Effects of high temperatures on different dental restorative systems: Experimental study to aid identification processes

Abstract

This in vitro study was to observe the effects of high temperatures on teeth restored by (1) amalgam overlaying glass ionomer bases, (2) composite/adhesive system overlaying glass ionomer bases, (3) ZnO modified temporary filling material vs. unrestored teeth. Fifty un-restored teeth (control group), 50 teeth with class I amalgam restorations and glass ionomer bases, 50 teeth with class I composite/adhesive system restorations and glass ionomer bases and 50 teeth with class I ZnO modified temporary filling material restorations were placed in a furnace and heated at a rate of 10°C/min. The effects of the predetermined 200, 400, 600, 800, 1000 and 1200°C temperatures were examined macroscopically and then observed microscopically by means of a stereomicroscope. Our observations showed that the class I restorations made of amalgam on glass ionomer bases as far as the class I restorations made of ZnO modified temporary filling material can be identified till 1200°C because they maintain their shape despite the disintegration of the crowns, whilst the class I composite/adhesive system and the underplayed glass ionomer bases remained in place in an altered shape.