Impact of infected and noninfected human dentine debris on bone healing in rats.

AIM: To evaluate in vivo the bone tissue response of rats to varying amounts of infected and noninfected dentine debris. METHODOLOGY: Bone tissue reactions were evaluated histologically in 42 Wistar rats after 7, 30 and 60 days. For each animal, three surgical cavities were prepared on the femur and filled with varying amounts (5, 10 or 20 mg) of infected or noninfected dentine debris pellets. In the negative control group, the surgical cavities were not filled. At the end of each experimental period, the animals were euthanized. The samples were processed histologically and analysed using a light microscope. The presence and the severity of inflammatory reaction, as well as hard tissue deposition were evaluated. Data were subjected to statistical analysis and the effects of the dependent variables calculated using nonparametric tests Kruskal-Wallis and Mann-Whitney U with due Bonferroni corrections at P = 0.05. RESULTS: At 7 days, the presence of infected debris significantly increased the histopathological scores for neutrophils (P < 0.05), and abscess formation (P < 0.05). Noninfected debris scored significantly higher for lymphocyte infiltrate compared with the control group and infected debris (P < 0.05). Both infected and noninfected debris equally triggered eosinophil cells compared with no-dentine (P < 0.05). As for giant cells and macrophages, no difference was detected amongst the dentine groups (P > 0.05). Hard tissue deposition was similar regardless of the presence or the bacteriological status of the dentine (P = 1.00). None of the above histopathological parameters was significantly influenced by the amount of debris (P > 0.05). For all parameters evaluated, at 7 days of analysis, the inflammatory response was significantly more intense compared with 30 and 60 days (P < 0.05). Inflammatory parameters were scored similarly for the evaluated groups after 30 and 60 days (P > 0.05). However, hard tissue deposition has significantly increased after 30 days (P < 0.05). No difference was seen between 30 and 60 days of analysis (P = 1.00) for all histological parameters evaluated. CONCLUSION: The assumption that the amount of extruded debris may negatively affect the inflammatory response of bone tissue was not validated in the present in vivo animal study. Infected dentine may trigger acute inflammatory parameters especially during the first 7 days of contact with the tissue; however, in the long term, these negative effects are mitigated.

A scoping review of root canal revascularization: relevant aspects for clinical success and tissue formation.

The aim of this scoping study was to evaluate the survival rate and nature of tissue formed inside root canals of human immature permanent teeth with necrotic pulps (NIPT) under root canal revascularization (RCR). The search was performed in SciVerse Scopus®, PubMed/MEDLINE, Web of Science®, BIREME and in the grey literature up to November 2015. The keywords were selected using MeSH terms and DECs. Two independent reviewers scrutinized the records obtained considering specific inclusion criteria. The included studies were evaluated in accordance with a modified Arksey and O' Malley's framework. From 375 studies that were evaluated, 75 were included. A total of 367 NIPT were submitted to RCR, from which only 21 needed further endodontic treatment. The weighted mean follow-up time was 17.6 months. The data were derived mainly from case reports (69%) or small case series (15%). NaOCl [0.5-6%] was applied as the disinfecting solution in almost all studies. Triple antibiotic paste was as effective as Ca(OH)2 as on intracanal medicament. De novo tissue was cementum and poorly mineralized bone positive to bone sialoprotein (BSP) but negative to dentine sialoprotein (DSP). Failures were associated mainly with reinfection of the root canal. The majority of included studies reported a significant increase in both root length and width. However, as most of these data came from case reports, they must be interpreted with care, as most were focused on treatment successes (not failures). Therefore, well-designed randomized controlled trials comparing RCR with available apexification treatments are needed to address this gap in the literature.

Stem cell-based pulp tissue engineering: variables enrolled in translation from the bench to the bedside, a systematic review of literature.

