Effect of angulated abutments on stress concentration at the implant abutment interface: a finite element analysis

Background In many clinical situations, there is a difference between the long axis of the implant and the long axis of the planned tooth to be replaced. Such clinical situations led to the advent of angulated abutments. There have been Finite Element Analysis (FEA) studies for analyzing the stress distribution and the pattern of micromotion around the implants when angulated abutments were used, but not much literature is available with respect to stress accumulation at the implant abutment interface. Hence this study is being taken up to analyze the stress concentration at the implant-abutment interface when different angulation of the abutment is used.

Aim To study the stress concentration at the implant-abutment interface with various angulated abutments.

Method and Material Finite element Model assemblies were created to simulate a single implant placed in mandibular posterior region.  Different abutment angulations were tested keeping the length and diameter of the implant fixture constant. Force of 200 N was applied to simulate occlusal force. Von Mises stress was recorded for each model at the implant-abutment interface.

Results As the abutment angulation increased, maximum von Mises stress decreased at the implant-abutment interface.

Conclusion The overall comparison showed as the implant fixture diameter increased the von Mises stress at the implant abutment interface decreased, and suggested that appropriate diameter is essential whenever angled abutments are selected for rehabilitation.