selected from the files of the Oral Radiological Clinic of the Dental School of Piracicaba, Brazil and consisted of 128 girls and 110 boys (7.0 to 15.9 years old) who had cephalometric and hand-wrist radiographs taken on the same day. Cervical vertebral bone age was evaluated using the method described by Mito and colleagues in 2002. Bone age was assessed by the Tanner-Whitehouse (TW3) method and was used as a gold standard to determine the reliability of cervical vertebral bone age. An analysis of variance and Tukey's post-hoc test were used to compare cervical vertebral bone age, bone age and chronological age at 5% significance level., Results: The analysis of the Brazilian female children data showed that there was a statistically significant difference (p<0.05) between cervical vertebral bone age and chronological age and between bone age and chronological age. However no statistically significant difference (p>0.05) was found between cervical vertebral bone age and bone age. Differently, the analysis of the male children data revealed a statistically significant difference (p<0.05) between cervical vertebral bone age and bone age and between cervical vertebral bone age and chronological age (p<0.05)., Conclusions: The findings of the present study suggest that the method for objectively evaluating skeletal maturation on cephalometric radiographs by determination of vertebral bone age can be applied to Brazilian females only. The development of a new method to objectively evaluate cervical vertebral bone age in males is needed.

Objective: The aim of this study was to determine the differences between the skeletal ages estimated by TW2 and TW3 methods through their RUS and Carpal systems., Material and Methods: A sample of two hundred and forty hand and wrist radiographs of male and female Brazilian children aged 84-199 months was evaluated by five observers. The Dunnet test was performed for statistical analysis., Results: Results showed higher skeletal ages estimated by TW2RUS than TW3RUS and Carpal for both genders. For girls a statistically significant difference (p<0.05) was observed between TW2RUS and TW3RUS over the entire age range. For boys this difference was observed from 108 months onwards. In general RUS skeletal ages were higher than the chronological age and Carpal skeletal ages for both genders. The overestimation of chronological age was smaller for TW3RUS than for TW2RUS, and this last system showed a statistically significant difference regarding chronological age over the entire age range for girls, whereas for boys this difference was seen from 132 months onwards. For girls TW3 RUS and Carpal showed a significant difference regarding chronological age in the oldest age groups; in boys TW3RUS did not show a significant difference regarding chronological age. For Carpal, these results were more variable., Conclusion: It seems reasonable to recommend the use of the TW3 system for the studied Brazilian population.

The coefficient of variation is a dispersion measurement that does not depend on the unit scales, thus allowing the comparison of experimental results involving different variables. Its calculation is crucial for the adhesive experiments performed in laboratories because both precision and reliability can be verified. The aim of this study was to evaluate and to suggest a classification of the coefficient variation (CV) for in vitro experiments on shear and tensile strengths. The experiments were performed in laboratory by fifty international and national studies on adhesion materials. Statistical data allowing the estimation of the coefficient of variation was gathered from each scientific article since none of them had such a measurement previously calculated. Excel worksheet was used for organizing the data while the sample normality was tested by using Shapiro Wilk tests (alpha = 0.05) and the Statistical Analysis System software (SAS). A mean value of 6.11 (SD = 1.83) for the coefficient of variation was found by the data analysis and the data had a normal distribution (p>0.05). A range classification was proposed for the coefficient of variation from such data, that is, it should be considered low for a value lesser than 2.44; intermediate for a value between 2.44 and 7.94, high for a value between 7.94 and 9.78, and finally, very high for a value greater than 9.78. Such classification can be used as a guide for experiments on adhesion materials, thus making the planning easier as well as revealing precision and validity concerning the data.