In vivo wear pattern of experimental composite resins based on different resin monomers.

This study investigated the effects of various monomer systems on composite resin wear in vivo. Experimental light-cured composite resins were prepared employing four different monomer systems: (1) Bis-GMA type, (2) D-2. 6E type, (3) UDMA type, (4) UTMA type. The resin monomers consisted of 70wt% main monomer and 30wt% TEGDMA. These composites contained 80wt% fine quartz. The resins were placed in 2 mm diameter cylindrical cavities located in the occlusal contact area or the contact free area in cast crowns, temporarily set in a mouth. The crowns were removed at monthly intervals, for longitudinal SEM observation. Two months after setting, wear was analyzed, using an electron probe surface roughness analyzer. Microabrasion of the resin matrix and loss of filler particles were observed for all types of monomer systems. The effect of matrix resin systems on occlusal wear was smaller than that of filler systems.