Stem cell-based therapy (SC-BT) is emerging as an alternative for endodontic therapies. The interaction between stem cells and scaffolds plays a crucial role in the generation of a 'friendly cell' microenvironment. The aim of this systematic review was to explore techniques applied to regenerate the pulp-dentine complex tissue using SC-BT. An electronic search into the SciVerse Scopus (SS), ISI Web Science (IWS) and Entrez PubMed (EP) using specific keywords was performed. Specific inclusion and exclusion criteria were predetermined. The search yielded papers, out of which full-text papers were included in the final analyses. Data extraction pooled the results in four main topics: (a) influence of the chemical properties of the scaffolds over cell behaviour; (b) influence of the physical characteristics of scaffolds over cell behaviour; (c) strategies applied to improve the stem cell/scaffold interface; and (d) influence of cue microenvironment on stem cell differentiation towards odontoblast-like cells and pulp-like tissue formation. The relationship between the scaffolds, the environment and the growth factors released from dentine are critical for de novo pulp tissue regeneration. The preconditioning of dentine walls with ethylenediaminetetraacetic acid (EDTA) was imperative for successful pulp-dentine complex regeneration. An analyses of the grouped results revealed that pulp regeneration was an attainable goal.

Dental caries is associated with dental fear in childhood: findings from a birth cohort study.

OBJECTIVE: This study aimed to investigate the prevalence of dental fear in preschool children and to estimate its association with maternal and children characteristics. METHODS: The study was nested in a population-based birth cohort from Pelotas, Brazil, started in 2004. A sample of 1,129 children aged 5 years was dentally examined, and their mothers were interviewed. Dental fear was investigated using a validated instrument through the question 'Do you think that your child is afraid of going to the dentist?'. The possible answers were (1) 'no', (2) 'yes, a little', (3) 'yes' and (4) 'yes, a lot'. The outcome was dichotomized as 'children without dental fear' (answers 1 and 2) and 'children with dental fear' (answers 3 and 4). Exploratory variables included demographic characteristics, socioeconomic status, maternal oral health status and maternal behaviors. The main explanatory variables were caries and dental pain. Data were analyzed using multivariable Poisson regression. RESULTS: The prevalence of dental fear was 16.8% (95% confidence interval 14.6-19.0). Multivariate analysis showed that the lower the family income at birth and the higher the severity of dental caries, the higher the prevalence of dental fear. Children who never visited the dentist and those who frequently experienced dental pain were positively associated with higher dental fear prevalence. CONCLUSIONS: Presence of dental caries and dental pain were associated with dental fear regardless of socioeconomic origin and lack of dental service use in childhood.

A double-blind randomised clinical trial of two techniques for gingival displacement.

Knowledge about security and the potential damage originated by the gingival displacement techniques has not been described through randomised clinical studies. This crossover, double-blind, randomised clinical trial evaluated clinical and immunological factors related to conventional and cordless gingival displacement (GD) techniques, and patients' perceptions in 12 subjects with the employment of 2 GD techniques: conventional (gingival cord + 25% AlCl3 astringent gel) and cordless (15% AlCl3 astringent-based paste). In each subject, two anterior teeth were treated and a 10-day wash-out period separated the two treatments. Periodontal indices were evaluated before (baseline) and 1 and 10 days after GD. Interleukin 1ß, interleukin 6 and tumour necrosis factor α concentrations in gingival crevicular fluid were measured before and 1 day after GD. Subjective parameters (pain, unpleasant taste and stress) were also evaluated. Data were analysed by one-way repeated-measures analysis of variance and Tukey's test (immunological factors), the Friedman test (periodontal parameters) and Fisher's exact or chi-squared test (subjective parameters), with a significance level of 95%. Gingival bleeding index, probing depth and plaque index values did not differ significantly between groups at any timepoint. Neither technique resulted in worse periodontal indices. Both techniques yielded similar results for pain and unpleasant taste, but conventional GD was significantly more stressful than cordless GD for volunteers. Both treatments significantly increased mean concentrations of the three cytokines, with the conventional technique producing the highest cytokine levels. Cordless GD is less stressful for patients and results in lower post-treatment levels of inflammatory cytokines compared with conventional GD.

The Alcohol Harm Paradox in Periodontitis.

