Characteristics and osteogenic effect of zirconia porous scaffold coated with beta-TCP/HA

PURPOSE: The purpose of this study was to evaluate the properties of a porous zirconia scaffold coated with bioactive materials and compare the in vitro cellular behavior of MC3T3-E1 preosteoblastic cells to titanium and zirconia disks and porous zirconia scaffolds. MATERIALS AND METHODS: Titanium and zirconia disks were prepared. A porous zirconia scaffold was fabricated with an open cell polyurethane disk foam template. The porous zirconia scaffolds were coated with beta-TCP, HA and a compound of beta-TCP and HA (BCP). The characteristics of the specimens were evaluated using scanning electron microscopy (SEM), energy dispersive x-ray spectrometer (EDX), and x-ray diffractometry (XRD). The dissolution tests were analyzed by an inductively coupled plasma spectrometer (ICP). The osteogenic effect of MC3T3-E1 cells was assessed via cell counting and reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: The EDX profiles showed the substrate of zirconia, which was surrounded by the Ca-P layer. In the dissolution test, dissolved Ca2+ ions were observed in the following decreasing order; beta-TCP > BCP > HA (P<.05). In the cellular experiments, the cell proliferation on titanium disks appeared significantly lower in comparison to the other groups after 5 days (P<.05). The zirconia scaffolds had greater values than the zirconia disks (P<.05). The mRNA level of osteocalcin was highest on the non-coated zirconia scaffolds after 7 days. CONCLUSION: Zirconia had greater osteoblast cell activity than titanium. The interconnecting pores of the zirconia scaffolds showed enhanced proliferation and cell differentiation. The activity of osteoblast was more affected by microstructure than by coating materials.

The Effect of PRF and PRP for New Bone Formation of beta-TCP in Skull of White Rabbit

Polyetheretherketone Cage filled with Beta-Tricalcium Phosphate versus Autogenous Tricortical Iliac Bone Graft in Anterior Cervical Discectomy and Fusion

OBJECTIVE: To compare clinical and radiologic results of two graft materials for anterior cervical discectomy and fusion (ACDF) with rigid plate fixation for cervical spinal disorder. METHODS: Twenty-eight patients treated with single-level ACDF with rigid plate fixation were retrospectively reviewed. They were divided into twogroups: Polyetheretherketone (PEEK) cage filled with beta-tricalcium phosphate (beta-TCP) in Group A (n=15); and autogenous tricortical iliac bone graft in group B (n=13). The average follow-up durations were 16.3 months and 19.90 months for group A and group B, respectively. Clinical outcomes were graded using the visual analogue scale (VAS) score and neck disability index (NDI). Interbody height, segmental kyphotic angle and overall kyphotic angle were used as parameters to evaluate radiographic change in the 2 treatment groups. RESULTS: Clinically, VAS scores and NDI significantly improved after the surgery in both groups (p0.05). The fusion rates after 12 months in group A and B were 93.3% and 100%, respectively. One case of cage subsidence which resulted in pseudoarthrosis occurred in group A. However, statistical analysis did not show difference in fusion rate between the two groups (p>0.05). CONCLUSION: ACDF using PEEK cage filled with alpha-TCP showed comparable clinical and radiologic results with the standard of autogenous iliac bone graft. However, pseudoarthrosis did occur even with rigid plate and screw fixation in ACDF using PEEK cage filled with beta-TCP. There is high likelihood of emerging pseudoarthrosis, especially when there is a sign of chronic and progressive cage subsidence.

