Clinical outcomes of implant- versus abutment-level connection in screw-retained fixed dental prostheses: A 5-year randomized controlled trial

AimThe aim of the study was to evaluate the 5 years clinical outcomes associated with implant-level connection (IL) versus abutment-level connection (AL) for implants with an internal conical connection (ICC) supporting a screw-retained fixed partial denture.Materials and MethodsFifty patients with 119 implants were randomly allocated to either the AL or IL group. Radiographic (Marginal bone loss) and clinical outcomes (Bleeding on Probing, probing pocket depth, plaque accumulation, incidence of peri-implantitis and peri-implant mucositis as well as prosthetic complications) were collected and compared at 1, 2, 3, and 5 years. A linear mixed model was used to evaluate the differences between groups.ResultsFive years after treatment, the MBL change was not significantly different between the groups at any point. The MBL was 0.23 +/- 0.64 mm (AL) and 0.23 +/- 0.29 mm (IL). The bleeding on Probing was 44% (AL) and 45% (IL) (p = .89). The mean probing depth was 2.91 +/- 1.01 mm (AL) and 3.51 +/- 0.67 mm (IL). This difference between the groups was statistically significant but clinical insignificant. Presence of plaque was slightly higher (p = .06) in the IL group (34.4%) compared with the AL group (26.3%). The overall technical, biological, and prosthetic complication rates were similar between groups. None of the implants developed peri-implantitis during the entire follow-up period.ConclusionThe results of this clinical trial indicated that all clinical and radiographical parameters were clinically comparable between the study groups.