Microleakage of self- adhesive resin cements compared withresin cements containingetch&rinse adhesives

Current self-adhesive resin cements have become popular for esthetic restorations. The purpose of this study was to compare the microleakage of 2 self-adhesive resin cements and 2 etch and rinse versions of the same brands. Forty human third molars were randomly assigned to 4 experimental groups: 1-Rely X Unicem، 2- Rely X ARC+ Acid etch 37% + Single Bond، 3- Nexus 3 Acid etch 37% + Optibond Solo، and 4- Maxcem Elite. Microleakage of the specimens were then measured with a four point scoring system at both the cervical &occlusal areas، with the aid of a stereomicroscope. Microleakage scores were compared using Kruskul-Wallis analysis، followed by relative Dunn test. The microleakage of Rely X Unicem and Nexus 3 were significantly less in the occlusal region (P<0. 05)، whereas in the cervical area there was no significant difference in microleakage between Rely X Unicem and Rely X ARC (P= 0. 0087). The microleakage of Nexus 3 was significantly less than that of Rely X Unicem. Maxcem Elite showed the highestlevel of microleakage (P<0. 05). Microleakage of both cements using etch & rinse adhesive systems were significantly lower in comparison withtheir self- etch counterparts both at the cervical &occlusal areas. (P< 0. 05) Key words: