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

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.