| Purpose: This study explored the ceramic options for full coverage esthetic restorations in the primary dentition by determining the amount of wear caused by ceramics to opposing enamel in the primary dentition, using an in-vitro model.;Materials and Methods: The localized wear by two different ceramic materials on pediatric enamel was completed using a Leinfelder style in-vitro wear-test apparatus (Dentsply/Caulk, Milford, DE). The entire procedure was carried out to 800,000 cycles, which is equivalent to approximately four years of wear. Eight specimens (n=4) were checked, and the "food", a water slurry of non-plasticized PMMA beads (HG-5, Dentsply/Caulk, mean bead size: 44 microm), changed after each 50,000 cycle run. The maximum wear, height (x-axis), width (y-axis) and depth (z-axis), was measured with a traveling 20X microscope, (Optispec - Micro Enterprises, Norcross, GA).;Results: For zirconia tips, the average X-axis wear was 111 microns; Y-axis wear was 108 microns, and the Z-axis was 15 microns. For alumina tips, the average X-axis wear was 119 microns; Y-axis wear was 110 microns, and the Z-axis was 12 microns. No statistical difference was observed between alumina and zirconia in this wear test (P<0.05) using an ANOVA analysis of covariance.;Conclusion: Although enamel wear was documented in both groups, the amount of in-vitro wear was minimal, suggesting that ceramic crowns can be used without resulting in excessive enamel loss to occluding primary teeth. |
