Iranian Dental Association Journal of Iranian Dental Association 3060-8201 31 2 2019 04 01 Evaluation of Topical Pre-Fluoride Therapy Effects on Marginal Microleakage of Composite Restorations in Deciduous Teeth: An In Vitro Study 109 116 10.30699/jidai.31.2.109 EN Mina Biria Hasan Torabzadeh Elmira Ghazanfari Atefeh Gohari Negin Eslami Amirabadi Sanaz Kamareh Journal Article 10.30699/jidai.31.2.109 2019 07 08 2019 07 08 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 fill-ing, this study aimed to evaluate the possible effects of topical pre-fluoride therapy on marginal microleakage of composite restorations in deciduous teeth.<br> 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 un-der a stereomicroscope at ×30 magnification and scored using a 0-3 scoring system. Data were analyzed using Kruskal-Wallis and Wilcoxon signed-rank tests.<br> 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).<br> 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.