Evolution of the Concept of Angulated Abutments in Implant Dentistry:14-year Clinical Data

Abstract

This paper describes the evolution of the concept of selecting the abutment at first-stage surgery and presents clinical data accumulated over 14 years of the use of this concept with angulated abutments. The concept was developed for implants using internal and external hexed connections and has evolved in its use for implants using a Morse taper connection as a result of the considerable clinical advantages that this type of connection offers. A total of 3101 implants were restored using angled abutments ranging from 0 to 45 degrees and were observed over a period of up to 151 months. After an observation time of 120 months (10 years) after placement, the calculated 95% confidence interval of the mean survival estimation, according to Aalen et al, was 98.2% (+/- 0.7%). The magnitude of the angles did not influence the survival rate. The need to refine the implant position in terms of the depth to which it was placed and the angulation and rotational orientation, as well as the size and pivot point of the final abutment, were recognized as contributing to the harmonious emergence profile of the restoration. Good esthetic and functional outcomes were achieved by the use of conventional cement-retained restorations made possible by parallel and aligned abutments.