LAUSR

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 two 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.