Purpose: To evaluate healing after sinus floor augmentation at antrostomies prepared with either a drill or a sonic instrument. Materials and Methods: Sinus mucosa elevation was performed bilaterally in 18 rabbits. The antrostomy was prepared with either a drill or a sonic instrument. The elevated space was filled with a collagenated porcine bone, and the access antrostomy was covered by a collagen membrane. The animals were euthanized in groups of six after 2, 4, and 8 weeks of healing. Microcomputed tomography and a histologic analysis were performed. Results: After 8 weeks of healing, remaining defects occupying about 28.9% and 26.0% of the antrostomy were found in the microcomputed tomography analysis. In the histologic analysis, new bone was formed from the margins of the antrostomy, reaching the central region over time. After 8 weeks of healing, 29.1% ± 18.6% and 28.4% ± 15.6% of new mineralized bone was occupying the analyzed zone in the antrostomy at the drill and sonic sites, respectively. Conclusion: The use of a sonic device to prepare the antrostomy resulted in similar healing outcomes in both the antrostomy and the elevated regions. Keywords: animal study, bone healing, histology, morphometry, sinus floor elevation, xenograft