AN IN-VITRO INVESTIGATION OF THE TOOTH STRAINS ASSOCIATED WITH 4 DIFFERENT RESTORATIONS IN CLASS-II CAVITY

The purpose of this study was to examine tooth strains in Class II pre parations. A Class II cavity was prepared in 16 permanent premolars, a nd a strain gauge was attached to the buccal surface of each tooth. Ea ch cavity was then restored with bonded amalgam, bonded gallium, compo site, or composite with a resin liner. The tooth strains created by th ese four restorations were determined and evaluated with a strain indi cator. The results of this study indicated that composite restorations with and without resin liner created much greater strains to tooth st ructure than did bonded amalgam and bonded gallium restorations. The a pplication of resin liner before placement of the composite was effect ive for decreased tooth strain.