Document Details

Document Type : Thesis 
Document Title :
Effect of Hyperbaric Oxygen on Healing of Bone, Bone Grafts, and Bone Graft Subtitutes in Calvarial Defects
تأثير الأكسجين عالي الضغط على التئام العظام وزرعها وترميمها وبدائلها في العيوب ذات الحجم الحرج في الجمجمة
 
Subject : Tissue Engineering, Oral and maxillofacial Surgery 
Document Language : English 
Abstract : This study was undertaken in four phases to evaluate the effect of hyperbaric oxygen (HBO) on the repair of critical-sized defects in the presence and absence of a nonvascularized autogenous bone graft (ABG) and bone graft substitutes namely, demineralized bone matrix (DBM) combined with Pluronic F127 (F127) to form a gel or putty, or a commercially available biphasic calcium phosphate (BCP), mixed either with blood or F127 to form a putty. A total of 50 New Zealand white rabbits were utilized in this study. Phase I utilized 20 animals which were randomly divided into 2 groups of 10 animals each. Calvarial defects were created in the parietal bones of each animal bilaterally. Defects were critical-sized, 15 mm on one side and supracritical-sized, 18 mm on the contralateral side. Group 1 received 90-min HBO treatment session at 2.4 absolute atmospheric pressure (ATA) per day for 20 consecutive days. Group 2 served as normobaric (NBO) controls, breathing only room air. Five animals in each group were sacrificed at 6 and 12 weeks. In phase II 20 specimens that were harvested in phase I were analysed for the presence of Vascular Endothelial Growth Factor (VEGF) expression using immunohistochemical staining. Phase III utilized an additional 10 animals which were randomly divided into 2 groups of 5 animals each. Bilateral 15 mm calvarial defects were created in the parietal bones of each animal. ABG were allocated to the left or right defect of each animal. Group1 received HBO treatment while Group 2 served as NBO controls. All animals were sacrificed at 6 weeks. In phase IV an additional 20 animals were used which were randomly divided into 2 groups of 10 animals each. Bilateral 15-mm calvarial defects were created. Group I defects were grafted with either DBM putty or DBM gel. Group II defects were grafted with either BCP or BCP putty. Five animals from each group received HBO treatment and 5 animals served as NBO. All animals were sacrificed at 6 weeks. Calvarial specimens were analysed by plain radiography, micro-computed tomography (mCT) and histomorphometry. Both radiographic analysis and histomorphometric analysis demonstrated more new bone within HBO-treated defects compared to NBO defects (p<.001). There was no significant difference between the percentage of new bone forming in the 15-mm and 18-mm HBO-treated defects. VEGF expression in 6 week HBO samples was elevated compared to NBO (p=0.012). Staining of the 12 week HBO samples was reduced compared to 6 week HBO (p=0.008) and was similar to 6 and 12 week NBO samples. HBO reduced fibrous tissue formation in BCP grafted defects and promoted a small but significant increase in bone formation in DBM grafted defects. mCT analysis indicated a higher bone mineral density (BMD) and bone mineral content(BMC) in ABG than Non-Grafted defects (p<0.05). Higher BMC (p>.05), bone volume fraction (BVF; p>.001), and BMD (p>.001) of the defects grafted with BCP compared with DBM grafted defects. HBO was effective in enhancing the bony healing of full thickness critical-sized as well as supracritical-sized defects in the rabbit calvarial model. However, there was a significant decline in the bone mineral content (BMC) of HBO treated grafted defects compared to NBO treated grafted defects (p<0.05). HBO enhanced bony healing in nongrafted rabbit calvarial critical-sized defects and may increase the rate of residual graft resorption in ABG and DBM grafted defects. 
Supervisor : Prof. George KB Sándor 
Thesis Type : Doctorate Thesis 
Publishing Year : 1433 AH
2012 AD 
Number Of Pages : 117 
Co-Supervisor : Prof. Riitta Suuronen 
Added Date : Thursday, August 9, 2012 

Researchers

Researcher Name (Arabic)Researcher Name (English)Researcher TypeDr GradeEmail
أحمد محمد سعيد جانJan, Ahmed Mohammed SaeedInvestigatorDoctorateamjan@kau.edu.sa

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 34084.pdf pdfAhmed Jan PhD Thesis 2012

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