INTRODUCTION:Fluoride-releasing restorative materials can be used as a reservoir releasing small amounts of fluoride to the teeth over a long time.Giomer represents a new class of dental materials that uses the pre reacted glass technology (PRG) with excellent mechanical and esthetic properties. OBJECTIVES: The aim of this study is to evaluate the fluoride release ability of Giomer (Beautifil II) compared to Compomer (Dyract XP) and their fluoride recharge ability after exposure to topical fluoride varnish. MATERIALS AND METHODS:The sample consisted of 80 freshly extracted primary anterior teeth. Standardized buccal class V cavities were prepared. Sample was randomly divided into 2 groups: Group I: included 40 teeth restored with Beautiful II. Group II: included 40 teeth restored with Dyract XP following the manufacturer's guidelines. Fluoride release was evaluated in the artificial saliva on 1st, 7th, 14th and 21st days. After 21days of release, 5%NaF varnish was applied on buccal surface of all specimens. The amount of fluoride release after recharge was measured in the artificial saliva after 1st, 7th, 14th and 21st days using fluorine ion-specific electrode. Data were analyzed using Friedman's two-way analysis of variance by ranks, Dunn-Sidak method, Mann-Whitney U test and Wilcoxon Signed Ranks to achieve the aim of the study. RESULTS: Beautiful II released significantly higher amount of fluoride compared to Dyract XP in first 7 days at p<0.0125. Dyract XP released significantly higher amount of fluoride after 14 and 21 days at p<0.0125. After 5%NaF varnish treatment there was no significant difference in fluoride re-release amount of both Beautiful II and Dyract XP at p>0.0125. CONCLUSIONS: Fluoride release (ppm) was found to be significantly higher in Beautiful II than Dyract XP in the first week. Giomer could be considered a suitable class V restoration of primary teeth in high caries risk children.