Objectives: To evaluate the influence of abutment disconnections and reconnections on peri-implant marginal bone loss.
Material and methods: Twenty-four participants received single-unit implants and were randomly assigned into one of the two groups: the definitive abutment group (DEF), in which the definitive abutments were connected at the same time as the implant was inserted; and as a control, the healing abutment group (HEA), in which the healing abutments were disconnected and reconnected three times, at 8, 10, and 12 weeks after surgery. Peri-implant marginal bone level was measured through radiographic follow-up performed immediately after the surgery (baseline), at 8 weeks and after 6, 12, and 24 months. Implant stability and peri-implant health were assessed by resonance frequency analysis and peri-implant probing, respectively.
Results: At the end of 2 years, the mean bone level was -0.18 ± 0.12 mm for the DEF group and -0.13 ± 0.13 mm for the HEA group, resulting in a cumulative bone loss of -0.61 ± 0.10 mm and -0.81 ± 0.15 mm, respectively, with no statistical difference between groups. Bone level changes showed statistically significant differences only between 0 and 2 months (DEF: -0.70 ± 0.12 mm; HEA: -0.36 ± 0.10 mm) and between 2 and 6 months (DEF: -0.11 ± 0.11 mm; HEA: -0.65 ± 0.14 mm). No differences were observed between the groups for implant stability, probing depth, and bleeding on probing.
Conclusion: Immediate connection of the prosthetic abutments did not reduce bone loss in comparison with three disconnections of the healing abutments.
Keywords: abutment; dental implants; disconnection; peri-implant bone loss.
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