Individuals of lower socioeconomic position (SEP) experience a greater rate of alcohol-related harms, yet they consume equal or lower amounts of alcohol than higher-SEP individuals. This phenomenon, called the "alcohol harm paradox" (AHP), gained attention recently, and different mechanisms have been proposed to explain it. Since both SEP and alcohol have been suggested to be associated with periodontitis risk, we conducted a secondary analysis using data from the National Health and Nutrition Examination Survey 2011 to 2012 and 2013 to 2014 cycles, aiming to examine 1) whether the association between alcohol consumption and periodontitis is modified by SEP and 2) the extent to which the effect of SEP inequalities on periodontitis is mediated by and/or interacts with alcohol consumption. We set educational attainment as the main SEP proxy and tested the poverty income ratio in subsequent sensitivity analyses. Effect measure modification analysis was employed, considering heavy drinking as exposure, and causal mediation analysis based on the potential outcome's framework decomposed the effect of SEP on periodontitis in proportions attributable to mediation and interaction. Models were fitted using binary logistic regression and adjusted for sex, ethnicity, age, body mass index, smoking status, diabetes, binge drinking, and regular preventive dental visits. The analytical sample comprised 4,057 participants. After adjusting for covariates, less educated heavy drinkers presented 175% (odds ratio, 2.75; 95% confidence interval [CI], 2.04-3.72) higher odds of periodontitis than their counterparts, and super-additive associations were found (relative excess risk due to interaction: 1.35; 95% CI, 0.49-2.20). Additionally, -69.5% (95% CI, -122.1% to -16.8%) of the effects of education on periodontitis were attributable to interaction with heavy drinking, consistent with the AHP. No contribution was found for the mechanism of mediation. Heavy drinking disproportionately impacts the occurrence of periodontitis in lower-SEP individuals. Lower-SEP individuals seem to experience differential effects of heavy drinking on periodontitis.

Effect of weight satisfaction on adolescent facial and dental satisfaction.

PURPOSE: To investigate if facial and dental satisfaction is related to body fat percentage and body weight satisfaction. METHODS: A self-administered questionnaire was applied to adolescents from a Private School in Southern Brazil containing sociodemographic (sex and age) and self-perception variables. Adolescents were asked about their perceptions concerning dental problems. Body fat percentage was collected using bioelectrical impedance analysis. RESULTS: A total of 372 adolescents were examined. Most adolescents were satisfied with their dental (81.7%) and facial appearance (87.6%), while 39% of adolescents were satisfied with their body weight. Poisson regression model showed that adolescents who expressed satisfaction with their body weight (PR = 1.12, 95%CI 1.06-1.19) and were satisfied with their dental appearance (PR = 1.24, 95% CI 1.08-1.41) exhibited a positive association with facial satisfaction. Adolescents dissatisfied with dental color (PR = 0.88, 95%CI 0.80-0.97), those reporting dental pain (PR = 0.88, 95%CI 0.80-0.97), and individuals with obesity (PR = 0.91, 95%CI 0.83-0.99) demonstrated a decrease in facial satisfaction. Adolescents aged 16 to 19 years (PR = 1.08, 95% CI 1.01-1.15) and those satisfied with their facial appearance (PR = 1.20, 95%CI 1.01-1.43) exhibited a higher prevalence of dental satisfaction. Conversely, adolescents dissatisfied with dental color (PR = 0.74, 95% CI 0.66-0.82) and those with misaligned teeth (PR = 0.63, 95%CI 0.55-0.73) reported lower levels of dental satisfaction. Parametric g-formula analysis found that the association between body fat and facial satisfaction was mediated by body weight satisfaction (p = 0.001). CONCLUSIONS: While dental satisfaction was not influenced by corporeal characteristics, facial satisfaction was influenced by dental and body weight satisfaction. Obese adolescents had low facial satisfaction.

Influence of different photo-activation distances on cytotoxicity of a dental adhesive model resin.

AIM: This study evaluated the cytotoxicity of a dental bonding model resin (DBMR) submitted to different photo-activation distances. METHODS: A monomer mixture based on Bis-GMA and HEMA was used to assess the cytotoxicity in a mouse fibroblast-cell line. To promote different photo-activation distances glass slides were interposed between DBMR surface and halogen light curing unit (LCU) tip. Afterwards, the specimens were immersed in RPMI culture medium for 24 h to obtain extracts. The extracts were incubated in contact with the cells for 24 h. Finally, an MTT colorimetric assay was used to assess the cytotoxicity. The cell viability data (absorbance) were analyzed by one way ANOVA followed by Tukey's test (P<0.05). RESULTS: The light output decreased according to the increase in the number of glass slides between the halogen LCU tip and DBMR surface. Yet, the distance between the tip of the curing light system and the specimens had significant influence on the cytotoxicity. All extracts produced by groups submitted to different photo-activation distances showed cytotoxic effect after 24h of incubation. CONCLUSION: The photo-activation distance and the interposition of glass slides between LCU tip and DBMR was shown to play an important role in the cytotoxic effect.

