Survival and Risk Factors of Dental Implants in the Anterior Mandible: A Cohort Study

AIM: To evaluate survival and risk indicators of dental implants placed in the anterior mandible in a large cohort. MATERIALS AND METHODS: Patients treated at Maccabi-Dent clinics between 2013 and 2024 who received implants in the anterior mandible (teeth 33-43) were included. Clinical and demographic data were extracted from electronic records. Crude survival rates were compared using chi-square tests; time-to-event outcomes were evaluated using Kaplan-Meier/log-rank and Cox proportional hazards models clustered by subjects, including separate analyses of early (< 1 year) and late (> 1 year) failures. RESULTS: A total of 11 600 implants were placed in 5730 subjects, with an overall survival rate of 97.9% (246 failures) for 4.51 ± 2.8 years. Short implant length (< 10 mm), which consisted of 1374 implants 8 mm in length and only two 6 mm implants, was associated with reduced implant survival. In the multivariable Cox model for overall survival, penicillin allergy and short implants increased the hazard of failure, whereas age ≥ 60 years and long implants (> 11.5 mm) were protective. Early failures were predicted by penicillin allergy, short implants, and male sex, while late failures were primarily influenced by implant geometry and age. CONCLUSIONS: Anterior mandibular implants demonstrated excellent long-term survival. Short implants were consistently associated with higher risk across early, late, and overall failures. Penicillin allergy increased early and overall failure risk, while older age and longer implants were protective. These findings highlight the influence of both patient factors and implant geometry on implant longevity in the anterior mandible; however, these associations should be interpreted with caution, as data on potentially important confounders, including bone grafting materials, surgical protocol, and prosthetic/loading-related factors, were not consistently available.