Marginal soft tissue recession after lateral guided bone regeneration at implant site: A long-term study with at least 5 years of loading.

Abstract

This study evaluated marginal soft tissue recession at implants with simultaneous lateral guided bone regeneration (GBR), at least five years after prosthetic loading. Patients treated with GBR at the time of implant placement and adherent to supportive periodontal therapy (SPT) program with at least 5years of follow-up were re-examined in 5 clinical centers. At the last follow-up, clinical and radiographic data on peri-implant hard and soft tissue were collected. Multilevel analysis considering center, patient, and implant (brand, length, diameter, position) was performed. A total of 96 patients and 195 augmented implants were included. The mean duration of SPT was 8.3±3.1years, while mean recall frequency was 4.5±1.3months. Sixty-five (33%) implants received soft tissue graft before prosthetic delivery. Twenty-one (11%) implants developed biological complications during the follow-up. No implant failure was reported. Mean difference in bone levels (ΔBL) was -0.7±0.9mm, while mean difference in keratinized tissue (ΔKT) was -0.4±0.9mm. Eighty-five (44%) implants showed recession (REC) of soft tissue margin (mean 0.6±0.8mm). The presence of REC was associated with use of non-resorbable membrane (p<.0001) and wider implant diameter (p=.0305), while use of soft tissue graft significantly predicted higher stability of peri-implant mucosal margin (p=.0003). Peri-implant mucosal recession is a common feature 5years after lateral GBR. The risk of recession may be reduced using GBR with resorbable membranes, small diameter implants, and soft tissue grafting before prosthetic treatment.