Shade Outcome of 3Y, 4Y, 5Y Monolithic Zirconia on Colored Annodized Titanium

OBJECTIVES: Zirconia has become a restorative material of choice on implant supported restorations due to its ability to obscure discoloration of metal abutments. This project observed if anodization of a titanium abutment minimizes the effect on the final restoration shade and if yttria content is correlated with the stability of the resultant shade. METHODS: Six titanium abutments were milled based on a specific design and annodized at variable voltages: unanodized, 11V (bronze), 31V (blue), 54V (green), 64V (yellow), and 76V (pink). Sixty A2 monolithic zirconia crowns of 3Y, 4Y, and 5Y (Dentsply Sirona Cercon HT, IPS ZirCad MT, and Dentsply Sirona Cercon XT) were designed with 1mm measured uniform thickness over the titanium abutment. Spectrophotometer measurements were obtained on a control sample, and again over each abutment color. The ΔE00 was calculated for each sample for each abutment color/voltage. RESULTS: One way ANOVA for each sample set of 3Y, 4Y, and 5y zirconia materials found a highly significant (p<.0001) difference between different anodized abutments. For all samples, blue showed the highest mean ΔE00 values which were significantly higher than all five groups (P<.0001). The lowest mean ΔE00 for 3Y samples was unanodized titanium (p<.05). The lowest ΔE00 for 4Y and 5Y samples was yellow (p<.05). No pairwise comparisons were significant (p>/=.26). A two-way ANOVA found no significant difference amongst type of material (p=.048). CONCLUSIONS: Significant differences in shade were found utilizing varying voltages of anodized custom abutments. The yttria content of the zirconia had no overall effect on shade when placed over varying voltages of anodized custom abutments. IMPLICATIONS: This study provides information on whether anodized titanium custom abutments under monolithic zirconia restorations influence the overall shade. This study provides recommendations regarding material choices and how different yttria content or translucencies of zirconia can alter the esthetic outcome of a final restoration.