• Journal of Periodontal and Implant Science
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• v.33 no.4
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• pp.673-691
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• 2003

The current interest in periodontal tissue regeneration has lead to research in bone graft, root surface treatments, guided-tissue regeneration, and the administration of growth factors as possible means of regenerating lost periodontal tissue. Several studies have shown that a strong correlation between platelet-rich plasma and the stimulation of remodeling and remineralization of grafted bone exists, resulting in a possible increase of 15-30% in the density of bone trabeculae. The purpose of this study was to study the histopathological correlation between the use of platelet-rich plasma and a bone xenograft used in conjunction with a non-resorbable guided-tissue membrane, e-PTFE, compared to a control group with regards to bone regeneration at the implant fixture site. Implant fixtures were inserted and graft materials placed into the left femur of in the experimental group, while the control group received only implant fixtures. In the first experimental group, platelet-rich plasma and BBP xenograft were placed at the implant fixture site, and the second experimental group had platelet-rich plasma, BBP xenograft, and the e-PTFE membrane placed at the fixture site. The degree of bone regeneration adjacent to the implant fixture was observed and compared histopathologically at 2 , 4, and 8 weeks after implant fixture insertion. The results of the experiment are as follows: 1. The rate of osseointegration to the fixture threads was found to be greater in the first experimental group compared to the control group. 2. The histopathological findings of the second experimental group showed rapid resorption of BBP with subsequent new bone formation replacing the resorbed BBP. 3. The second experimental group showed new bone formation in the area adjacent to the fixture threads beginning two weeks after fixture implantation, with continued bone remodeling in the areas mesial and distal to the fixture. 4. Significant new bone formation and bone remodeling was observed in both experimental groups near the implant fixture sites. 5. The rate of osseointegration at the fixture threads was greater in the second experimental group compared to the first group, and the formation of new bone and trabeculae around the fixture site occurred after the fourth week in the second experimental group. The results of the experiment suggest that a greater degree of new bone formation and osseointegration can occur at the implant fixture site by utilizing platelet-rich plasma and bone xenografts, and that these effects can be accelerated and enhanced by concurrent use of a non-resorbable guided tissue membrane.

• Journal of Marine Bioscience and Biotechnology
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• v.7 no.2
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• pp.58-70
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• 2015

Injectable RGD-bioconjugated Mussel Adhesive Proteins (RGD-MAPs) composite hydroxypropyl methylcellulose (HPMC) hydrogels provide local periodontal tissue for bone filling in periodontal surgery. Previously we developed a novel type of injectable self-supported hydrogel (2 mg/ml of RGD-MAPs/HPMC) based porcine nano hydroxyapatite (MPH) for dental graft, which could good handling property, biodegradation or biocompatibility with the hydrogel disassembly and provided efficient cell adhesion activity and no inflammatory responses. Herein, the aim of this work was to evaluate bone formation following implantation of MPH and collagen membrane in rabbit calvarial defects. Eight male New Zealand rabbits were used and four circular calvarial defects were created on each animal. Defects were filled with different graft materials: 1) collagen membrane, 2) collagen membrane with MPH, 3) collagen membrane with bovine bone hydroxyapatite (BBH), and 4) control. The animals were sacrificed after 2 and 8 weeks of healing periods for histologic analysis. Both sites receiving MPH and BBH showed statistically increased augmented volume and new bone formation (p < 0.05). However, there was no statistical difference in new bone formation between the MPH, BBH and collagen membrane group at all healing periods. Within the limits of this study, collagen membrane with MPH was an effective material for bone formation and space maintaining in rabbit calvarial defects.

