One-year clinical evaluation of class II bulk-fill restorations in primary molars: a randomized clinical trial.

This double-blind, randomized clinical trial aimed to compare the clinical performance and clinical time to restore occluso-proximal cavities in primary molars withbulk-fillresin and conventional resin. A total of 140 class II restorations in primary molars of 65 participants (mean age of 6.7 + 1.5) were placed in two random groups:bulk-filland conventional resin. The restorations were evaluated using FDI criteria at the baseline, 6-month, and one year by a single calibrated examiner, and the clinical restorative time was measured with a digital timer. The success and survival of the restorations were evaluated with Kaplan-Meier graphs. The log-rank test compared the curves. Differences in restorative clinical time were compared using the Mann-Whitney U test. The level of significance was 5%. After one year, 115 restorations were evaluated. The success probability was 88.7% for Filtek Z350 XT and 85.9% for FiltekTM Bulk-fill, and for the survival probability, Filtek Z350 XT presented 90%, and FiltekTM Bulk-fill presented 93.7%. No significant difference was found between the success and survival curves (p=0.62), (p=0.51). The main reason for failure was marginal adaptation.Bulk-fillresin required 30% less time than the conventional resin (p<0.001).Bulk-fillresin presented similar clinical performance to the conventional resin and required less restorative clinical time. It is an option to restore class II lesions of primary molars.

Evaluation of the Use of Potassium Iodide Application on Stained Demineralized Dentin Under Resin Composite Following Silver Diamine Fluoride Application.

Purpose: The purpose of this study was to assess the effect of potassium iodide (KI) after applying silver diamine fluoride (SDF) on the staining of demineralized dentin covered or not by a composite resin layer. Methods: Dentin blocks from 30 bovine incisors were demineralized and randomly allocated in three groups (N equals 10): (1) control (no treatment); (2) treated with SDF; and (3) treated with SDF and KI. Half of the specimens of each group received a composite resin restoration immediately after treatment. A colorimetric evaluation, according to the CIE L*a*b* system, was performed at baseline and after seven, 14, 30, and 60 days. The ΔE data were analyzed using the generalized linear model (Δ equals 0.05). Results: The use of KI immediately after applying SDF decreased the dentin staining at all assessment times. SDF treatment only stained the dentin under composite resin after 60 days. The application of KI reduced the dentin under composite resin staining as ΔE values were similar to the control group even after 60 days. Conclusions: The use of potassium iodide minimizes the darkening of dentin and prevents the staining of the dentin under composite resin restorations in the long-term.

Etching time and bonding of adhesive systems to dentin of primary teeth: A systematic review and meta-analysis.

BACKGROUND: Due to the chemical and morphological differences between primary vs. permanent teeth, the time reduction of the acid etching or acidic primer can result in higher values of bond strength. AIM: To assess through a systematic review and meta-analysis the influence of the reducing etching (acid etching or acidic primer) time on the bond strength of adhesive systems to primary dentin. DESIGN: A systematic search was carried out in 3 databases: PubMed, Web of Science and Scopus. Studies that evaluated the effect of reducing the etching time on the bond strength of adhesive systems to primary dentin were included. Meta-analyses were performed using a random-effects model, with subgroups for etch-and-rinse and self-etching adhesives, with a significance level of P < .05. The risk of bias and heterogeneity between studies (Cochrane and I2 tests) were assessed. RESULTS: Eight studies were included in the systematic review and seven in the meta-analyses. The shortening etching time did not influence the immediate dentin bond strength for etch-and-rinse (Z = 0.07, P = .95) and self-etching adhesives (Z = 0.41, P = .69). After ageing, however, the shorting etching time improved the bond strength for etch-and-rinse adhesives (Z = 2.01, P = .04). All studies presented high bias risk. CONCLUSIONS: Reducing the acid-etching time to primary dentin improves the long-term bond strength to this substrate.

Oral health status of schoolchildren living in rural and urban areas in southern Brazil.

This study assessed the effect of area of residence (rural vs. urban) on dental caries experience among southern Brazilian schoolchildren. This cross-sectional survey was conducted in Rosário do Sul, southern Brazil, and included 373 9-14-year-old schoolchildren attending public municipal schools (122 living in the rural area, and 251, in the urban area). Data collection included a questionnaire and a clinical examination. Clinical examination of the permanent dentition involved visible plaque index, gingival bleeding index and dental caries experience (non-cavitated and cavitated, inactive and active lesions). Samples of water were collected to check the fluoride concentration. Caries prevalence and extent using different criteria were compared between rural and urban schoolchildren using the chi-square test and the Mann-Whitney test, respectively. The association between explanatory variables and the extent of caries activity (number of active caries lesions) was assessed using Poisson regression. When caries was recorded at the cavity level (WHO criterion), no difference was observed between rural and urban populations (p ≥ 0.05). Conversely, higher caries prevalence and extent were found among urban schoolchildren when active non-cavitated lesions were also computed (p < 0.05). In the adjusted Poisson regression model, urban schoolchildren were 57% more likely to present more active lesions than rural students (RR = 1.57; 95%CI = 1.29-1.92). Rural communities did not have sufficient fluoride in the water supply, whereas ideal concentrations were detected in the urban areas. In conclusion, this cross-sectional study found that urban schoolchildren showed greater caries experience than rural students, and that this increment was related to active non-cavitated lesions.