Immediate Single-Tooth Implant Placement in Bony Defects in the Esthetic Zone : A 1-Year Randomized Controlled Trial

Background: This study aims to assess, with regard to marginal bone level (MBL), whether the outcome of immediate implant placement in bony defects in the esthetic zone was non-inferior to delayed implant placement after 1 year. Methods: Forty patients with a failing tooth in the esthetic zone and a labial bony defect of >= 5 mm after removal of a tooth were randomly assigned for immediate (n = 20) or delayed (n = 20) implant placement. Second-stage surgery and provisionalization occurred after 3 months of healing. Follow-up was at 1 month and 1 year after definitive crown placement. The study was powered to detect a difference in MBL of >0.9 mm. Buccal bone thickness, soft tissue peri-implant parameters, esthetic indices, and patient satisfaction were also assessed. Results: One year after definitive crown placement, MBL loss was 0.56 +/- 0.39 mm mesially and 0.74 +/- 0.51 mm distally for the immediate placement group and 0.51 +/- 0.43 mesially and 0.54 +/- 0.45 distally mm for the delayed placement group, respectively (not significant). Regarding differences in means, non-inferiority was observed after 1 year (difference in mean for immediate versus delayed: mesially 0.04 mm [95% confidence interval (CI) = -0.22 to 0.30 mm, P = 0.40]; distally 0.21 mm [95% CI = -0.10 to 0.51 mm, P = 0.58]). No significant differences in the other outcome variables were observed. Conclusions: Immediate implant placement with delayed provisionalization was non-inferior to delayed implant placement with delayed provisionalization in labial bony defects of >= 5 mm regarding change in MBL. Although not powered for other outcome variables, no clinically relevant differences were observed in these variables.