Effects of Dicalcium Phosphate Composite Graft in Bone Regeneration for Peri-Implant Bony Defect: Animal Study

• Main Authors: Kang-Kuei Fu, 傅康貴
• Other Authors: Chun-Pin Lin
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/8g5us5

碩士 === 國立臺灣大學 === 臨床牙醫學研究所 === 101 === Using particulate form calcium phosphates as the biosynthetic materials has become popular in clinical practice. Although the particulate form calcium phosphates are easily to fill small bony defect, however, their insufficiency in strength lead to instability of the graft and poor space maintenance of defect which result compromised efficacy in alveolar bone regeneration, especially in large alveolar bone defect. Thus many combinations of different forms of calcium phosphates have been proposed to overcome insufficiency of strength in grafts. Recently, a new bone block constitutes with mainly dicalcium phosphates and partially hydroxyapatites with sufficient strength and adequate resorption rate has been developed. The purpose of this study is to evaluate efficacy of new bone formation of such new developed bone block in large peri-implant alveolar bony defect in animal model. In this study, we use three beagle dogs, weighing between 7 kg to 10 kg, distribute to three groups as following: 1. experimental group (n = 7) which using the bone block containing dicalcium phosphates and hydroxyapatite (DCPD+ HA) as graft in defect; 2.control group A (n = 6) which using the collagen enhanced particulate biphasic calcium phosphate(hydroxyapatite and β-tricalcium phosphate with collagen (HA+β-TCP+collagen)) for defect repair; 3.control group B (n = 5) which without any bone graft (blood clot only) in defect. In this experiment, the extraction of four mandibular premolars and one first molar at bilateral mandible was done in the beginning. Following six weeks healing, the implantation over the mandible with bony defect preparation and guide bone regeneration would be preceded with test bone grafts or without any grafts randomly. The operations are performed at different time points (4-week, 8-week and 12-week) before the animal’s sacrifices. At the time of operation, the implantation was performed simultaneously with the measurements of implant stability using resonance frequency detector. We also injected the bone labeling fluorescence subcutaneously at the time point 4-w and 2-w before the animal’s sacrificed for evaluation of the area and amounts of new bone deposition with inverted fluorescence microscope. After sacrificing, the use of implant stability quotient analysis, radiographic analysis, histological analysis, CT scan analysis and bone labeling technique were performed to evaluate the new bone formation and osseointegration at the bony defect around the eighteen implants. Results of this study revealed that the efficacy of new bone formation and osseointegration of the experimental group (DCPD+HA) are better than control group A (HA+β-TCP+collagen) and control group B (blood clot only), whether in the quantity and the quality of new bone or the speed of new bone formation. Statistical significant differences among different groups can be shown in peri-implant bone coverage ratios at 8-w following surgery. Moreover, significant statistical differences can also be shown in implant stability quotient values, radiographic peri-implant bone coverage ratios, histological peri-implant bone coverage ratios, CT bone mineral density at 12-w following surgery. In addition, the bone labeling technique proved similar pattern of healing among the three groups, however, the speed of new bone formation of the experimental group (DCPD+HA) is significantly higher than the other two control groups. In present animal study, healing pattern and clinical efficacy in the new dicalcium phosphates and hydroxyapatite bone block has been throughout investigated and evaluated, furthermore, such a new dicalcium phosphates and hydroxyapatite bone block has showed promising efficacy in bone regeneration as compare to commercial calcium phosphates.