Microleakage of posterior composite resin restorations using beta quartz glass-ceramic inserts

The effectiveness of using beta quartz glass-ceramic inserts in Class II composite resin restorations to prevent microleakage at the gingival cementum margins was investigated. Class II cavities were prepared on both mesial and distal sides of ten extracted teeth with the gingival margins placed on cementum. Both cavities were then restored with a composite resin in exactly the same manner, except that one received a glass ceramic insert and the other did not. The specimens were then thermocycled in basic fuchsin solution, embedded in epoxy resin and sectioned. The extent of dye penetration at the gingival cementum margins was then assessed and scored. The result indicated that the use of a glass-ceramic insert substantially reduced the microleakage of gingival cementum margins of composite resin restorations.