Marginal bone loss and the risk indicators of fixed screw-retained implant-supported prostheses and fixed telescopic-retained implant-supported prostheses in full arch: A retrospective case-control study

Objectives This study compared full-arch screw-retained implant-supported fixed dental prostheses (FSI-FDPs) and full-arch telescopic-retained implant-supported fixed dental prostheses with a professional retrieval system (FTI-FDPs) on marginal bone loss (MBL), the risk indicators and peri-implantitis rate after 7-13 years. Material and methods Sixty five edentulous patients were treated with 86 prostheses and 592 implants. The FSI-FDP group comprised 26 patients (32 prostheses, 202 implants), and the FTI-FDP group comprised 39 patients (54 prostheses, 390 implants). MBL and the risk indicators of MBL >= 1 mm were assessed. Peri-implantitis rates at 13 years were also calculated. Results Full-arch screw-retained implant-supported fixed dental prostheses and FTI-FDP implants exhibited comparable mean MBLs of 0.60 +/- 0.51 and 0.41 +/- 1.03 mm, respectively. MBL >= 1 mm was noted for 25% of FSI-FDP implants and 6.9% of FTI-FDP implants. Superstructure-abutment connection (screw retention:FSI-FDPs >telescopic retention:FTI-FDPs) and implant-abutment connection (External butt joint, Internal butt joint >Morse taper joint) were associated with MBL >= 1 mm. Peri-implantitis rates at the implant level were 3.99% (95%CI = 3.93-20.5) in FSI-FDP group and 3.85% (95%CI = 3.85-34.3) in FTI-FDP group with no significance. Conclusions It was concluded that FSI-FDP and FTI-FDP implants exhibited comparable MBL; however, the risk of MBL >= 1 mm in FTI-FDPs was lower than in FSI-FDPs. Besides, implant-abutment connection was the risk indicator of MBL >= 1 mm. In peri-implantitis rate, FSI-FDPs and FTI-FDPs behave similarly.