Histological evaluation of maxillary sinus floor augmentation with recombinant human growth and differentiation factor-5-coated β-tricalcium phosphate: results of a multicenter randomized clinical trial

Abstract

Objectives: The aim of this prospective, multicenter, randomized clinical trial was to evaluate histologically the outcome of maxillary sinus lift augmentation with a recombinant human growth and differentiation factor-5-coated β-tricalcium phosphate (rhGDF-5/β-TCP) or with a β-TCP and autogenous bone (β-TCP/AB) composite.

Material and methods: Thirty-one patients requiring unilateral maxillary sinus floor augmentation (residual alveolar bone height <5 mm) were randomly allocated in three treatment groups: (a) rhGDF-5/β-TCP and a 3-month healing period, (b) rhGDF-5/β-TCP and a 4-month healing period, and (c) β-TCP and intra-oral corticocancellous autologous bone (at 1:1) and a 4-month healing period. Cylindrical biopsies were harvested by means of a trephine bur during implant site preparation and evaluated histologically and histometrically.

Results: One patient withdrew from the study before implant placement; 66 implants were inserted in the remaining 30 patients. Four out of 47 (8.5%) implants failed in patients treated with rhGDF-5/β-TCP. The proportion of newly formed bone was similar among groups and averaged 31.4% (± 17%) in the rhGDF-5/β-TCP/3-month healing group, 28% (± 15.5%) in the rhGDF-5/β-TCP/4-month healing group, and 31.8% (± 17.9%) in the β-TCP/AB group. The proportion of remaining β-TCP averaged 12.6% (± 14.4%) in the rhGDF-5/b-TCP/3-month group, 6.6% (± 6.3%) in the rhGDF-5/b-TCP/4-month group, and 16.5% (± 12.3%) in the β-TCP/AB group. The new bone was primarily woven and characterized by slender trabeculae and narrow osteoid zones, and in many instances bone was in contact with residual biomaterial particles. Presence of AB particle remnants was only trivial, while minimal amounts of inflammation were observed only in a few cases.

Conclusion: Sinus augmentation with rhGDF-5/β-TCP resulted in comparable amounts of new bone and of similar quality as those obtained with a β-TCP/AB composite graft.