In vitro Investigation of Two-body Wear of Human Enamel Compared with Low-fusing Ceramics Fused to Titanium and a Higher-fusing Ceramic

Objectives: The objective of this study was to compare the two-body wear of human enamel to that of the low fusing titanium ceramics Vitatitan, Triceram and Duceratin and the higher fusing ceramic Omega 900. Methods: Intact erupted human molars were loaded in a dual-axis chewing simulator with 40 N for 300,000 chewing cycles. At the beginning a ball of aluminum ceramic as antagonist was put down with a velocity of 0.8 mm/sec and following shifted horizontal for 2 mm. At the end of the shift the antagonist was lifted off and moved back to the starting position. Even grinded samples of Vitatitan, Triceram und Duceratin fused to titanium and samples of Omega 900 fused to a CoCr alloy were loaded according to the same protocoll. For the first 100,000 cycles the volume loss was measured by a 3D-laserscanner in intervalls of 20,000, after that in intervalls of 50,000. Results: After 300,000 cycles Vitatitan showed a mean volume loss 1.00 ± 0.44 mm³, Triceram 1.28 ± 0.63 mm³, Duceratin 0.86 ± 0.23 mm³ and Omega 900 of 1.05 ± 0.34 mm³. These differences turned out to be not significant according to the Mann-Whitney-U-test. Differences between the wear of low fusing ceramics and the higher fusing ceramic were not confirmed by the present two-body-wear investigation. The mean volume loss of human enamel of 0.51 ± 0.23 mm³ on the other hand was significantly lower compared to ceramics (Vitatitan: p = 0.025, Omega 900: p = 0.009, Triceram: p = 0.009, Duceratin: p = 0.025). The mean loss of volume of all samples continously increased to the end of experiment. Conclusions: This investigation of two-body-wear showed less wear of human enamel compared to ceramics. A reduced wear resistance of low fusing ceramics could not be confirmed.