Effect of varnishes on surface microhardness of basing materials

This study investigated the surface microhardness of five basing materials with four varnishes applied to them. Ten Plexiglass molds with 7-mm diameter holes were prepared. Basing materials of Cavitec, Life, Ketac Bond, TimeLine, and Cavalite were placed in the molds to produce 20 samples each. Copalite, Universal, Contact, and Barrier varnishes were applied to the top and bottom surfaces of the base material samples at 1 hour and 24 hours. After air drying, the surface microhardness of the samples was tested with a Micromet II microhardness tester. The surface microhardness of all the basing materials tested was reduced when varnishes were applied to them. Contact and Barrier reduced surface microhardness value more than Copalite and Universal.