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

Clinical Oral Implants Research. 2023 Jan 27.


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.


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.


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.


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.

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