Spectrophotometric analysis of fluorescent zirconia abutments compared to "conventional" zirconia abutments: A within subject controlled clinical trial

BackgroundZirconia abutments are frequently used for implant-supported single crowns. Even though demonstrating esthetic benefits compared to metal abutments, zirconia abutments lead to an increased brightness of the peri-implant mucosa compared to natural teeth and are not ideal from an esthetic point of view. PurposeTo test whether or not a fluorescent hybrid zirconia abutment offers superior esthetics compared to a non-fluorescent one-piece zirconia abutment based on spectrophotometric analysis. Materials and MethodsIn 24 patients with 24 single-tooth implants, 2 types of reconstructions were fabricated: a directly veneered one-piece zirconia abutment/crown (control) and a directly veneered fluorescent hybrid zirconia abutment/crown (test). Spectrophotometric assessment was performed: prior to abutment insertion (WA), at abutment try-in (A), at the try-in of the final crowns (C). Color differences (E) were assessed compared to the gingiva of natural teeth (T) and between the reconstructions. ResultsAt abutment try-in, E values were 8.493.59 for A(Control) and 8.27 +/- 4.03 for A(Test) compared to T. At crown insertion, E values were 7.61 +/- 4.03 for C-Control and 8.32 +/- 3.57 for C-Test compared to T. The difference in E values between A(Control) and A(Test) was 0.23 +/- 2.54 (P=.37), whereas the difference in E values between C-Control and C-Test was -0.66 +/- 3.45 (P=.48). For all cases with a mucosal thickness 2 mm, the comparison between C-Control and C-Test was significant in favor of the control group (P=.03). ConclusionsBoth types of reconstructions were similar in terms of esthetics. Incases with a mucosal thickness of <2 mm, the soft tissue discoloration compared to the natural gingiva was more pronounced for the fluorescent hybrid zirconia reconstructions.