Sweet Taste Receptor Gene and Caries Trajectory in the Life Course.

This study aims to investigate whether the trajectory of dental caries in the life course is associated with rs307355 (TAS1R3) and rs35874116 (TAS1R2) and if there is an epistatic association between rs307355 (TAS1R3) and rs35874116 (TAS1R2). A representative sample of all 5,914 births from the 1982 Pelotas birth cohort was prospectively investigated, and the decayed, missing, and filled teeth (DMF-T) components were assessed at ages 15 (n = 888), 24 (n = 720), and 31 (n = 539) y. Group-based trajectory modeling was used to identify groups with similar trajectories of DMF-T components in the life course. Genetic material was collected, and rs307355 (TAS1R3) and rs35874116 (TAS1R2) were genotyped. Ethnicity was evaluated using ADMIXTURE. Generalized multifactor dimensionality reduction software was used to investigate epistatic interactions. Considering rs307355 (TAS1R3) in the additive effect, the genotype TT was associated with the high decayed trajectory group (odds ratio [OR] = 4.52; 95% confidence interval [CI], 1.15-17.74) and the high missing trajectory group (OR = 3.35; 95% CI, 1.09-10.26). In the dominant effect, the genotype CT/TT was associated with the high decayed trajectory group (OR = 1.64; 95% CI, 1.14-2.35). Allele T was associated with an increased odds of 64% (OR = 1.64; 95% CI, 1.20-2.25) for the decayed component and 41% (OR = 1.41; 95% CI, 1.04-1.92) for the missing component. No associations were observed between rs307355 (TAS1R3) and the filled component. rs35874116 (TAS1R2) was not associated with DMF-T components. Positive epistatic interactions were observed involving rs307355 (TAS1R3) and rs35874116 (TAS1R2) with the decayed component (OR = 1.72; 95% CI, 1.04-2.84). Thus, rs307355 (TAS1R3) genotypes and alleles seem positively associated with the trajectory of decayed and missing components in the life course. Epistatic interaction between rs307355 and rs35874116 may increase the decayed caries trajectory.

Influence of maternal dental anxiety on the child's dental caries experience.

This study assessed the influence of maternal dental anxiety-related behavior on the child's caries experience. A cross-sectional study with 608 mother-child dyads during the Children's National Immunization Campaign in Pelotas, Brazil was performed. Mothers were asked to answer a questionnaire and dental examination of the children was performed (dmft). The association assessment used Poisson regression. Children from anxious mothers were more likely to present untreated caries even after covariate adjustment. Boys, older children and low-income family children presented a higher dmft mean. Preventive strategies should focus not only on child and family characteristics, but also on maternal dental anxiety-related behaviors.

Caries is the main cause for dental pain in childhood: findings from a birth cohort.

AIM: The aim of the study was to evaluate the prevalence of dental pain in preschool children and its association with socioeconomic, demographic, clinical, and behavior variables. SUBJECTS AND METHODS: The study was nested in a population-based birth cohort from Pelotas, Brazil, started in 2004. A sample of 1,129 children aged 5 years was dentally examined, and their mothers were interviewed. Exploratory variables included demographics, socioeconomic status, mothers' oral health status and associated behaviors, and caries in primary teeth. Data were analyzed using multivariable Poisson regression. RESULTS: The prevalence of dental pain was 16.5% (95% CI: 14.4-18.8). Multivariate analysis showed that dark-skinned children (prevalence ratio, PR = 1.6, 95% CI: 1.1-2.4) from low socioeconomic level (PR 1.9, 1.2-3.0) whose mothers had less than 4 years of education (PR 1.9, 1.0-3.6), from mothers with less than 10 teeth in at least one arch (PR 1.7, 1.2-2.5) and less than 10 in two arches (PR 1.6, 1.0-2.6), and those with high caries prevalence at the age of 5 years (PR 4.8, 3.3-7.1) were more likely to experience dental pain. CONCLUSIONS: Unrestored caries is the main factor associated with dental pain in childhood. Socioeconomic aspects and family context in which dental pain occurs should also be taken into account when dental pain preventive measures are implemented.

