COMPARISON OF THE MARGINAL INTEGRITY OF INVIVO AND INVITRO CLASS-II COMPOSITE RESTORATIONS

In the present study Class II resin composite restorations were placed under in vivo and in vitro conditions. For the in vivo part. Class II preparations were cut in teeth destined for extraction for orthodonti c reasons. The preparations were completed with the gingival margin in enamel and restored using six different combinations restorative tech niques and materials. The teeth were extracted after 4-6 weeks. In the in vitro part similar preparations were cut in extracted teeth and re stored using the selected material-technique combinations. The in vitr o specimens were thermocycled and mechanically loaded at 125 N for a t otal of 4000 cycles. All in vivo and in vitro samples were stored in a dye solution, sectioned and inspected for microleakage. Microleakage was observed in all the in vivo specimens with only 60% of the in vitr o specimens demonstrating microleakage. These results indicate the lim itation of laboratory investigations in predicting the microleakage pe rformance of Class II composite resin restorations under clinical circ umstances.