Randomized clinical trial on the efficacy of Escherichia coli-derived rhBMP-2 with beta-TCP/HA in extraction socket

PURPOSE: This randomized clinical trial was conducted to assess the safety and effectiveness of the ErhBMP-2 in alveolar bone regeneration as well as preservation of the beta-TCP bone graft material that contains ErhBMP-2. MATERIALS AND METHODS: This study involved 72 patients at the 3 study centers. The patients, who were divided into 2 groups: the experiment group who had ErhBMP-2 coated TCP/HA and the control group who had TCP/HA graft material alone transplanted immediately after tooth extraction. CT was taken before and 3 months after the transplantation and healing status was compared between the two groups. The efficacy endpoints that were used to measure the degree of bone induction included alveolar bone height and 3 measurements of bone width. The paired t test was used to determine the significance of the changes (P<.05). RESULTS: Changes in alveolar bone height were -1.087 +/- 1.413 mm in the control group and -.059 +/- 0.960 mm in the experimental group (P<.01). At 25% extraction socket length [ESL], the changes were 0.006 +/- 1.149 mm in the control group and 1.279 +/- 1.387 mm in the experimental group. At 50% ESL, the changes were 0.542 +/- 1.157 mm and 1.239 +/- 1.249 mm, respectively (P<.01 for 25% ESL, and P<.05 for 50% ESL). During the experiment, no adverse reactions to the graft material were observed. CONCLUSION: ErhBMP-2 coated beta-TCP/HA were found to be more effective in preserving alveolar bone than conventional beta-TCP/HA alloplastic bone graft materials.

Effects of different sizes of Hydroxyapatite/beta-Tricalcium phosphate particles on vertical bone augmentation / 대한치과보철학회지

PURPOSE: This study was aimed to evaluate the effect of different sizes of beta-TCP/HA particles on vertical bone augmentation using titanium mesh in the cranium of rabbits. MATERIAL AND METHODS: Six white rabbits weighing 5kg were used. Four circular grooves of 6mm diameter were made by trephine, and five small holes were drilled in the inner surface of each circular gooves. Different sizes of grafts (small 0.3 - 0.5 mm, medium 0.5 - 1.0, large 1.0 - 2.0 mm) were placed respectively in the experimental groups. Titanium mesh (height 3 mm, width 6 mm) was placed. After 8weeks healing period, the rabbits were euthanized, and the specimens were prepared for histological findings. New bone formation and remaining graft area were measured to calculate the ratio of areas occupying the inner space of titanium mesh. Mann-Whitney U-test and Wilcoxon signed rank-test were used for statistical analysis (alpha = .05). RESULTS: The experimental groups with beta-TCP/HA graft showed a significantly higher new bone formation (P = .003). Comparing different sizes of beta-TCP/HA, there was no statistical difference in terms of new bone formation. The vertical bone formation (i.e. new bone and graft area) was significantly greater in beta-TCP/HA groups (P = .001). In comparison between different sizes of beta-TCP/HA, medium size group had significantly greater area than large particle size group (P = .039). CONCLUSION: The use of beta-TCP/HA with titanium mesh showed a higher vertical bone formation, particularly the medium sized beta-TCP/HA particles (0.5 - 1.0 mm) produced better results in vertical bone augmentation.

Implantation of canine umbilical cord blood-derived mesenchymal stem cells mixed with beta-tricalcium phosphate enhances osteogenesis in bone defect model dogs

This study was performed to evaluate the osteogenic effect of allogenic canine umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs) mixed with beta-tricalcium phosphate (beta-TCP) in orthotopic implantation. Seven hundred milligrams of beta-TCP mixed with 1 x 10(6) UCB-MSCs diluted with 0.5 ml of saline (group CM) and mixed with the same volume of saline as control (group C) were implanted into a 1.5 cm diaphyseal defect and wrapped with PLGC membrane in the radius of Beagle dogs. Radiographs of the antebrachium were made after surgery. The implants were harvested 12 weeks after implantation and specimens were stained with H&E, toluidine blue and Villanueva-Goldner stains for histological examination and histomorphometric analysis of new bone formation. Additionally, UCB-MSCs were applied to a dog with non-union fracture. Radiographically, continuity between implant and host bone was evident at only one of six interfaces in group C by 12 weeks, but in three of six interfaces in group CM. Radiolucency was found only near the bone end in group C at 12 weeks after implantation, but in the entire graft in group CM. Histologically, bone formation was observed around beta-TCP in longitudinal sections of implant in both groups. Histomorphometric analysis revealed significantly increased new bone formation in group CM at 12 weeks after implantation (p < 0.05). When applied to the non-union fracture, fracture healing was identified by 6 weeks after injection of UCB-MSCs. The present study indicates that a mixture of UCB-MSCs and beta-TCP is a promising osteogenic material for repairing bone defects.

