Clinical and radiographic outcomes of implant-supported fixed prostheses with cantilever extension in anterior mandible: A retrospective study

Objectives: The objective of this study is to analyze the clinical and radiographic outcomes of implant-supported fixed protheses with cantilever extensions (ISFPCs) in the partially edentulous anterior mandible. Materials and Methods: Patients who received anterior mandible implant restoration between January 2016 and December 2021 were included. Patients with two, three, or four continuous missing teeth receiving adjacent implant supported single-unit crowns (ISSCs), ISFPCs, implant-supported fixed protheses without cantilever extensions (ISFPNs) were divided into groups: ISSC+ISSC, ISFPC, ISSC+ISFPC, three-unit ISFPN, ISFPC+ISFPC, or four-unit ISFPN, respectively. We recorded and evaluated survival rates, mechanical and biological complications, peri-implant marginal bone loss (MBL), esthetic outcomes, and patient perceptions. Statistical analysis was performed using linear mixed models (LMM). Results: The study included 87 patients and 152 implants. No implant loss occurred during an average follow-up of 3.48 +/- 1.85 years (range: 1-7 years). According to LMM models, prosthetic type had a statistically significant impact on MBL during follow-up periods, in favor of the ISFPC and ISFPC+ISFPC groups (0.16 +/- 0.48 mm vs. 0.51 +/- 0.49 mm, p = .034; 0.22 +/- 0.49 mm vs. 0.60 +/- 0.62 mm, p = .043, respectively). Mechanical and biological complications were relatively low and comparable. The four-unit ISFPC group had higher subjective esthetic scores compared with the ISSC+ISSC group (98.6 vs. 83.8, p < .05), and patients in the ISFPC+ISFPC group expressed greater satisfaction with cleanability than the ISFPN group (98.8 vs. 80.6). Conclusion: ISFPCs offer a highly predictable treatment option in the anterior mandible, characterized by high survival rates, and comparable complication rates, peri-implant bone stability and esthetics to adjacent ISSCs or ISFPNs.