Purpose: To assess the cumulative failure rate of 4,842 implants comprising six commercial implant brands in a university setting, and to evaluate the influence of different risk factors on the implant failure rate.
Materials and methods: A retrospective chart review was conducted in patients receiving dental implants at the School of Dentistry of the International University of Catalonia (Barcelona, Spain) from 2011 to 2018. The inclusion criterion was patients presenting at least one failed implant.
Results: The cohort study included 1,510 patients who received a total of 4,842 implants. The cumulative failure rate was 4.9% and 10.8% at the implant and patient levels, respectively. The multiple regression analysis showed that for the same number of implants per patient, variables such as age and sex were not associated with higher implant failure rates. Furthermore, in considering the combination of arch-sector, a statistically significant reduction in failure rate was observed in the posterior maxilla (OR = 0.66, P = .038) and in the posterior mandible (OR = 0.64, P = .037). The results showed all implant brands offering high implant survival rates (> 91%). Nobel Biocare and Straumann implants significantly reduced the risk of implant failure (OR = 0.37, P = .021 and OR = 0.53, P = .024, respectively), while no significant differences were recorded among Klockner (2.8%), MIS (5.4%), Biomet 3i (7.1%), and Astra Tech (8.4%; P ≥ .05). No association was found between implant loss and bone augmentation, time of implant placement, smoking, and history of periodontal disease.
Conclusion: The implant failure rates obtained in a university setting resulted in overall cumulative rates of 4.9% and 10.8% at the implant and patient levels, respectively, over a 7-year period. Male sex and implants placed in the anterior mandible may be associated with a higher risk of implant failure. Nobel Biocare and Straumann implants seem to positively affect implant survival rate.
