The use of implant level connection in screw-retained fixed partial dentures: a three-year randomised clinical trial.

OBJECTIVES This randomised controlled trial compares the three-year outcomes, i.e. 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 three 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±0.31mm (AL) and 0.23±0.26mm (IL) after one year; 0.15±0.34mm (AL) and 0.17±0.22mm (IL) after two years; 0.18 ± 0.39mm (AL) and 0.15±0.21mm (IL) after three years. The bleeding on probing was 43.44±39.24% (AL) and 58.19±41.20% (IL) after one year; 35.78±39.22% (AL) and 50.43±41.49% (IL) after two years; 51.27±44.63% (AL) and 49.57±37.31% (IL) after three years and was significantly different (p = 0.025) between one- and two- year. The probing depth showed a significant difference at each time point while the plaque was not significant between the group. 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 setup in ICC implants.