The effects of beta-TCP/rhBMP-2 on bone formation in osteoblast-like cells induced from bone marrow-derived mesenchymal stem cells

The present study aimed to investigate the osteogenic potentials of differentiated osteoblast-like cells (DOCs) induced from bone marrow-derived mesenchymal stem cells (MSCs) on beta-tricalcium phosphate (beta-TCP) with recombinant human bone morphogenetic protein (rhBMP-2) in vitro. Osteoblast differentiation was induced in confluent cultures by adding 100 nM dexamethasone, 10 mM beta-glycerophosphate, 50 mM L-ascorbic acid. The Alizarin red S staining and reverse transcriptase-polymerase chain reaction (RT-PCR) were perfomed to examine the mRNA expression of alkaline phosphatase (ALP), bone sialoprotein (BSP), osteocalcin (OCN), receptor activator for nuclear factor kappaB ligand (RANKL), runt-related transcription factor 2 (RUNX2), collagen-I (COL-I). There were no significant differences in the osteogenic potentials of DOCs induced from MSCs on beta-TCP(+/-). According to the incubation period, there were significant increasing of Alizadin red S staining in the induction 3 weeks. The mRNA expression of ALP, RUNX2, and RANKL were higher in DOCs/beta-TCP(-) than DOCs/beta-TCP(+). According to rhBMP-2 concentrations, the mRNA expression of BSP was significantly increased in DOCs/beta-TCP(+) compared to that of DOCs/beta-TCP(-) on rhBMP 10 ng/ml. Our study presented the beta-TCP will have the possibility that calcium phosphate directly affect the osteoblastic differentiation of the bone marrowderived MSCs.

The effect of prp on the bone regeneration of beta-tcp grafted in rabbit cranial bone defect

The effect of pulsed electromagnetic fields on beta-TCP graft in rabbit cranial bone defect

The purpose of this research was to investigate whether pulsed electromagnetic field (PEMF) stimulation applied to the rabbit cranial defects grafted with beta-tricalcium phosphate (beta-TCP) could affect the new bone formation. With 16 New Zealand white rabbits under the same condition, bilateral calvarial bone defects were formed around the sagittal suture line. The defect on the left side was grafted with beta-TCP, while on the right side was grafted by harvested autogenous bone. PEMF was applied to 8 rabbits for 8 hours per day. The bony specimen were divided into 3 groups, the group 1 was autogenous bone grafted specimen, the group 2 was beta-TCP grafted with PEMF, and the group 3 was beta-TCP grafted without PEMF. We investigated the bone regeneration and growth factor expression at 2, 4, 6, and 8 weeks. As a result, BMP 2 was expressed in the group 1 from 2 weeks, the group 2 from 4 weeks, and the group 3 from 6 weeks. BMP 4 was expressed in the group 1 from 2 weeks, in the group 2 and the group 3 from 4 weeks. 4. There was no significant difference in expression pattern of BMP 7, PDGF, VEGF, and TGF-beta1 during grafted bone regeneration in group 1, 2, and 3. According to our results, PEMF stimulation could be effective on the new bome formation in animal study, and have a feasibility of clinical use.

