Use of self-setting α-tricalcium phosphate for maxillary sinus augmentation in rabbit

Purpose The purpose of this study was to histologically and immuno-histochemically evaluate tissue changes in the maxillary sinus after bone screw implantation and maxillary sinus augmentation using self-setting alpha-tricalcium phosphate (alpha-TCP; BIOPEX (R)-R) in rabbit. Study design Adult male Japanese white rabbits (n=15, 12-16 weeks, 2.5-3 kg) were used. The sinus lift was made from the nasal bone of a rabbit. Bone screws (Dual top auto-screw (R)) were implanted into the nasal bone, and after BIOPEX (R)-R was implanted into the left elevated space (operated side) an atelocollagen sponge (ACS: Teruplug (R)) was implanted into the right elevated space (control side). The rabbits were sacrificed at 4, 12 and 24 weeks postoperatively, and formalin-fixed specimens were embedded in acrylic resin. The specimens were stained with hematoxylin and eosin. For immune-histochemical analysis, the specimens were treated with bone morphogenetic protein-2 (BMP-2) antibodies. Finally, these were evaluated microscopically. Results Tight bonding without fibrous tissue continued between the bone screw and BIOPEX (R)-R, and the rigidity of the bone screw in the nasal bone was retained for 24 weeks in all cases. The area ofnew bone formation increased gradually on both sides; however, there was no significant difference between both sides at 4, 12 and 24 weeks. The number of BMP-2-stained cells on the experimental side was significantly larger than that on the control side after 4 weeks (P=0.0361). Conclusion This study suggested the usefulness of self-setting alpha-TCP (BIOPEX (R)-R) to maintain the rigidity of implanted bone screws from an early period, and the result of BMP-2 expression suggested that BIOPEX (R)-R could have bone-conductive activity in the maxillary sinus augmentation. To cite this article:Marukawa K, Ueki K, Okabe K, Nakagawa K, Yamamoto E. Use of self-setting alpha-tricalcium phosphate for maxillary sinus augmentation in rabbitClin. Oral Impl. Res. 22, 2011; 606-612doi: 10.1111/j.1600-0501.2010.02023.x.