Association between black stains and dental caries in primary teeth: findings from a Brazilian population-based birth cohort.

Lower dental caries experience has been observed in children and teenagers with the presence of black stains on dental structures. However, none of the previous investigations were population-based studies or adjusted the analysis for potential confounders. This study assessed the prevalence of black stains at the age of 5 in a population-based birth cohort from Pelotas, Brazil and investigated the association between black stains and dental caries. A total of 1,129 children from the 2004 Pelotas birth cohort were examined at age 5, and their mothers were interviewed at their households. Dental examinations included a search for black stains and dental caries on the primary dentition through the dmf-s index. The mothers' questionnaire comprised data on demographic, social, and behavior aspects. Prevalence of black stains was 3.5% (95% CI 2.5-4.7) and the prevalence of dental caries was 48.4% (95% CI 45.4-51.4). Multivariable logistic regression analysis was performed to assess the association between black stains and dental caries. Adjusted analysis revealed that the presence of black stains was associated with lower levels of dental caries (OR = 0.51; 95% CI 0.26-0.99). The results of the present study suggest that black stains are a protective factor for dental caries development.

Odontoblast RNA stability in different temperature-based protocols for tooth storage.

AIM: To evaluate the effect of four tooth storage temperature-based methods on quality of RNA obtained from cells retrieved from human dental pulps and human pre-dentine. METHODOLOGY: RNA was isolated from dental pulp tissue and from cells retrieved by scraping the pre-dentine of freshly extracted human third molars (n = 15) using TRIzol(®) reagent. Teeth were randomly assigned to the following temperature conditions: immediate RNA isolation after tooth extraction, liquid nitrogen (24 h), -80 °C (24 h), 20 °C (24 h) and 4 °C (6 h). RNA integrity was checked by the density of 28S and 18S ribosomal RNA. RT-PCR was used to analyse the expression of odontoblast makers (DSPP, DMP1 and MEPE) and the housekeeping gene GAPDH. RESULTS: All experimental conditions evaluated preserved RNA integrity. The three odontoblastic markers were amplified from the pulp tissue and from the cells associated with pre-dentine. CONCLUSION: The four storage options allowed RNA isolation for RT-PCR analysis. These findings may facilitate the use of clinically derived human dental pulp and odontoblasts for endodontic research.

Trajectories of Sugar Consumption and Dental Caries in Early Childhood.

This study verifies the association between the trajectory of sugar consumption and dental caries in the 2015 Pelotas Birth Cohort in Pelotas, Brazil. It was conducted with data from the follow-ups at 3, 12, 24, and 48 mo from the 2015 Birth Cohort, which included 4,275 children born alive in hospitals in Pelotas. Data collection included standardized questionnaires for first caregivers applied by trained interviewers at all follow-ups. Exposure was the trajectory of sugar consumption from 3 to 48 mo (always low, always intermediate, increasing, and always high), obtained by group-based trajectory modeling. The outcome of this study was dental caries, obtained through clinical examination performed by calibrated dentists at 48 mo of age. Socioeconomic conditions and oral health instruction from a health professional during the first 4 y of life were included in the analysis as potential confounders. Prevalence ratios and their 95% confidence intervals were provided from generalized estimating equations with a log-Poisson with robust variance specification. In total, 3,654 (91.1%) children participated in the survey at 48 mo, and 2,806 children had complete data for the analyzes performed. Of these, 1,012 (36.1%; 95% confidence interval [CI], 34.3-37.8) experienced caries, and 723 (25.8%; 95% CI, 24.2-27.4) had cavitated caries. Regarding cavitated caries, the prevalence was 1.48 times higher in the group with increasing sugar consumption than children with always low consumption. There is an association between the trajectory of sugar consumption and dental caries at 48 mo. Children with increasing and always high sugar consumption have the highest prevalence of caries.

Can viscosity of acid etchant influence the adhesion of fibre posts to root canal dentine?

