IADR Abstract Archives
Progressive Wear of Graded Zirconia and its Dental Ceramic Counterparts
Objectives: The aim of this study was to evaluate the progressive wear behavior of graded zirconia (polished and as-machined) relative to monolithic zirconia (polished and glazed) and a glass ceramic, as well as their steatite antagonists.
Methods: The wear behavior of polished zirconia, glazed zirconia, polished-graded zirconia, as-machined-graded zirconia and leucite glass ceramic specimens was investigated. The specimens were subjected to sliding wear in a chewing simulator (OHSU) using a steatite ball (r = 3 mm) as the antagonist: maximum load 50 N at 1 Hz for 450k cycles. Quantitative measurements of roughness and wear were performed at baseline, 10, 50, 100, 500, 1k, 10k, 50k, 100k and 450k cycles for the ceramic specimens and steatite antagonists. Damage sustained in ceramic specimens and antagonist was qualitatively analyzed using optical and scanning electron microscopes. ANOVA and Tukey test were used to compare wear and roughness among groups.
Results: Polished zirconia presented little to no variation in roughness and wear depth. Graded and glazed zirconia group presented higher roughness and greater wear depth while the superficial glass layer was visibly present (until 100-500 cycles). The graded zirconia groups presented similar wear depths at 450k cycles, which was shallower than glazed zirconia. The glass ceramic group presented the highest roughness and wear depths throughout the entire study. Continuous increase of antagonist wear depths was observed for all groups. Rough graded zirconia and glass ceramic yielded the greatest antagonist wear, while polished zirconia, polished graded zirconia and glazed zirconia yielded similarly lower antagonist wear.
Conclusions: Polished zirconia and polished graded zirconia presented little wear and roughness, as well as yielded the similarly lower antagonist wear. Feldspathic glass is both more abrasive to the antagonist and more susceptible to wear than zirconia.
Methods: The wear behavior of polished zirconia, glazed zirconia, polished-graded zirconia, as-machined-graded zirconia and leucite glass ceramic specimens was investigated. The specimens were subjected to sliding wear in a chewing simulator (OHSU) using a steatite ball (r = 3 mm) as the antagonist: maximum load 50 N at 1 Hz for 450k cycles. Quantitative measurements of roughness and wear were performed at baseline, 10, 50, 100, 500, 1k, 10k, 50k, 100k and 450k cycles for the ceramic specimens and steatite antagonists. Damage sustained in ceramic specimens and antagonist was qualitatively analyzed using optical and scanning electron microscopes. ANOVA and Tukey test were used to compare wear and roughness among groups.
Results: Polished zirconia presented little to no variation in roughness and wear depth. Graded and glazed zirconia group presented higher roughness and greater wear depth while the superficial glass layer was visibly present (until 100-500 cycles). The graded zirconia groups presented similar wear depths at 450k cycles, which was shallower than glazed zirconia. The glass ceramic group presented the highest roughness and wear depths throughout the entire study. Continuous increase of antagonist wear depths was observed for all groups. Rough graded zirconia and glass ceramic yielded the greatest antagonist wear, while polished zirconia, polished graded zirconia and glazed zirconia yielded similarly lower antagonist wear.
Conclusions: Polished zirconia and polished graded zirconia presented little wear and roughness, as well as yielded the similarly lower antagonist wear. Feldspathic glass is both more abrasive to the antagonist and more susceptible to wear than zirconia.