Marginal changes at bone-level implants supporting fixed screw-retained partial implant prostheses with or without intermediate standardised abutments: 1-year results of a randomised controlled clinical trial.

OBJECTIVE: To compare marginal changes at bone-level implants restored with screw-retained implant prosthesis with or without intermediate standardised abutments, after 1 year of follow-up. MATERIALS AND METHODS: Thirty-six partially edentulous patients received 72 implants. Each patient received 2 implants and a 2- to 4-unit screw-retained implant-prosthesis. The test group received implants consisting of a screw-retained prosthesis connected directly to the implant shoulder, while the prostheses in the control group were connected through a 3-mm standardised intermediate abutment. Clinical and radiological data were recorded at baseline and at 3, 6 and 12 months in follow-up visits. RESULTS: At 12 months, the marginal bone loss was 0.17 +/- 0.24 mm for the test group (19 patients) and 0.09 +/- 0.15 mm for the control group (17 patients), with no statistically significant differences (p > .05). The mean probing pocket depth was 2.96 mm +/- 0.46 for the test group and 2.86 +/- 0.62 mm for the control group. The test and control groups showed bleeding on probing levels of 18.86 +/- 14.12% and 13.73 +/- 17.66%, respectively. All patients scored below 25% on the plaque index levels. CONCLUSIONS: Restoration of bone-level implants with fixed screw-retained partial prostheses with or without intermediate abutments presented similar radiographic and clinical outcomes after 1 year.