AIM: To evaluate the influence of acid viscosity, endodontic sealer and root canal region on the push-out bond strength of a glass fibre post. METHODOLOGY: Seventy-eight single-rooted human teeth were selected (60 for push-out and 18 for scanning electron microscopy characterization, SEM, n = 13 per group). The root canals were prepared with a step-back technique and then filled with Endofill or AH Plus sealer. Teeth without root fillings were used as controls. The preparation of the post-space was to a length of 11 mm using standardized rotary instruments. The root dentine was treated with 37% phosphoric acid (gel or liquid). The fibre posts (Reforpost) were silanized, and resin cement (Enforce) was used for luting procedures. Each root was cross-sectioned, and samples from the cervical and apical regions were subjected to a push-out bond strength test. Specimens from each group were sectioned longitudinally and subjected to SEM characterization for the dentine/cement/post interface. Statistical analysis for push-out tests was carried out using factorial anova followed by Tukey's test (P < 0.05). RESULTS: The three factors under evaluation (acid, endodontic sealer and region) and their interaction significantly influenced bond strength values (P < 0.05). In general, liquid phosphoric acid had significantly higher bond strength values in the apical region (P < 0.05), with hybrid layer formation, while endodontic sealers reduced bond strength values compared to the control (P < 0.05). CONCLUSION: The use of a liquid acid etchant created higher bond strength values in the apical region.

Comparative analysis of two colorimetric assays in dental pulp cell density.

AIM: To compare and contrast two colorimetric assays used for the measurement of proliferation using two dental pulp cell types: dental pulp stem cells (DPSC) and human dental pulp fibroblasts (HDPF). METHODOLOGY: Dental pulp stem cells or HDPF were seeded at 0.25×10(4) cells per well in 96-well plates. Cell proliferation was evaluated after 24-72h. At the end of the experimental period, the sulforhodamine B (SRB) assay or a water-soluble tetrazolium salt (WST-1) assay was performed. Optical densities were determined in a microplate reader (Genius; TECAN). Data were analysed by Student's t-test (comparison between cell types) and one-way anova followed by Tukey test (time-point intervals). Pearson' correlation tests were performed to compare the two assays for each cell line. RESULTS: Both assays showed that DPSC had higher proliferation rates than HDPF. A positive significant correlation between the two colorimetric assays tested for both cell types DPSC (Pearson's correlation coefficient=0.847; P<0.05) and HDPF (Pearson's correlation coefficient=0.775; P<0.05). CONCLUSION: Both tests demonstrated similar trends of cell proliferation, and thus are both appropriate for the evaluation of DPSC and HDPF. The choice of assay is therefore one of the practical applications. SRB stained plates can be dried and stored so may have utility in laboratories where data may require review or when access to analytical equipment is limited. WST-1 assays have the benefit of both ease and speed and may have utility in laboratories requiring either high throughput or rapid analyses.

Histologic response and tenascin and fibronectin expression after pulp capping in pig primary teeth with mineral trioxide aggregate or calcium hydroxide.

This study evaluated the histological response and the expression of tenascin (TN) and fibronectin (FN) after pulp capping with mineral trioxide aggregate (MTA) or calcium hydroxide (CH). Class V cavities and pulp exposure were performed in 40 primary pig teeth. The pulps were capped with either MTA or CH, and the cavities were sealed with resin-modified glass ionomer cement. CH was used as a control. Seven and 70 days posttreatment, the animals were sacrificed and teeth were prepared for histological evaluation. TN and FN were detected by immunostaining. A severe inflammatory response was observed after 7 days in the CH group (p<0.043), while in the MTA group, a mild response was observed. Similar reparative dentin deposition was observed after 70 days for both groups (p<0.005). The expression of FN and TN was similar for both groups in the two periods evaluated. TN and FN were expressed during pulp reparative events, independently of the capping material.

A double blind randomized clinical trial of at-home tooth bleaching using two carbamide peroxide concentrations: 6-month follow-up.

