Maxillary sinus augmentation by the crestal approach: radiographic changes in graft height. A 1-year retrospective study

Abstract

The purpose of this study is to evaluate, radiographically, the change in intra-sinus graft height after implant placement using inorganic mineral bovine bone and the osteotome technique. Thirty-one implants were placed in twenty-five patients with simultaneous sinus lift using the crestal approach and deproteinized bovine bone ((Bio-Oss®). Periapical radiographs were taken immediately after implant placement, after six months (healing period), and after a minimum of six months of loading. Changes of the graft height were evaluated using image analysis software (Image Tool for Windows, version 3, UTHSCA). The distance between the implant apex and the graft summit was measured along the longitudinal axis of the implant (distance D). This distance was consecutively measured on radiographs taken immediately after surgery (D0), at second stage surgery (D6), and at follow-up visits (D12). Only 25 out of 31 implants were included to analyze the variation in the distance D in time (D6 and D12). Statistical analysis showed a significant difference between D0 and D6 (p<0.0001), between D6 and D12 (p<0.002), and between D0 and D12 (p<0.001). The graft lost 27.4% of its apical height after twelve months. Within the limitations of the present study it was found that the use of deproteinized bovine bone, which has a very slow resorption rate, could not prevent changes in the initially gained intrasinus graft height. However, the reported results showed that its use was beneficial in limiting the loss of the augmented height to a minimum.