The use of implant-level connection in screw-retained fixed partial dentures: A 3-year randomised clinical trial

Objectives This randomised controlled trial compares the 3-year outcomes, that is, marginal bone-level (MBL) changes and clinical parameters, between an abutment-level (AL) and implant-level (IL) connection for implants with an internal conical connection (ICC) supporting a screw-retained fixed partial denture. Material and methods Fifty patients with 119 implants were randomly allocated to either the AL or IL group. Radiographic and clinical examinations were performed after one, two, and 3 years. A linear mixed model was used to evaluate the differences between groups. Results The MBL change was not significantly different between the groups at any point. The MBL was 0.12 +/- 0.31 mm (AL) and 0.23 +/- 0.26 mm (IL) after 1 year; 0.15 +/- 0.34 mm (AL) and 0.17 +/- 0.22 mm (IL) after 2 years; 0.18 +/- 0.39 mm (AL) and 0.15 +/- 0.21 mm (IL) after 3 years. The bleeding on probing was 43.44 +/- 39.24% (AL) and 58.19 +/- 41.20% (IL) after 1 year; 35.78 +/- 39.22% (AL) and 50.43 +/- 41.49% (IL) after 2 years; 51.27 +/- 44.63% (AL) and 49.57 +/- 37.31% (IL) after 3 years and was significantly different (p = .025) between 1 and 2 years. The probing depth showed a significant difference at each time point while the plaque was not significant between the groups. The overall technical, biological and prosthetic complication rates were 5.04%, 3.36%, and 16.00%, respectively. Conclusions The MBL change was similar in the groups. The slight differences in the soft tissue complications between the groups are likely not of clinical relevance. An IL connection is considered to be a valid alternative to an AL set-up in ICC implants.