Surface Treatment on Superficial Roughness and Microhardness of Zirconia-based Ceramic

Objective: The use of ceramic materials has shown emphasis in oral rehabilitation. Among these are systems based on zirconia, which has satisfactory outcomes related to mechanical strength, biocompatibility and biofilm formation, and a favorable option for rehabilitation of posterior regions. The challenge of this material is to obtain an effective adhesion of resin cements to ceramic, requiring alternative means of ceramic surface treatment in order to ensure an adequate adhesive cementation. The objective of this study was to evaluate the influence of different surface treatments on the microhardness and surface roughness of zirconia-based ceramic. 

Method: Twenty-five zirconia blocks (LAVA-3M) (8x8x3mm) were obtained and divided into five groups (n=5) according to surface treatment. Group N- no treatment; Group B – Al2O3 blasting; Group BP - Al2O3 blasting/primer MDP; Group SS - silica coating/silane and Group SP – silica coating/primer MDP. After the surface treatment, microhardness and surface roughness tests were performed  and means were calculated and submitted to statistical analysis using ANOVA one way test (p<0.05).

Result: The results for microhardness (Knoop) were Group N=1319.33(B); Group B=1918.06(A); Group BP=1844.86 (A); Group SS=1857.86 (A) and Group SP=1836.06(A). The results for surface roughness (Ra) were Group N=0.10(C); Group B=0.37(B); Group BP=0.43(A); Group SS=0.46(A) and Group SP=0.48(A). Capital Letters indicate statistical differences.

Conclusion: Based on the results, can be concluded that with respect to microhardness, all surface treatments increased microhardness values, with no significant statistical difference among the treatments. With respect to surface roughness, all treatments increased surface roughness values, while group B showed the smallest change in roughness when compared to other groups with surface treatment (BP, SP and SS) which showed no difference between them.