In vivo studies of poor crystalline hydroxyapatite based biphasic calcium phosphate bone grafts

• Main Authors: Chih-Yuan Hu, 胡致遠
• Other Authors: 楊正昌
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/47841662053520203656

碩士 === 臺北醫學大學 === 口腔科學研究所 === 95 === Bone substitute materials are widely used to accelerate healing process while suffering large bone defects in orthopedic and dental clinics. Commercial biphasic calcium phosphate (BCP), containing hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP), is a widely used synthetic bone graft with the shortcoming of prolonged resorption time. In this study, poor crystalline hydroxyapatite (PC-HA) and β-TCP were mixed in different ratios to investigate which mixing ratio could be adapted to the resorption rate of clinical application for dental bony defect. After preparing PC-HA and β-TCP by wet chemical precipitation method separately , granular type bone grafts were collected by filtrating, freeze drying, tableting, sintering, mixing, and size screening. All the bone graft specimens were analyzed with scanning electric microscope (SEM), Fourier transform infrared spectrometer (FT-IR) and X-ray diffraction (XRD). Prior to the implantation experiments, all premolars of 4 beagles were extracted. After 16 weeks of healing period for stabilizing the wound sites in alveolar bone, 8 cylinder type of artificial bony defect (3 mm diameter, 6 mm length) were produced, and filled with disinfected BCP of (PC-HA/β-TCP= 70/30, 60/40, 0/100) as experimental groups and commercial products of MBCP® (HA/β-TCP= 60/40), Cerasorb®(β-TCP=100%), and empty defect as control groups. The cylinder type bone blocks (5 mm diameter, 8 mm length) were brought out at 8 weeks postoperatively for histological studies. There are significant differences of new bone formation ratio between all experimental and control groups (one-way ANOVA, P < 0.05). The results of Duncan multiple range test also showed significant differences between treatment groups compare to empty control groups, PC-HA/ β-TCP=70/30 to β-TCP, and PC-HA/ β-TCP=60/40 to β-TCP groups. Comparison of the coefficient variation (CV), the distribution in experimental groups of new bone formation show better evenness than groups of MBCP®, Cerasorb®, and empty controls. The results showed that BCP of experimental groups and commercial products are biocompatible and the healing effects are better than unfilled empty control groups, indicating BCP of PC-HA/β-TCP is a new choice for bone defects filling.