O tempo de condicionamento ácido influencia a adesão ao esmalte de dentes decíduos? Revisão sistemática e meta-análise

Abstract

The differences in composition and morphology of primary enamel have meant that higher etching times have been suggested in an attempt to favor adhesion to this substrate for a long time. However, although 15 seconds is now standard, there is no uniformity in the literature that this is sufficient to obtain adequate conditioning standards and, consequently, to allow sufficient and lasting adhesion. In pediatric dentistry, the constant search for the reduction of clinical time in order to favor the control of children's behavior and the need for evidence to guide the decision-making process justify this study, which aims to systematically review the literature for laboratory studies that evaluated the influence of different acid etching times on the bond strength of adhesive systems to enamel of primary teeth. The search for laboratory studies was performed in electronic databases (PubMed, Scopus, and ISI Web of Science) using a strategy created by combining specific (MeSH) and free terms without date or language restrictions. Two reviewers independently selected the studies following the eligibility criteria: studies that compared at least two acid etching times and evaluated the bond strength of adhesive systems to primary enamel were selected. Studies that did not present bond strength values as means and standard deviation, did not compare different etching times for the same adhesive system were excluded, as well as those that evaluated the bonding of glass ionomer cement, sealants, or orthodontic brackets. Two reviewers selected the studies, extracted the data, and assessed the risk of bias. The bond strength values were meta-analyzed using a random-effects model, with a significance level of p < 0.05. Heterogeneity (I2 ) was assessed by Cochran's Q test. Of 219 potentially eligible studies, 6 were selected for full-text analysis and 5 studies were included in the systematic review and 4 in the meta-analysis. Acid etching times longer than 15 seconds did not influence the bond strength of adhesive systems to deciduous enamel (Z=0.02; p=0.98). Heterogeneity was moderate (I2=49%; p=0.10). All studies presented a high risk of bias. Based on the results obtained, it can be concluded that the acid etching time of 15 seconds seems sufficient to promote bond strength values of adhesive systems to the enamel or primary teeth similar to longer times.