Bone formation e ffe ct o f HA/beta-TCP composite powders in rabbit calvarial bone defects: Histologic study / 대한치주과학회지

The purpose of the present study was to evaluate the histologic results of bone cavities that were surgically created in the calvaria of rabbit and filled with HA/beta-TCP composite powders, which had been developed in Korea (Dentium, Korea). Ten young adult rabbits were used. Four defects were surgically produced in calvaria of each rabbit. Each rabbit was anesthetized with Ketamine-HCl (5 mg/kg, Yuhan Cor. Korea) and Xylazine-HCl (1.5 ml/kg, Yuhan Cor. Korea)). An incision was made to the bony cranium and the periosteum was reflected. Using a trephine bur (external diameter: 8 mm, 3i, USA), 4 'through-and-through' bone defects were created with copious irrigation, and classified into 4 groups: control group: no graft materials, experimental group I: normal saline + graft materials: experimental group II: venous blood + graft materials: experimental group III: graft materials only. The defects were randomly filled with graft materials. The defects were closed with resorbable suture material. At the end of the surgical procedure, all animals received a single intramuscular injection of antibiotics Gentamicin (0.1 mg/kg, Dae Sung Microb. Korea). Rabbits were sacrificed with phentobarbital (100 mg/kg) intravenously at 1-, 2-, 4-, 6- and 8-week after. Specimens were treated with hydrochloric acid decalcifying solution (Fisher Scientific, Tustin, CA) and sectioned by bisecting the 8 mm diameter defects. The histologic specimens were prepared in the general method with H & E staining at 6 micrometer in thickness. The results were as follows; 1. New bone formation showed from after 2-week of surgery in defect area. As time lapsed, lots of new bone formation and mature bones showed. 2. Histologically, degree of new bone formation could not be discerned among the experimental groups. But, for experimental group II, lots of cells gathered around graft materials after 1-week of surgery, new bone formed slightly faster and than the others at 1-week after. For experimental group I, a few inflammatory finding showed around graft material at after 1-week and after 2-week of surgery. 3. No bone formation did show for control group. Based on histologic results, the new HA/beta-TCP composite powders appeared to act as a scaffolding material for regeneration of osseous defects.

The experimental study of the bone regeneration on rabbit maxillary sinus grafting with beta-TCP

PURPOSE:Maxillay sinus grafting is an effective treatment procedure to improve bone height in the posterior maxillar area for implant installation. Beta-tricalciumphosphate(beta-TCP) was introduced to be grafting substitute material, providing a reasonable bio-degradation time, no need for harvesting procedure. The purpose of this study is to evaluate bone healing and regeneration phase using histomorphometric and immunohistochemical analysis. MATERIAL AND METHODS:Sixteen rabbits were divided into 4 groups. Bi-lateral maxillary sinus membranes were elevated at each rabbits, beta-TCP was augmented in left sinus, autogenous bone was augmented in right sinus. The rabbits were sacrificed at 2, 4, 8 and 12 weeks. We investigated the bone regeneration and growth factor expression. RESULTS: 1. The mean new bone volume formation was 28.99+/-6.55%, 49.54+/-5.47%, 69.09+/-8.90% in autogenous grafted area, and 22.86+/-5.56%, 24.00+/-4.09%, 34.11+/-3.37% in beta-TCP area at 4, 8, 12 weeks. Therefore, new bone formation in autogenous bone was significantly higher than beta-TCP (p<0.05). 2. The BMP 2/4 expression in autogenous bone grafted area was higher at 4, 8 weeks. 3. There was no difference in expression pattern of BMP-7/PDGF/VEGF during grafted bone regeneration. CONCLUSION:The authors we conclude that the autogenous bone graft was faster than beta-TCP in bone regeneration, and the BMP 2/4 were more important in graft bone regeneration.

