A new index for rating aesthetics of implant-supported single crowns and adjacent soft tissues - the Implant Crown Aesthetic Index

Objectives: The important item of aesthetics is rarely included in evaluation studies. The aim of this study was to develop and validate an index for rating aesthetics of implant-supported single crowns and adjacent soft tissues. Material and methods: Nine items were selected, which have an influence on the aesthetic result. The items are based on the anatomic form, colour and surface characteristics of the crown and on the anatomic form, colour and surface characteristics of the peri-implant soft tissues. Two oral-maxillofacial surgeons and two prosthodontists rated 24 implant-supported single-tooth restorations and adjacent soft tissues on a form with the nine items of the rating index. The rating was carried out twice by each of the examiners. Weighted Cohen's kappa was calculated to express the intra- and interobserver agreement. Results: Intraobserver results indicated that the agreement between the first and second rating of both the prosthodontists was good (both 0.7) and that the agreement of the oral-maxillofacial surgeons was moderate (0.49 and 0.56). The best interobserver agreement was found between the two prosthodontists (0.61, good agreement). Conclusions: The Implant Crown Aesthetic Index is an objective tool in rating aesthetics of implant-supported single crowns and adjacent soft tissues. The rating is best be carried out by one prosthodontist to have the highest reliability.