Augmentation of the maxillary sinus with calcium sulfate: One-year clinical report from a prospective longitudinal study

The aim of the present investigation was to evaluate the clinical and histo logic results of a sinus augmentation procedure performed using calcium sul fate as the grafting material. A group of 12 patients (15 sinuses) formed t he pilot group. Based on the experience of the pilot group, the technique o f calcium sulfate application was modified, and a second group of 45 patien ts (50 sinuses) was subsequently treated (test group). In the pilot group, a total of 30 implants (Biolock) was placed. In the test group, a total of 100 implants (Biolock and Biohorizons) was placed. The clinical data report ed in the present study are related to the 1-year follow-up for both groups . Clinical evaluations, including assessment of implant mobility and probing pocket depth, were recorded on a monthly basis following implant uncovering until final prosthesis placement, and every 6 months thereafter. Radiograp hs were taken prior to sinus augmentation, monthly until 6 months postopera tively, 9 and 12 months after implantation, and at yearly intervals thereaf ter. One implant in the pilot group was not integrated at second-stage surg ery, and 1 in the test group failed to maintain osseointegration after the abutment connection (at the 1-year evaluation). Based on defined criteria, the overall success rate for the 130 placed implants 1 year postimplantatio n was 98.5%. Clinical and radiographic evaluation revealed that the augment ation procedure resulted in new tissue formation within the sinuses. The te chnique used in the test group suggested a slowdown in material resorption and a reduction in graft shrinkage during healing. Bone biopsies were harve sted for histologic evaluation. The application of a resorbable barrier mem brane to the access window reduced the invagination of soft tissue at that level. The results of this study support the hypothesis that calcium sulfat e may be a suitable material for sinus augmentation.