Keywords : Porcelain fused to metal crown
A comparative evaluation of the effect of various surface treatments on the bond strength of ceramic fused to direct metal laser sintered cobalt chromium alloy- an in-vitro study
European Journal of Molecular & Clinical Medicine,
2020, Volume 7, Issue 8, Pages 4821-4833
Objective: The purpose of the present study was to compare the influence of various surface treatments on the bonding surface of metal laser sintered Cobalt Chromium alloy cylinder and also to analyse the mode of failure in each category. The objectives were to evaluate and compare the bond strength of ceramic over Direct Metal Laser Sintered Cobalt Chromium alloy disc without surface treatment (Group I) and also with various surface treatments including sandblasting (Group II), acid etching (Group III) and laser ablation (Group IV).
Method: Forty samples of Cobalt Chromium cylinders of dimension 12 ×5 mm were fabricated using direct metal laser sintering. The samples were divided into four groups (N=10) samples each based on the surface treatments. After surface treatment, the samples were veneered with porcelain on the treated bonding surface. The shear bond strength test was done using Instron at crosshead speed 0.5 mm/min. The result were statistically analyzed using one way ANOVA Post hoc test followed by Dunnet t test (p<0.05). The mode of failure was also analyzed using Scanning Electron Microscopy.
Result: The mean bond strength of Group II and Group IV were greater than all other groups. The least bond strength was observed for Group III. The SEM analysis showed a cohesive failure for Group II and IV and mixed failure for Group I and Group II.Conclusion: Laser ablation and sandblasting are effective surface treatments for bonding porcelain to Direct metal laser sintered Co-Cr coping.