Comparison of Healing Outcomes Between Simultaneous and Staged Implant Placement With Sinus Floor Elevation: A Preclinical Study Using a Rabbit Sinus Model

Aim: To compare the histological healing between implants placed simultaneously with maxillary sinus floor augmentation (MSFA) and those placed with a staged approach in the maxillary sinus with thin bone height. Materials and methods: MSFA was performed on both sides of the sinuses in 10 rabbits, followed by simultaneous implant placement in one of the sinuses (group SMT). Four weeks later, implant placement was performed in the other sinus (group STG). The animals were euthanised 8 weeks thereafter. Micro-computed tomographic and histomorphometric analyses were performed. Results: In micro-computed tomographic images, the implants were well surrounded by newly formed bone (NB) and bone substitute particles, without statistically significant difference in the volume of NB between the groups (p > 0.05). Histomorphometrically, the amount of NB within the total augmented area and ROIs near the implants did not significantly differ between the groups (p > 0.05). The percentage of bone-to-implant contact was not significantly different between the groups (52.2% ± 16.6% vs. 44.9% ± 18.4%; p > 0.05). Conclusions: Simultaneous implant placement with MSFA resulted in comparable radiographic and histological outcomes to a staged implant placement approach in sinuses with thin bone height. However, such outcomes should be cautiously interpreted within the context of an animal model.