Iranian Dental Association Journal of Iranian Dental Association 3060-8201 31 3 2019 07 01 Effect of Finishing and Polishing Time, Technique and Surface Coating on Microleakage of Encapsulated Restorative Resin Modified Glass Ionomer: An In Vitro Study 146 153 10.30699/jidai.31.3.146 EN Fariba Ezoji Ghazaleh Ahmadi Zenouz Adeleh Yousefi Soraya Khafri Journal Article 10.30699/jidai.31.3.146 2020 02 23 2020 02 23 Background and Aim: This study aimed to assess the effect of finishing and polishing time, technique and surface coating on microleakage of encapsulated restorative resin modified glass ionomer (RMGI).<br> Materials and Methods: In this in vitro study, 40 freshly extracted human premolars were selected. Two standard class V cavities were prepared on the buccal and lingual surfaces of each tooth. The prepared teeth were randomly assigned to eight experimental groups (n=10) according to the finishing and polishing time, technique and surface coating. The samples were blindly examined for marginal microleakage using a stereomicroscope at x40 magnification. The Mann-Whitney U test was used to analyze the obtained data with the level of significance set at P<0.05.<br> Results: Groups with surface coating showed significantly lower microleakage than uncoated samples (P<0.001). The groups in which discs were used had lower microleakage (P<0.001). There were no statistically significant differences between the groups with delayed or immediate finishing and polishing (P>0.05). Our results showed that there were no statistically significant differences between enamel and dentinal walls with regard to marginal microleakage scores (P>0.05).<br> Conclusion: Immediate finishing and polishing of coated restorations with Sof-Lex discs decreases their marginal microleakage. Also, it is more effective at the gingival margin.