Effect of abutment types and resin cements on the esthetics of implant-supported restorations

PURPOSE: The aim of the study was to evaluate the optical properties of new generation (3Y-TZP) monolithic zirconia (MZ) with different abutment types and resin cement shades. MATERIALS AND METHODS: A1/LT MZ specimens were prepared (10 × 12 × 1 mm, N = 30) and divided into 3 groups according to cement shades as transparent (Tr), yellow (Y) and opaque (O). Abutment specimens were obtained from 4 different materials including zirconia (Group Z), hybrid (Group H), titanium (Group T) and anodized yellow titanium (Group AT). MZ and abutment specimens were then cemented. L(*), a(*), and b(*) parameters were obtained from MZ, MZ + abutment, and MZ + abutment + cement. ΔE(001)(*) (between MZ and MZ + abutment), ΔE(002)(*) (between MZ and MZ + abutment + cement) and ΔE(003)(*) (between MZ + abutment and MZ + abutment + cement) values were calculated. Statistical analyses included 2-way ANOVA, Bonferroni, and Paired Sample t-Tests (P < .05). RESULTS: Abutment types and resin cements had significant effect on L(*), a(*), b(*), ΔE(001)(*), ΔE(002)(*), and ΔE(003)(*) values (P < .001). Without cementation, whereas zirconia abutment resulted in the least discoloration (ΔE(001)(*) = 0.68), titanium abutment caused the most discoloration (ΔE(001)(*) = 4.99). The least ΔE(002)(*) = 0.68 value was seen using zirconia abutment after cementation with yellow shaded cement. Opaque shaded cement caused the most color change (ΔE(003)(*) = 5.24). Cement application increased the L(*) values in all groups. CONCLUSION: The least color change with/without cement was observed in crown configurations created with zirconia abutments. Zirconia and hybrid abutments produced significantly lower ΔE(002)(*) and ΔE(003)(*) values in combination with yellow shaded cement. The usage of opaque shaded cement in titanium/anodized titanium groups may enable the clinically unacceptable ΔE(00)(*) value to reach the acceptable level.