Effect of gap size and cement type on gingival microleakage in Class V resin composite inlays.

Microleakage along the gingival interface was measured in 52 teeth that had received standardized preparations at a fixed depth of 2.0 mm and were restored with Class V composite inlays. Two fabrication techniques and two types of luting cement were compared. Twenty-six teeth were cemented with a resin-modified glass-ionomer cement, and 26 were cemented with a conventional resin cement. Half of the inlay patterns in each cementation group were fabricated directly on the tooth, and half were fabricated indirectly on stone dies. The resin cement was more significantly effective in preventing leakage than the resin-modified glass-ionomer cement. There was no statistically significant difference between inlay fabrication techniques. For those inlays cemented with the resin cement, the mean leakage was substantially lower for the indirect patterns than for the direct group. Although this difference was not statistically significant, it suggests that the slightly larger interfacial gap resulting from the fabrication of indirect patterns is effective in creating a better seal.