The experimental study of the bone regeneration on rabbit maxillary sinus grafting with beta-TCP

PURPOSE:Maxillay sinus grafting is an effective treatment procedure to improve bone height in the posterior maxillar area for implant installation. Beta-tricalciumphosphate(beta-TCP) was introduced to be grafting substitute material, providing a reasonable bio-degradation time, no need for harvesting procedure. The purpose of this study is to evaluate bone healing and regeneration phase using histomorphometric and immunohistochemical analysis. MATERIAL AND METHODS:Sixteen rabbits were divided into 4 groups. Bi-lateral maxillary sinus membranes were elevated at each rabbits, beta-TCP was augmented in left sinus, autogenous bone was augmented in right sinus. The rabbits were sacrificed at 2, 4, 8 and 12 weeks. We investigated the bone regeneration and growth factor expression. RESULTS: 1. The mean new bone volume formation was 28.99+/-6.55%, 49.54+/-5.47%, 69.09+/-8.90% in autogenous grafted area, and 22.86+/-5.56%, 24.00+/-4.09%, 34.11+/-3.37% in beta-TCP area at 4, 8, 12 weeks. Therefore, new bone formation in autogenous bone was significantly higher than beta-TCP (p<0.05). 2. The BMP 2/4 expression in autogenous bone grafted area was higher at 4, 8 weeks. 3. There was no difference in expression pattern of BMP-7/PDGF/VEGF during grafted bone regeneration. CONCLUSION:The authors we conclude that the autogenous bone graft was faster than beta-TCP in bone regeneration, and the BMP 2/4 were more important in graft bone regeneration.

Sinus augmentation with beta-TCP

Sinus floor augmentation has been proven an effective treatment procedure to increase bone volume in the posterior edentulous maxilla. Autogenous bone considered to be the best material for reconstructive bone surgery and has been successfully used as a graft material to augment posterior maxilla. However, the collection of autogenous bone required extra risks for morbidity and complaints. So, various bone graft materials included beta-tricalcium phosphate(beta-TCP) has been introduced for replacing the autogenous bone. The objective of this clinical study was to determine the predictability of endosseous implant placed in a maxillary sinus with beta-TCP grafting. We performed sinus elevation with beta-TCP to install the implant in the 10 maxillary cases. The prosthetic procedure was performed 6-9 months after. The implant-prosthetics was checked about 1 year. We checked the implant and measured the maximum bite force to evaluate the function of the implant. There was not observed the specific problem and complication in dental implant and maxillary sinus in the grafted materials. The maximum bite force was 558N in case of natural tooth, 365N in implant without grafting, 318N in implant with beta-TCP grafting. There was no significant difference between with and without sinus grafting on maximum bite force(P>0.05). As though the long term check-up is needed, the grafting of beta-TCP as a osteoconductive materials can expand the volume and induce dense new bone formation in maxillary sinus. So, this short-term results support that beta-TCP can be a suitable material for sinus augmentation.

The experimental study of the bone regeneration on beta-TCP in rabbit cranial bone

Pure-phase beta-tricalcium phosphate(beta-TCP) proved to be a bone regeneration material, providing the patient with vital bone at the defect site in a reasonable time, making a second surgical procedure for bone harvesting unnecessary. This study compares bone healing and BMP 2/4 expression in cranial defects in rabbits grafted with autogenous bone and beta-TCP. Thirty New Zealand White rabbits was divided into 3 group of 10 animals each. Bilateral calvarial defects were made in the parietal bones of each animal. beta-TCP placed in one defect and the other defects was filled with autogenous bone. The animal were sacrificed at 4, 8 and 12 weeks. Immunohistochemical analysis was used to investigate the expression of BMP 2/4. 1. The new bone formation around autogenous bone from 4 weeks and beta-TCP from 8 weeks. 2. In autogenous bone graft, BMP 2/4 expression was decreased from 4 to 12 weeks. 3. In beta-TCP graft, BMP 4 expression was increased from 8 to 12 weeks. But, BMP 2 was observed from 12 weeks. This study showed that bone healing, regeneration and, BMP 2/4 expression are delayed in grafted beta-TCP than autogenous bone.