Use of self-setting α-tricalcium phosphate for maxillary sinus augmentation in rabbit.
OBJECTIVE
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 α-tricalcium phosphate (α-TCP; BIOPEX(®)-R) in rabbit.


METHODS
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(®)) were implanted into the nasal bone, and after BIOPEX(®)-R was implanted into the left elevated space (operated side) an atelocollagen sponge (ACS: Teruplug(®)) 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, 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).


CONCLUSIONS
This study suggested the usefulness of self-setting α-TCP (BIOPEX(®)-R) to maintain the rigidity of implanted bone screws from an early period, and the result of BMP-2 expression suggested that BIOPEX(®)-R could have bone-conductive activity in the maxillary sinus augmentation.
Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Kanazawa University, Kanazawa, Japan.
Kohei
K
Marukawa
Koichiro
K
Ueki
Katsuhiko
K
Okabe
Kiyomasa
K
Nakagawa
Etsuhide
E
Yamamoto
D020341:Absorbable Implants; D000540:Alveolar Ridge Augmentation / Q000379:methods*; D000818:Animals; D001672:Biocompatible Materials / Q000627:therapeutic use*; D055396:Bone Morphogenetic Protein 2 / Q000032:analysis; D001863:Bone Screws; D018786:Bone Substitutes / Q000627:therapeutic use*; D002130:Calcium Phosphates / Q000627:therapeutic use*; D003094:Collagen / Q000627:therapeutic use; D008297:Male; D008437:Maxilla / Q000473:pathology / Q000601:surgery; D008443:Maxillary Sinus / Q000473:pathology / Q000601:surgery*; D009295:Nasal Bone / Q000473:pathology / Q000601:surgery; D009296:Nasal Cavity / Q000473:pathology / Q000601:surgery; D009297:Nasal Mucosa / Q000473:pathology; D010006:Osteoblasts / Q000473:pathology; D010012:Osteogenesis / Q000502:physiology; D011817:Rabbits; D013997:Time Factors
D001672:Biocompatible Materials; D055396:Bone Morphogenetic Protein 2; D018786:Bone Substitutes; D002130:Calcium Phosphates; C485828:alpha-tricalcium phosphate; C059821:atelocollagen; D003094:Collagen