• Korean Journal of Materials Research
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• v.17 no.6
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• pp.318-322
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• 2007

Porous ${\beta}-tricalcium$ phosphate $({\beta}-TCP)$ bioceramic was fabricated by pressureless sintering using commercial HAp and different volume percentages of PMMA powders (30-60 vol.%). The range of spherical pore size was about $200-250\;{\mu}m$ in diameter. By increasing the PMMA content, the number of pores and their morphology were dramatically changed as well as decreased the material properties. In case of using 60 vol.% PMMA content, network-type pores were found, due to the necking of the PMMA powders. The values of relative density, elastic modulus, bending strength and hardness of the 60 vol.% PMMA content sample, sintered at $1500^{\circ}C$, were about 46%, 22.2 GPa, 5MPa and 182 Hv respectively. Human osteoblast-like MG-63 cells and osteoclast-like Raw 264.7 cells were well grown and fully covered all of the porous ${\beta}-TCP$ bodies sintered at $1500^{\circ}C$.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.05
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• pp.130-132
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• 1996

It is well known when porous calcium phosphate ceramics are used as a bone graft substitute, new tissues or blood vessels are grown into the porous implant due to their excellent biocompatibility. In this study, the ${\beta}$-crystalline form of calcium metaphosphate, $Ca(PO_{3})_{2}$ is prepared by the controlled thermolysis of monocalcium phosphate, $Ca(H_{2}PO_{4})_{2}$. The diameter of cylindrical pores formed during cooling was controlled by a holding time at the melting point of a monocalcium phosphate and by the change of a recrystallization temperature, to obtained the most appropriate size (about $200{\mu}m$) of pores. It was observed that the increasing holding time at the melting point of monocalcium phosphate results in the decreases of pore sizes.

• Journal of Periodontal and Implant Science
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• v.35 no.2
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• pp.383-399
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• 2005

The successful implantation necessitate tissue regeneration m site of future implant placement, there being severe bone defect. Therapeutic approaches to tissue regeneration in the site have used bone grafts, root surface treatments, barrier membranes, and growth factors, the same way being applied to periodontal tissue regeneration. Great interest in periodontal tissue regeneration has lead to research in bone graft, guided-tissue regeneration, and the administration of growth factors as possible means of regenerating lost periodontal tissue. The blood component separated by centrifuging the blood is the platelet-rich plasma. There are growth factors, PDGF, $TGF{beta}1$, $TGF{beta}2$ and IGF in the platelet-rich plasma. The purpose of this study was to study the histopathological correlation between the use of platelet-rich plasma and the healing of bone defect around implant fixture site. Implant fixtures were inserted and graft materials were placed into the left femur of in the experimental group, while the control group received only implant fixtures. In the first experimental group, platelet-rich plasma and BBP xenograft were placed at the implant fixture site, and the second experimental group had platelet-rich plasma, BBP xenograft, and the e-PTFE membrane placed at the fixture site. The degree of bone regeneration adjacent to the implant fixture was observed and compared histopathologically at 2, 4, and 8 weeks after implant fixture insertion. The results of the experiment were as follows: 1. Bone remodeling in acid etched surface near the implant fixture of all experimental groups was found to be greater than new bone formation. 2. Bone remodeling in acid etched surface distant to the implant fixture of all experimental groups was decreased and new bone formation was not changed. 3. Significant new bone formation in machined surface near the implant fixture of bothl experimental groups was observed in 2 weeks. 4. New bone formation in machined surface distant to the implant fixture of both experimental groups was observed. Bone remodeling was significant in near the implant fixture and not in distant to the implant fixture. The results of the experiment suggested that the change of bone formation around implant. Remodeling in machined surface distant to the implant fixture of both experimental groups, and new bone formation and remodeling near the implant fixture were significant.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.5
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• pp.366-374
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• 2010

