Immediate vs early loading of 6.6 mm flaplessplaced single implants: 9 years after-loading report of a split-mouth randomised controlled trial

Purpose: To evaluate the long-term effectiveness of 6.6 mm long flapless-placed single implants loaded immediately or early loaded at 6 weeks. Materials and methods: Thirty patients each received two single Nanotite External Hex Biomet 3i implants, which were then randomly allocated to be either immediately or early loaded, according to a split-mouth design. Implants had to be inserted with a torque superior to 40 Ncm. Provisional crowns were put in slight occlusal contact and replaced by definitive crowns 3 months after loading. Patients were followed for 9 years after loading. Outcome measures were implant failures, biological and biomechanical complications, peri-implant marginal bone level changes and patient preference. Results: A total of 29 implants were immediately loaded, while 31 were early loaded. Nine years after loading, three patients dropped out. One implant failed in each group within 2 months after loading. One patient asked for the immediately loaded crown to be remade for aesthetic reasons and then again to have both metal-ceramic crowns replaced by full ceramic crowns. Another patient had his immediately loaded crown remade after repeated debonding. Six patients from each group experienced complications, the difference being not statistically significant (difference of proportions = 0.00; 95% CI -0.20 to 0.20, P = 1.000). Peri-implant bone loss was 0.60 mm for patients with immediately loaded implants and 0.46 mm for early loaded ones, which was not significantly different (mean difference = 0.14 mm, 95% CI -0.13 to 0.41, P = 0.283). All but one patient had no preference for either procedure after 9 years. Conclusions: Flapless-placed 6.6 mm long single implants can be immediately loaded and remain successful up to 9 years after loading. Conflict-of-interest statement: This study was initially supported by a grant from Biomet 3i, which also provided free implants and related prosthetic components. Zimmer-Biomet then decided that this study was of no interest and stopped their funding, so the study became completely selfsupported. Data property always belonged to the authors and by no means did the manufacturer interfere with the conduct of the trial or the publication of its results.