Tunnel Technique in Bone Augmentation Procedures for Dental Implant Rehabilitation: A Systematic Review

Background/Objectives: This systematic review aimed to compare the tunnel technique for pre-implant bone regeneration with traditional flap techniques also involving a crestal incision, in terms of procedure success, graft healing, postoperative course, patient satisfaction, and implant follow-up. Methods: A systematic search was conducted on MEDLINE/PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials following PRISMA guidelines, searching for comparative prospective and retrospective studies in English, published between January 2002 and April 2024. The population of interest consisted of patients with edentulous ridge atrophy requiring pre-implant bone regeneration. The primary outcome was the success of the procedure. The secondary outcomes included complications, patient comfort, graft resorption, bone gain, primary implant stability, implant success/survival, peri-implant bone level change, and operative time. The risk of bias was assessed using RoB2 and ROBINS-I. Results: The search and selection process yielded one randomized controlled trial and three comparative observational studies, all with serious/high risk of bias. A narrative synthesis was conducted due to the small number of studies and the heterogeneity in key features. The tunnel technique might provide some advantages in terms of the success of the procedure, but the findings were not statistically significant. Conflicting findings or non-significant differences were reported in terms of the secondary outcomes. Conclusions: This review suggested some potential advantages of the tunnel technique for bone augmentation over traditional techniques involving a crestal incision, but the limited quality and amount of data precluded any definitive conclusions.