Introduction: This study evaluated the capability of silk fibroin (SF) and recombinant human bone morphogenetic protein-2 loaded SF (SF-BMP) as a bone defect replacement matrix when grafted in a calvarial bone defect of rats in vivo. Materials and Methods: A total 70 calvarial critical size defects (5.0 mm in diameter) made on 35 adult female Sprague-Dawley rats were used in this study. The defects were transplanted with (1) rhBMP-2 loaded silk fibroin graft (SF-BMP: 0.8+$10\;{\mu}g$), (2) Silk fibroin (SF: $10\;{\mu}g$), and (3) no graft material (Raw). The samples were evaluated with soft x-rays, alkaline phosphatase activity, calcium/phosphate quantification, histological and histomorphometric analysis at postoperative 4 and 8 weeks. Results: The SF-BMP group ($48.86{\pm}14.92%$) had a significantly higher mean percentage bone area than the SF group ($24.96{\pm}11.01%$) at postoperative 4 weeks.(P<0.05) In addition, the SF-BMP group ($40.01{\pm}12.43%$) had a higher % bone area at postoperative 8 weeks than the SF group ($33.26{\pm}5.15%$). The mean ratio of gray scale levels to the host bone showed that the SF-BMP group ($0.67{\pm}0.08$) had a higher mean ratio level than the SF group ($0.61{\pm}0.09$) at postoperative 8 weeks. These differences were not statistically significant.(P=0.168 and P=0.243, respectively) The ratio of the calcium and phosphate contents of the SF-BMP ($0.93{\pm}0.22$) group was lower than that of the SF ($1.90{\pm}1.42$) group at postoperative 4 weeks. However, the SF-BMP group ($0.75{\pm}0.31$) had a higher Ca/$PO_4$ ratio than the SF ($0.68{\pm}0.04$) at postoperative 8 weeks. These differences were not statistically significant.(P=0.126 and P=0.627, respectively) For the bone-specific alkaline phosphatase (ALP) activity, which is recognized as a reliable indicator of the osteoblast function, the SF-BMP ($23.71{\pm}8.60\;U/L$) groups had a significantly higher value than the SF group ($12.65{\pm}6.47\;U/L$) at postoperative 4 weeks.(P<0.05) At postoperative 8 weeks, the SF-BMP ($21.65{\pm}10.02\;U/L$) group had a lower bone-specific ALP activity than the SF group ($16.72{\pm}7.35\;U/L$). This difference was not statistically significant.(P=0.263) For the histological evaluation, the SF-BMP group revealed less inflammation, lower foreign body reactions and higher bone healing than the SF group at postoperative 4 and 8 weeks. The SF group revealed more foreign body reactions at postoperative 4 weeks. However, this immunogenic reaction decreased and the remnant of grafted material was observed at postoperative 8 weeks. For histomorphometric analysis, the SF-BMP group had a significantly longer bone length to total length ratio than those of the SF group at postoperative 4 and 8 weeks.(P<0.05) Conclusion: The rhBMP-2 loaded silk fibroin graft revealed fewer immunoreactions and inflammation as well as more new bone formation than the pure silk fibroin graft. Therefore, silk fibroin may be a candidate scaffold for tissue engineered bone regeneration.

• Journal of Periodontal and Implant Science
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• v.31 no.2
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• pp.437-449
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• 2001

The socket preservation procedure was a simple and effective technique, and has better prognosis for implantation. The socket preservation usually used barrier membrane in combination with/without alloplastic bone materials. A recently study had shown that a regenerative therapy to tooth extraction utilizing growth factors made better results. Platelet-rich plasma was clinically easy method that acquired the growth factors, and is known that accelerated new bone formation and mineralization of bone graft materials. The purpose of this study was to evaluate clinical and histopathologic results which occur following socket preservations using platelet-rich plasma and bovine bone powder. Twelve patients who required extraction of one or more teeth for implantation at the department of periodontics in Dankook University Dental Hospital were selected. Extraction sockets were treated by using platelet-rich plasma and bovine bone powder. 3 months later, we observed clinical and histopathological results as follows: 1. Internal vertical measurement was an average of 7.33mm preoperatively and statistically significantly decreased to an average of 1.42mm postoperatively(p<0.05). 2. External vertical measurement was an average of 3.33mm preoperatively and decreased to an average of 2.75mm postoperatively; therefore there was no significant difference. 3. Horizontal measurement was an average of 7.75mm preoperatively and statistically decreased to an average of 6.08mm postoperatively(p<0.05). 4. Osteocyte-like cells and new bone formation connected with bovine bone grafts were observed in histopathologic examination. This study implied that platelet-rich plasma and bovine bone powder grafts were effective treatment for socket preservation and regeneration of severe bony defect made by implantation failure.

