# Clinical audit of Ankylos implant abutment fractures for a ten-year period in practice

## TL;DR

A ten-year audit found a lower-than-expected fracture rate in Ankylos implant abutments, with specific risk factors identified.

## Contribution

The study identifies novel risk factors for abutment fractures in Ankylos implants based on a large clinical audit.

## Key findings

- The abutment fracture rate in practice was 0.6%, significantly lower than the literature average of 2.2%.
- Key risk factors included male patients, first molar sites, and implants opposing natural teeth.
- Implants typically fractured after functioning for about six years.

## Abstract

Introduction Abutment fracture is a clinical problem which can lead to loss of an implant.

Aim To compare abutment fracture rate in the authors' practice against published data and identify any risk factors.

Methods The published literature on the subject was reviewed and a retrospective ten-year clinical audit was conducted to determine the rate of implant abutment fracture for all single-unit, Ankylos, screw-retained implants restored on a titanium base.

Results The abutment fracture rate obtained from the literature was 2.2%, with a specific Ankylos rate of 1.8%. The overall abutment fracture rate in practice during the audited ten-year period was 0.6%, with the following contributing factors identified: male patients (62%), first molar site (84% were at first molar sites), implant restoration opposing a natural tooth (89%), implant bound by another tooth/implant (64%), implant functioning for approximately six years before fracture and a gonial angle of <120°.

Conclusion The fracture rate from the audit was 1.6% lower than that obtained from the literature search and 1.2% lower than that set specifically for Ankylos implants in the published literature. Risk factors were identified which should be considered when planning and consenting cases.

Titanium bases form both the base and the connection to the titanium implant, allowing for integration into the digital workflow and good aesthetics while achieving higher fracture resistance than ceramic abutments.Titanium bases, however, can fracture, with the main risk factors identified in this audit as being: male patients - 62%; implant replacing first molar - 84%; implant opposing natural tooth - 89%; implant functioning in the mouth for approximately six years.This ten-year clinical audit looked at 17,027 single-unit, screw-retained Ankylos implants gleaning a titanium base fracture rate of 0.6%, compared with the published average sample size of 1,207 and rate of 1.8%.

Titanium bases form both the base and the connection to the titanium implant, allowing for integration into the digital workflow and good aesthetics while achieving higher fracture resistance than ceramic abutments.

Titanium bases, however, can fracture, with the main risk factors identified in this audit as being: male patients - 62%; implant replacing first molar - 84%; implant opposing natural tooth - 89%; implant functioning in the mouth for approximately six years.

This ten-year clinical audit looked at 17,027 single-unit, screw-retained Ankylos implants gleaning a titanium base fracture rate of 0.6%, compared with the published average sample size of 1,207 and rate of 1.8%.