Long-Term Effects of Bone Morphogenetic Protein-2–Loaded Calcium Phosphate on Maxillary Sinus Lift Surgery for Delayed and Simultaneous Dental Implantation

Maxillary sinus lift surgery (MSLS) is considered to be a useful treatment method for patients with atrophic alveolar bone. Choosing a suitable surgical procedure to simultaneously decrease graft absorption and obtain long-term survival of dental implants is still a challenge. In this study, 20 patients received MSLS with graft of bone morphogenetic protein 2 (BMP2)-loaded calcium phosphate. Dental implants were placed simultaneously in 10 patients receiving MSLS (1-stage group), and in 10 patients receiving dental implants with a 3 to 6 months delay (2-stage group). The effects were evaluated based on clinical and radiographic examination during a 4 to 5 years follow-up. The results showed that only 1 perforation of the maxillary sinus mucosa was observed in 1-stage group, and was patched with a collagen membrane. An average bone gain of 6.8 mm was observed, and all implants exhibited no looseness, peri-implantitis, or fracture, all of which were stable during the follow-up and exhibited nice dental function during a 4 to 5 years follow-up. The loss of peri-implant bone height was 1.12 ± 0.47 and 1.10 ± 0.39 mm, the probing depth of periodontal pocket was 1.79 ± 0.62 and 1.81 ± 0.71 mm, the sulcular bleeding index was 1.63 ± 0.47 and 1.72 ± 0.54 in 1-stage group and 2-stage group, respectively, and no significant differences existed between these 2 groups. These findings implied that BMP2-loaded calcium phosphate may be a suitable material for MSLS, especially for patients with minimal bone height. Clinicians can use the 1- or 2-stage technique based on clinical condition, patients' choice and clinicians' experience. In patients where implants cannot be stabilized for patients with minimal bone height, 2-stage surgery may be more suitable.