Microleakage, a result of polymerization shrinkage is an important factor affecting the clinical success of the restoration.Toovercome this problem, studies have focussed on factors such as the placement technique and the adhesive system used. The goal of the current study was to determine if the new semi-split filling technique is effective in preventing microleakage at the pulpal floor and the effect of using different generations of adhesive systems on microleakage. Eighty extracted teeth were used and divided into four groups: group 1A: Bulk filling technique with the fifth-generation adhesive system, group 1B: Bulk filling technique with eighth-generation adhesive system, group 2A: Semi split filling technique with the fifth-generation adhesive system, group 2B: Semi split filling technique with eighth-generation adhesive system. Dye penetration method was used to evaluate microleakage under a stereomicroscope. A comparison between the insertion techniques showed that semi split filling technique is effective in reducing microleakage and the eighth-generation adhesive system shows less microleakage than thefifth-generation adhesive system.

Microleakage, Semi Split Filling Technique, Postoperative sensitivity, Bulk Filling Technique, Adhesive system