Evaluation of Topical Pre-Fluoride Therapy Effects on Marginal Microleakage of Composite Restorations in Deciduous Teeth: An In Vitro Study

Background and Aim: Since fluoride therapy is usually the first step of treatment in pediatric dentistry and it may interfere with other treatments, such as composite filling, this study aimed to evaluate the possible effects of topical pre-fluoride therapy on marginal microleakage of composite restorations in deciduous teeth. Materials and Methods: In this in-vitro study, 30 deciduous canines were randomly allocated to five groups: 1.23% acidulated phosphate fluoride (APF) gel was used in two groups, while 2% sodium fluoride (NaF) gel was used in the other two groups. Thirty minutes and two weeks after fluoride therapy, Class V cavities were prepared and restored using composite resins. After thermocycling, the teeth were soaked in 0.5% fuchsine solution and were sagittally sectioned in half. The extension of dye penetration into the occlusal and gingival walls was investigated under a stereomicroscope at ×30 magnification and scored using a 0-3 scoring system. Data were analyzed using Kruskal-Wallis and Wilcoxon signed-rank tests. Results: Marginal microleakage was neither affected in enamel walls (P=0.213) nor in dentinal walls (P=0.851). The scores of microleakage in enamel walls were lower than that in dentinal walls, and this difference was statistically significant (P<0.05). Conclusion: Topical fluoride therapy using 1.23% APF or 2% NaF gel before the placement of composite resin restorations has no negative effect on marginal microleakage.