Long-Term Evaluation of Narrow-Diameter Dental Implants in Posterior Sites in Patients With History of Periodontitis: A Retrospective Study With an 11.5-Year Mean Follow-Up.

Aim: To assess the factors influencing the survival and success rates of narrow diameter implants (NDIs) placed in the posterior area; additionally, the study evaluated marginal bone changes, along with biological and prosthetic complications.

Materials and methods: This retrospective single-center study investigated the clinical and radiographic outcomes of 227 NDIs placed in the premolar and molar regions of 119 patients. The analysis focused on implant survival and success rates, marginal bone levels (MBL), and the incidence of biological and mechanical complications. Generalized estimating equations (GEE) were employed to assess the impact of patient- and implant-related characteristics on these outcomes.

Results: Over a mean follow-up period of 11.51 years (SD: 4.03) the study recorded the loss of 12 NDIs in seven patients. The Kaplan-Meier survival rates were 90.3% (95% CI: 85.4%-95.4%) and 85.7% (95% CI: 77.2%-95.0%) respectively. The average marginal bone loss (MBL) was estimated at -0.75 (SD 1.34) mm. Mucositis was observed in 33.18% of the implants and peri-implantitis in 9.86% of the sample.

Conclusion: This study offers valuable understanding of NDIs as a predictable option in implant dentistry, particularly for patients with challenging anatomical conditions. However, careful case selection and comprehensive treatment planning are crucial to minimize the risk of implant fractures.