Alveolar bone remodeling in virtually planned, bone-grafted vs non-grafted guided flapless implant surgery in the anterior maxilla: a cross-sectional retrospective follow-up study

PURPOSE: In patients who underwent virtual planning and guided flapless implant surgery for teeth missing in the anterior maxilla, we compared buccal bone loss between those treated with and without autogenous bone augmentation. METHODS: Of 22 patients with teeth missing because of trauma or aplasia, 10 (18 implant sites) were reconstructed with buccally placed bone graft harvested from the mandibular ramus, and 12 were non-reconstructed (16 sites). Baseline cone-beam computed tomography allowed for implant planning using the NobelClinician® software and was performed again at 1 year after functional loading. The marginal bone level was assessed radiographically at post-implant baseline and at follow-up. RESULTS: At follow-up, buccal bone loss differed significantly between groups at the central level of the implant (p = 0.0005) but not at the coronal level (p = 0.329). The mean marginal bone level change was 0.6 mm, with no significant between-group difference (p = 0.876). The actual implant position often deviated in the vertical or sagittal plane by an average of 0.3–0.6 mm from the planned position. CONCLUSION: Compared with non-reconstructed patients, reconstructed patients experienced significantly more buccal bone loss at the central level of implants. The groups did not differ at the coronal level or in marginal bone loss, possibly because of the more augmented bone at the central level among reconstructed patients. Differences between planned versus actual implant positions should be considered in situations of limited bone volume at the planned implant site.