Background: Understanding the wear behavior of different zirconia types on dental tissues is essential for long-term clinical success. Aim: Abrasion of dental materials, enamel, and dentin is a key complication in clinical practice. This study aimed to investigate the wear of enamel and dentin against polished and polished-then-glazed 3% and 5% yttria-stabilized zirconia (3Y-/5Y-TZP). Methods: Ninety conical samples (4 mm diameter, 7 mm height; n = 9/group) were fabricated from 3Y-TZP, 5Y-TZP, and feldspar ceramic. A total of 10 groups were prepared from feldspar ceramic (18), 3Y-TZP (36), and 5Y-TZP (36). Feldspar ceramics were glazed; half of the zirconia groups of each material were polished, and the other half were polished-then-glazed. Feldspar ceramic, 3Y-TZP, and 5Y-TZP materials were divided into two groups due to the enamel and dentin antagonists. Ninety extracted third molars (45 enamel and 45 dentin) were used as antagonists. Tooth surfaces were scanned with a 3D laser scanner before and after testing. Samples were subjected to 2,40,000 cycles with a dual-axis chewing simulator (50 N, 5°C–55°C). Wear volume (mm 3 ) was measured by superimposing scan data and analyzed using one-way-analysis of variance (ANOVA) with Tukey and Independent Samples t -tests for post hoc analysis ( P = 0.05). Results: Feldspar ceramic showed the highest wear on both enamel (~0.59 mm 3 ) and dentin (~0.48 mm 3 ). All 3Y-TZP groups caused significantly more enamel wear than all 5Y-TZP groups, with 5Y-TZP causing the least wear (~0.13 mm 3 ). Polished samples generally caused less wear than glazed samples, although this was not statistically significant. Conclusion: Within the limitations of this study, the first null hypothesis was accepted as surface treatments (polishing vs. glazing) did not significantly affect wear. However, the second null hypothesis was rejected; zirconia with higher yttria content (5Y-TZP) and polished surfaces are more favorable for minimizing antagonist enamel and dentin wear compared to 3Y-TZP and feldspathic ceramics.
Acar et al. (Sun,) studied this question.