Maxillary sinus lift without grafting, and simultaneous implant placement: a prospective clinical study with a 51-month follow-up.

A prospective clinical study of maxillary sinus lift procedures in the posterior region of the maxilla, using only blood clot as filling material, was conducted. Seventeen patients underwent a maxillary sinus lift procedure; 20 maxillary sinus regions were operated on and a total of 25 implants were placed. The sinus mucosa was lifted together with the anterior wall of the osteotomized maxilla and supported by the implants placed. Computed tomography (CT) scans were obtained immediately postoperative (T initial) and at 3 (T1) and 51 (T2) months postoperative for the measurement of linear bone height and bone density (by grey tones). Only one implant was lost in the first stage (96% success). After dental prosthesis placement and during up to 51 months of follow-up, no implant was lost (100% success, second stage). The difference in mean bone height between T initial (5.94 mm) and T1 (13.14 mm), and between T initial and T2 (11.57 mm), was statistically significant (both P<0.001); comparison between T1 and T2 also presented a statistical difference (P<0.001). Bone density had increased at the end of the period analyzed, but this was not statistically significant (P>0.05). Thus, the maxillary sinus lift technique with immediate implant placement, filling with blood clot only, may be performed with a high success rate.