• Journal of Periodontal and Implant Science
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• v.35 no.1
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• pp.235-250
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• 2005

The current interest in periodontal tissue regeneration has lead to research in bone graft, root surface treatments, guided-tissue regeneration, administration of growth factors, and the use of enamel matrix protein as possible means of regenerating lost periodontal tissue. Several studies have shown that a strong correlation between platelet-rich plasma and the stimulation of remodeling and remineralization of grafted bone exits, resulting in a possible increase of 15-30% in the density of bone trabeculae. The purpose of this study was to study the histopathological results and differences between the use of platelet-rich plasma and the use of enamel matrix $protein(Emdogain^?)$ about bone regeneration at the implant. Implant fixtures were inserted and graft materials placed into the left femur in the experimental group, while the only implant fixtures placed in the control group. In the first experimental group, platelet-rich plasma and xenograft were placed at the supracrestally placed implant site, and in the second experimental group, $Emdogain^{(R)}$ and xenograft placed at the supracrestally placed fixture site. The degree of bone regeneration adjacent to the implant fixture was observed and compared histopathologically at 2, 4, and 8 weeks after implant fixture insertion. The results of the experiment are as follows: 1. The rate of osseointegration to the fixture threads was found to be greater in the experimental group compared to in the control group. 2. The histopathological findings showed that the bone regeneration, the partial osseointegration existed at 4 weeks, and that osseointegration and bone density increaced in the experimental groups at 8 weeks. 3. The results showed that new bone formation and bone remodeling increased in the area near to the fixture in the first and second experimental groups at 8 weeks than at 4 weeks. The results showed that in the area distant from the fixture, new bone formation did not increase and bone remodeling decreased in the first experimental group at 4, 8 weeks, and that new bone formation increased in the second experimental group. 4. The histopathological findings showed that AZ deposition in the first experimental group was remarkable at 2, 8 weeks, and in the second experimental group at 2, 4, 8 weeks in the area distant from the fixture threads.

• Journal of Periodontal and Implant Science
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• v.35 no.2
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• pp.335-343
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• 2005

Inorganic bovine bone mineral has been widely researched as bone substitution materials in orthopedic and oral and maxillofacial application. OCS-B(NIBEC, Korea) is newly-developed inorganic bovine bone mineral. The aim of this study is to evaluate the safety and efficacy of bovine bone-derived bone graft material(OCS-B). Micro-structure of newly-developed inorganic bovine bone mineral(OCS-B) was analyzed by scanning electron microscope(SEM). Round cranial defects with eight mm diameter were made and filled with OCS-B in rabbits. OCS-B was inserted into femoral quadrant muscle in mouse. In scanning electron microscope, OCS-B was equal to natural hydroxyapatite. Rabbits were sacrificed at 2 weeks and 4 weeks after surgery and mice were sacrificed at 1 week and 2 weeks after surgery. Decalcified specimens were prepared and observed by microscope. In calvarial defects, osteoid and new bone were formed in the neighborhood of OCS-B at 2 weeks after surgery. And at 4 weeks after surgery osteoid and new bone bridge formed flourishingly. No inflammatory cells were seen on the surface of OCS-B at 1 week and 2 weeks in mouse experimental group. It is concluded that newly-developed inorganic bovine bone mineral(OCS-B) is a flourishing bone-forming material and biocompatible material.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.40 no.1
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• pp.17-20
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• 2014

Objectives: The aim of this study was to retrospectively evaluate the clinical survival rate of Astra Tech implants in the maxillary molar region performed with sinus lift and bone graft. Materials and Methods: Ninety-nine Astra Tech implants (Osseospeed) placed in the maxillary molar region using sinus lift from September 2009 to February 2012 were selected with a minimum follow-up period of 1 year. The height of alveolar bone, sinus approach technique, bone material and implant survival rate were evaluated. Results: Of the 99 implants, the survival rate was 90.9%; 8 implants failed within 1 year after implant placement, and 1 implant failed 1 year after implant loading. All failed implants were placed with sinus lift simultaneously. The average height of alveolar bone before implant placement was 6.9 mm, while the height of alveolar bone of failed implants was 2.1 mm, on average. Conclusion: Astra Tech implants placed in the maxillary molar region had generally good survival rates, but the relationship between reduced pre-implant alveolar bone height and implant failure requires further attention.