Risk Factors for Early Dental Implant Failure.

PURPOSE: To report the prevalence of early implant failure and evaluate factors that contribute to the early failure of dental implants placed at a teaching clinic. The study also aims to identify risk indicators for early implant loss to better predict and prevent early implant loss in the future. MATERIALS AND METHODS: This retrospective study included all patients with a dental implant placed by the Section of Oral Surgery and Oral Medicine, Department of Clinical Dentistry, University of Bergen, between January 2011 and December 2018. All information was collected from operation logbooks and from patient records. A failed implant in this study was defined as an implant lost before functional loading. RESULTS: A total of 1,005 dental implants were placed in the studied time period, of which 54 failed early, giving an early failure rate (EFR) of 5.4%, with functional loading obtained for the remaining 94.6%. Analysis showed an increased hazard for early implant failure among smokers, men, and younger patients. With an age increase of 10 years, the risk of implant failure was reduced by 14% (hazard ratio [HRR] = 0.86, P = .037). A higher failure rate was found in anterior maxillary implants than in posterior maxillary implants (7.79% vs 3.29%, respectively; HRR = 0.47; P = .041). The probability for early failure in the posterior mandible was significantly increased compared to the posterior maxilla (HRR = 3.68, P = .005). If the first implant failed, it was more likely that the consecutive implant would also fail (HRR = 1.82). In the study, 53.4% of the placed implants were Straumann (EFR = 5.2%), 30.3% were Nobel Biocare (EFR = 7.2%), and 16.3% were Astra Tech (EFR = 2.5%). CONCLUSIONS: This study found that younger, male, and smoker patients were associated with an increase in early failure of dental implants. Significantly increased failure rates were also seen for implants placed in the mandible, and there were differences with respect to implant system. Although differences were found in early failure both for patient- and implant-related factors, the overall early failure rate (5.4%) in this study was low.

An 8-10 Year Follow-up of Denture Satisfaction and Oral Health-Related Quality of Life with Implant-Retained Mandibular Overdentures.

PURPOSE: To report changes in denture satisfaction and oral health-related quality of life (OHRQoL) in edentulous patients treated with two-implant mandibular overdentures (IODs) over a follow-up of 8 to 10 years. MATERIALS AND METHODS: This is a follow-up of a previous study carried out between 1997 and 2005. The patients were originally randomly divided into one group receiving IODs and another group who had their conventional mandibular dentures relined (RCD group). The RCD group was offered and received IODs at the 2-year follow-up. The participants completed a self-administered questionnaire containing demographics, 15 variables related to denture satisfaction, and 20 questions from the Oral Health Impact Profile (OHIP-20). Changes over time were analyzed using multilevel linear models for denture satisfaction and multilevel ordinal regression analyses for OHIP-20 variables. Comparisons between groups were analyzed using Mann-Whitney U test for ordinal and t test for metric data. RESULTS: Disregarding patients who passed away during follow-up, the 29 responders represented a response rate of 76%. The degree of denture satisfaction and the OHIP-20 scores remained high and stable in the IOD group over the 10-year observation period for all but one variable. The same factors showed only a modest improvement in the RCD group for the first 2 years; however, during the subsequent 8 years of the observation period (after receiving IODs), denture satisfaction and OHIP-20 scores improved to the same level as the original IOD group. CONCLUSION: The positive effect on denture satisfaction and OHRQoL of edentulous patients treated with two-implant mandibular overdentures remained unchanged 8 to 10 years after treatment.