Radiographic Outcomes Of Transcrestal And Lateral Sinus Floor Elevation

Objectives: to comparatively evaluate the extent of bone augmentation obtained at 1 year following either transcrestal or lateral maxillary sinus floor elevation (tSFE and lSFE, respectively) and concomitant implant placement. Particular emphasis was given to the contribution of each intervention to the increase in peri-implant bony support.
Methods: Patients with at least 1 edentulous site with residual bone height (RBH) of 3-6 mm were enrolled in a bi-center, parallel-arm, randomized trial. Both tSFE (Smart Lift technique; Trombelli et al. 2008, 2010) and lSFE were associated with a bovine-derived xenograft, and implants were inserted concomitantly. In lSFE group, the antrostomy was covered with a resorbable collagen membrane. Twelve-month computed tomography or cone-beam computed tomography were used to assess the effect of grafting procedures circumferentially around the implant. Marginal bone loss and maturation of the grafted area were evaluated on periapical radiographs at 6 and 12 months post-surgery. A per-protocol analysis (PP) analysis was performed.
Results: The PP study population consisted of 26 patients in the tSFE group and 28 patients in the lSFE group. At 12 months, the median proportion of the implant surface in contact with the peri-implant radiopaque area (totCON%) was 100% in both groups, with no significant inter-group difference. Suboptimal (< 100%) totCON% was found in 13.0% and 3.6% of tSFE and lSFE cases, respectively, and was mainly due to the absence of a peri-implant radiopaque area in the apical (tSFE group) or palatal (lSFE group) aspect of the implant. In both groups, marginal bone loss was minimal (≤ 1 mm) and infrequent, and the radiographic aspect was suggestive of an advanced stage of maturation.
Conclusions: tSFE (when performed according to the Smart Lift technique) and lSFE similarly contribute to increase substantially the peri-implant bone support at sites with RBH of 3-6 mm at 12 months post-surgery.