Longevity of teeth and implants - a systematic review.

The objective of this systematic review was to describe the incidence of tooth and implant loss reported in long-term studies. Prospective longitudinal studies reporting on teeth or implants survival with a follow-up period of at least 10 years were considered. Papers were excluded if the drop out rate exceeded 30% or if <70% of the initial subject sample was examined at 10 years of follow-up. Seventy publications on teeth were identified as potentially relevant for the focussed question. The analysis of the abstracts yielded 37 studies eligible for full-text analysis. The inclusion criteria were met in 11 of the publications that included in all 3015 subjects. The initial search on implant studies generated 52 publications that possibly could be included. Following the evaluation of the abstracts and full-text analysis nine publications were found to fulfil the inclusion criteria. The nine studies included 476 subjects. The incidence of tooth loss among subjects with a follow-up period of 10-30 years varied from 1.3% to 5% in the majority of studies, while in two epidemiological studies on rural Chinese populations the incidences of tooth loss were 14% and 20%. The percentage of implants reported as lost during the follow-up period varied between 1% and 18%. In clinically well-maintained patients, the loss rate at teeth was lower than that at implant. Bone level changes appeared to be small at teeth as well as at implants in well-maintained patients. Comparisons of the longevity at teeth and dental implants are difficult due to heterogeneity among the studies.