OBJECTIVES: This double blind randomized clinical trial evaluated the longevity of the whitening effect (6-month follow-up) of two carbamide peroxide concentrations used in at-home vital bleaching. METHODS: Ninety-two volunteers with shade mean C1 or darker for the six maxillary anterior teeth were randomized into two balanced groups (n=46) according to bleaching agent concentration: 10% (CP10) or 16% (CP16) carbamide peroxide. Patients were instructed to use the whitening agent in a tray for 2h/day during 3 weeks. Shade evaluations were done with a value-oriented shade guide, and a spectrophotometer at baseline, and at 1-week and 6-month post-bleaching. Volunteers for both treatment groups had to answer questions related to dietary and oral hygiene behavior. RESULTS: At 6-month recall, tooth shade remained significantly lighter than at baseline, in both treatment groups, considering the color parameters: DeltaL, Deltaa, Deltab, DeltaE (p<0.0001) or the tooth shade median values (p<0.001). Additionally, shade median relapse at 6-month follow-up was not statistically different between CP10 and CP16 groups using the spectrophotometer (p=0.1) or the visual matching (p=0.7) analyses. Overall, subjects from CP10 and CP16 reported high consumption of beverage and food stains, which was not different between groups (p=0.5). CONCLUSIONS: The whitening effect remained similar 6-month after the bleaching treatment for both carbamide peroxide concentrations tested. Additionally, the high consumption of staining beverages and foods reported by patients had no influence in the whitening effect longevity at 6-month.

Clinical performance and wear resistance of two compomers in posterior occlusal restorations of permanent teeth: six-year follow-up.

This study evaluated the clinical performance and wear resistance of compomer restorations placed in the occlusal cavities of posterior permanent teeth after six years. In 1999, 72 Class I restorations were placed by a single operator in 33 patients. Eighty-two percent of these restorations were located in molars. Each patient received at least two restorations, one with F2000 (3M ESPE) and another with Dyract AP (Dentsply). The finished and polished restorations that were free of any failure were considered the baseline. The restorations were clinically evaluated at baseline and at one-, two- and six-year intervals using modified USPHS criteria for color mismatch, marginal discoloration, surface roughness, marginal adaptation, anatomic form and secondary caries. Polyvinylsiloxane impressions (Express, 3M ESPE) were also taken, and models were obtained for indirect wear assessment (Leinfelder scale) at the same intervals. After six years, 11 patients attended the recall. Twenty-seven compomer restorations (11 with Dyract and 16 with F2000) were reevaluated. Data were submitted to the Friedman's test, ANOVA with repetitive measures, Tukey's test (clinical data), Wilcoxon and Kruskal-Wallis tests and the Spearman's correlation test (wear evaluation), all at a significance level of p < 0.05. When comparing the materials, F2000 and Dyract presented similar clinical performance and occlusal wear at the end of the clinical trial. The two compomers showed a significant increase in wear at the six-year follow-up, and a positive correlation (r2 = 0.65) was detected between wear and evaluation time (p < 0.001). Despite the decrease in restoration quality and the increase in occlusal wear, nearly all restorations were considered acceptable after the six-year evaluation.

Longevity of Anterior Composite Restorations in a General Dental Practice-Based Network.

This practice-based study investigated the performance of a large set of anterior composite restorations placed by a group of 24 general practices. Based on data from electronic patient files, the longevity of 72,196 composite restorations was analyzed, as placed in 29,855 patients by 47 general dental practitioners between 1996 and 2011. Annual failure rates (AFRs) were calculated, and variables associated with failure were assessed by multivariate Cox regression analysis with shared frailty for 2 age groups (5 to 24 y and ≥25 y). The observation time of restorations varied from 2 wk to 13 y, with a mean of 4.8 y, resulting in a mean AFR of 4.6% (95% confidence interval [95% CI], 4.5% to 4.6%) at 5 y. Among dentists, a relevant variation in clinical performance of restorations was observed, with an AFR between 2% and 11%. The risk for restoration failure increased in individuals up to 12 y old, having a 17% higher risk for failure when compared with the age group of 18 to 25 y (hazard ratio, 1.17; 95% CI, 1.03 to 1.34), and for the age group >65 y, having a 81% higher risk for failure when compared with 25 to 35 y (hazard ratio, 1.81; 95% CI, 1.66 to 1.98). In both multivariate models, there was a difference in longevity of restorations for different teeth in the arch, with fillings in central incisors being the most prone to failure and replacement. It was concluded that anterior composite restorations placed by general dental practitioners showed an adequate clinical performance, with a relevant difference in outcome among operators.