Evaluation of the Aesthetic Outcome of Implant Single-Unit Restorations with Titanium and Zirconia Abutments Using Aesthetic Indexes - A Pilot Study

Implant single-unit restorations have highly predictable results in terms of osseointegration, but its aesthetic integration frequently constitutes a challenge. This pilot study aims to compare the aesthetic outcome of patients receiving one single-unit implant restoration in the aesthetic zone with zirconia and titanium abutments by means of three of the aesthetic indexes proposed in the literature (PES/WES, ICAI and CIS), in order to understand if there is a correlation between them, as well as which of the abutments has a better aesthetic outcome. The participants (n=16) were submitted to a control visit, in which photographs were taken, a radiograph was collected and information regarding clinical aspects was obtained. The photographs were analysed by 19 external observers and one of the investigators. The correlation between indexes was calculated by the use of the Cohen's k and the internal consistency of the indexes was analysed by the Cronbach's α. There is an accordance between the absolute scores of the indexes, but there is no correlation when the cut-points, that discriminate an aesthetic from an unaesthetic outcome, are employed [PES/WES vs. ICAI (k=0.13)]. Before the same case, the ICAI has a 2.25 (1.96-2.59, 95% CI) higher risk to assign an unaesthetic outcome than the PES/WES. The PES/WES index has the higher internal consistency value (Cronbach's α=0.85). The cases with zirconia abutments were assessed as being more aesthetic than the ones with titanium abutments (p0.05). In conclusion, the PES/WES index appears to be the most consistent, although it lacks aspects related to overall aesthetics, such as the evaluation of the lip line. Within the limitations of this study, the cases with zirconia abutments were considered to have a better aesthetic outcome when compared to those with titanium abutments. However, more studies are necessary. Keywords: aesthetics, implant single unit restoration, titanium abutments, zirconia abutments, Pink Esthetic Score (PES), White Esthetic Score (WES), Implant Crown Aesthetic Index (ICAI), Copenhagen Index Score (CIS), peri-implant soft tissue