title: Guided bone regeneration in standardized calvarial defects using beta-tricalcium phosphate and collagen membrane: a real-time in vivo micro-computed tomographic experiment in rats.
abstract: Guided bone regeneration (GBR) procedures using graft materials have been used for reconstruction of osseous defects. The aim of the present in vivo micro-computed tomographic (µCT) and histologic study was to assess in real time the bone regeneration at GBR sites in standardized experimental calvarial defects (diameter 3.3 mm) using β-tricalcium phosphate (β-TCP) with and without collagen membrane (CM). A single full-thickness calvarial defect was created on the left parietal bone in young female Wistar albino rats (n = 30) weighing approximately 300 g and aged about 6 weeks. The animals were randomly divided into three groups for treatment, based on calvarial defect filling material: (1) control group (n = 10); (2) β-TCP + CM group (n = 10); (3) β-TCP group (n = 10). Real-time in vivo µCT analyses were performed immediately after surgery and at 2, 4, 6 and 10 weeks to determine the volume and mineral density of the newly formed bone (BVNFB, MDNFB) and remaining β-TCP particles (VRBP, MDRBP). The animals were killed at 10 weeks and calvarial specimens were evaluated histologically. In the control group, MDNFB increased significantly at 6 weeks (0.32 ± 0.002 g/mm(3), P < 0.01) compared to that at baseline. In β-TCP + CM group, BVNFB (1.10 ± 0.12 mm(3), P < 0.01) and MDNFB (0.13 ± 0.02 g/mm(3), P < 0.01) significantly increased at the 4th week than baseline. In the β-TCP group, BVNFB (1.13 ± 0.12 mm(3), P < 0.01) and MDNFB (0.14 ± 0.01 g/mm(3), P < 0.01) significantly increased at 6 weeks compared to that at baseline. Significant reduction in VRBP was neither seen in the β-TCP + CM group nor in the β-TCP group. While in the β-TCP + CM group MDRBP was reduced significantly at 6 weeks (0.44 ± 0.9 g/mm(3), P < 0.01) from baseline (0.98 ± 0.03 g/mm(3)), similar significant reduction in MDRBP from baseline (0.92 ± 0.07 g/mm(3)) was seen only at 10 weeks (0.45 ± 0.06 g/mm(3), P < 0.05) in the β-TCP group. Histologic findings at 10 weeks revealed greater amount of NFB with osteocytes in the matrix, in the β-TCP + CM group than in the β-TCP group. Biomechanical assessment of NFB for hardness (H) and elastic modulus (E) revealed significantly higher values for the β-TCP + CM group (H = 612.6 ± 4.28 Mpa; E = 13.57 ± 0.07 Gpa) when compared to those of the control (H = 192.1 ± 4.93 Mpa; E = 6.76 ± 0.04 Gpa) and the β-TCP groups (H = 241.9 ± 6.29 Mpa; E = 4.34 ± 0.06 Gpa). In conclusion, based on real-time assessment, NFB is formed in calvarial defects as early as 4 weeks following GBR with β-TCP + CM as compared to 6 weeks when β-TCP alone was used.
authors.affiliation: Department of Oral and Maxillofacial Surgery, College of Dentistry, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Sundar
authors.initials: S
authors.lastname: Ramalingam
authors.affiliation: Department of Periodontics and Community Dentistry, College of Dentistry, King Saud University, Riyadh, Saudi Arabia.|Engineer Abdullah Bugshan Research Chair for Growth Factors and Bone Regeneration, 3D Imaging and Biomechanical Laboratory, College of Dentistry, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Abdulaziz
authors.initials: A
authors.lastname: Al-Rasheed
authors.affiliation: Department of Substitutive Dental Sciences, College of Dentistry, University of Dammam, Dammam, Saudi Arabia.
authors.forename: Aws
authors.initials: A
authors.lastname: ArRejaie
authors.affiliation: Department of Oral and Maxillofacial Surgery, College of Dentistry, King Saud University, Riyadh, Saudi Arabia.|Engineer Abdullah Bugshan Research Chair for Growth Factors and Bone Regeneration, 3D Imaging and Biomechanical Laboratory, College of Dentistry, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Nasser
authors.initials: N
authors.lastname: Nooh
authors.affiliation: Department of Oral and Maxillofacial Surgery, College of Dentistry, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Al-Kindi
authors.affiliation: Department of Periodontics and Community Dentistry, College of Dentistry, King Saud University, Riyadh, Saudi Arabia. hezaimik16@gmail.com.|Engineer Abdullah Bugshan Research Chair for Growth Factors and Bone Regeneration, 3D Imaging and Biomechanical Laboratory, College of Dentistry, King Saud University, Riyadh, Saudi Arabia. hezaimik16@gmail.com.
authors.forename: Khalid
authors.initials: K
authors.lastname: Al-Hezaimi
mesh_terms: D000818:Animals; D001861:Bone Regeneration; D002130:Calcium Phosphates / Q000627:therapeutic use*; D003094:Collagen / Q000627:therapeutic use*; D005260:Female; D010012:Osteogenesis; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D012886:Skull / Q000473:pathology
chemical_list: D002130:Calcium Phosphates; D003094:Collagen; C018392:tricalcium phosphate
keywords: Collagen membranes; Critical-size defect; Guided bone regeneration; In vivo micro-computed tomography; Tricalcium phosphate