Clinical Outcome of One Step Implant Therapy in Severely Atrophic Posterior Maxilla: A 4-16 Year Retrospective Study.

Purpose: This long-term retrospective case series study aimed to evaluate the efficacy and to identify risk factors for peri-implantitis associated with the one-step lateral sinus floor elevation (LSFE) procedure in patients with a severely atrophic posterior maxilla.

Materials and methods: Clinical data were obtained from Periodontic Department at Taipei Tzu Chi Hospital. One-step, non-submerged LSFE enabled simultaneous implant placement in sites with residual bone height < 5 mm. In total, 54 patients and 65 sinuses received 107 implants to support fixed reconstructions over a period of 4-16 years. Healing abutments were simultaneously placed at the time of fixture placement. Clinical and radiographic outcomes were assessed, including marginal bone loss (MBL) and implant survival rate. Information on implants and patients was recorded. Univariable and multivariate analyses were performed through the generalized estimating equation method to assess possible patient- and implant-related risk factors for MBL and peri-implantitis.

Results: The overall implant survival were 97.2%. Twenty-nine implants (27%) had MBL > 0.5 mm. A history of periodontitis was not significantly associated with MBL (p > .05). Patients with poor oral hygiene (p < .001), diabetes (p = .010), or width of keratinized mucosa < 2 mm (p = .011) were identified as potential risk factors for peri-implantitis.

Conclusion: This study demonstrates that with careful case selection and adherence to proper implant protocols, one-step implant placement in severely atrophic maxillary sinuses using the LSFE is predictable and can be maintained long-term.