Implant failures and age at the time of surgery: A retrospective study on implant treatments in 4585 edentulous jaws.

BACKGROUND: There is limited knowledge on the relationship between implant failures and patient age at implant surgery.

PURPOSE: To further analyze and report long-term data on previously presented significant associations between implant failures and age at surgery in patients receiving treatment in the edentulous jaw.

MATERIALS AND METHODS: A total of 4049 patients were provided with 24 781 implants during 4585 operations in edentulous jaws between 1986 and 2015 in one referral clinic. Patients were thereafter invited to be followed up until the termination of the study. All implant failures were recorded, and nonlinear spline statistical methods and calculations of survival curves for different age groups were used to analyze implant failures related to age at surgery.

RESULTS: Ten-year age groups presented consistently higher overall survival rates with increasing age. The overall 10-year survival rates for treated jaws without failures ranged between 83.4% and 91.0% for different age groups. The risk of implant failures in 50-year-old patients was higher than in older patients within 15 years of follow-up (66/78 years; P < 0.05). The difference between young (<45 years), middle-aged (45-64 years), and old (>64 years) patients became more pronounced in patients included later in the study (2003-2015).

CONCLUSIONS: Young edentulous patients presented an overall significantly higher risk of implant failure than did old patients. The risk decreased consistently from patients in the youngest age group (30-39 years) to those in the oldest age group (>79 years), with a more pronounced pattern for the patients included in the late period. This finding suggests a change in patient characteristics during the time of inclusion, but no causal explanations for the present observations have been established.