• Maxillofacial Plastic and Reconstructive Surgery
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• v.38
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• pp.16.1-16.9
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• 2016

Background: The association of biomaterial combined with repair factor-like platelet-rich plasma (PRP) has prospective values. Bovine-derived xenograft has been identified as an osteoconductive and biocompatible grafting material that provides osseointegration ability. PRP has become a valuable adjunctive agent to promote healing in a lot of dental and oral surgery procedures. However, there are controversies with respect to the regenerative capacity of PRP and the real benefits of its use in bone grafts. The purpose of this study was to assess the influence of PRP combined with xenograft for the repair of peri-implant bone defects. Methods: Twelve rabbits were used in this study, and the experimental surgery with implant installation was performed simultaneously. Autologous PRP was prepared before the surgical procedure. An intrabony defect (7.0 mm in diameter and 3.0 mm deep) was created in the tibia of each rabbit; then, 24 titanium dental implants (3.0 mm in diameter and 8.5 mm long) were inserted into these osteotomy sites. Thus, a standardized gap (4.0 mm) was established between the surrounding bony walls and the implant surface. The gaps were treated with either xenograft alone (control group) or xenograft combined with PRP (experimental group). After healing for 1, 2, 3, 4, 5, and 6 weeks, the rabbits were sacrificed with an overdose of KCl solution. Two rabbits were killed at each time, and the samples including dental implants and surrounding bone were collected and processed for histological analysis. Results: More newly formed bone and a better bone healing process were observed in control group. The histomorphometric analysis revealed that the mean percentage of bone-to-implant contact in the control group was significantly higher than that of the experimental group (25.23 vs. 8.16 %; P < 0.05, independent-simple t test, analysis of variance [ANOVA]). Conclusions: The results indicate that in the addition of PRP to bovine-derived xenograft in the repair of bone defects around the implant, PRP may delay peri-implant bone healing.

• Korean Journal of Veterinary Research
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• v.50 no.3
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• pp.171-177
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• 2010

The purpose of this study was to evaluate the osteogenic capacity of water extract of danshen (Salvia miltiorrhiza Bunge). We have established in rat critical-sized calvarial defect model using the combination with collagen scaffold and danshen hydrophilic extract. All rats were extinguished at 8 weeks after bone graft surgery, and the bone regeneration ability of bone grafting sides was evaluated by plain radiography and micro-CT. These results revealed water extract of danshen had the potential to promote osteogenesis especially continuous oral administration with local treatment compared to one-shot local treatment. This compound may provide a new alternative agent for growth factors to promote bone healing and bone regeneration. In conclusion, these results suggest that danshen hydrophilic extract have the potential to promote osteogenesis in bone defects. Further studies about fusion technology with salvianolic acid B, peptides, growth factors, and scaffolds using of the combination of tissue engineering, cell engineering and mechanical engineering are needed.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.28 no.3
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• pp.205-215
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• 2002

The purpose of this study was to evaluate the tissue response in various bone grafting materials, especially xenogenous bone materials in vivo, compare of bone formation capacity of various bone grafting materials on rat skull defects and evaluate the effect of Hyaluronic acid on healing of human Demineralized Freezed Dried Bone allogenous graft (DFDBA) materials in rat calvarial defects. 30 Sprague-Dawly rats were divided into 4 groups. $7{\times}7mm$ size bony defect were artificially prepared in the calvaria (both parietal bone) of all 30 rats and follwed group grafting of autogenous bone graft on right side and allogenic DFDBA on left side bone graft (rat DFDB) in 15 control group, but in 15 experimental group, xenograft (human DFDB) on left side, hyaluronic acid treated with xenograft on right side. Sequential sacrifices was performed at 1, 2, 4, 6, 8 weeks of experiment. These specimens were stained with H&E and MT stain, and then histologic analysis under light microscope was carried out. There were inflammatory reaction in all graft material during early stage. Autogenous and Allogenous DFDBA graft group observed inflammatory reaction at 1 week. Xenograft group persistant inflammatory reaction until 4 weeks, but in HA treated xenograft group inflammatory reaction was decreased at 2 weeks. Osteoblastic activity in control group was begun at 2 week, xenograft group was delayed at 6 weeks, however HA treated xenograft group was begun at 4 weeks. At 2 week, mild osteoclastic activity were observed in all xenograft group not in concerned to HA, but there was no difference each group after 4 weeks. There are most activated angiogenesis around graft mateirals in xenograft group at 2 weeks, but in HA treated xenograft group, decreased angiogenesis was observed at same time. Bone formation and bone maturation of xenograft group, there was no difference in HA treatment, was less than control group. Fibrosis around xenograft materials were observed until 6 weeks, there was no difference between xenograft and HA treated groups.

• Journal of Periodontal and Implant Science
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• v.42 no.2
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• pp.50-58
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• 2012

Purpose: This study evaluated histologically the tissue responses to and the effects of a customized nano-hydroxyapatite (n-HA) block bone graft on periodontal regeneration in a one-wall periodontal-defect model. Methods: A customized block bone for filling in the standardized periodontal defect was fabricated from prefabricated n-HA powders and a polymeric sponge. Bilateral $4{\times}{\times}4{\times}5$ mm (buccolingual width${\times}$mesiodistal width${\times}$depth), one-wall, critical-size intrabony periodontal defects were surgically created at the mandibular second and fourth premolars of five Beagle dogs. In each dog, one defect was filled with block-type HA and the other served as a sham-surgery control. The animals were sacrificed following an 8-week healing interval for clinical and histological evaluations. Results: Although the sites that received an n-HA block showed minimal bone formation, the n-HA block was maintained within the defect with its original hexahedral shape. In addition, only a limited inflammatory reaction was observed at sites that received an n-HA block, which might have been due to the high stability of the customized block bone. Conclusions: In the limitation of this study, customized n-HA block could provide a space for periodontal tissue engineering, with minimal inflammation.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.5
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• pp.431-437
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• 2005

Fibrin glue is composed of fibrinogen and thrombin and used in various regions for multiple use. Basic principle is that thrombin converts fibrinogen to fibrin in the presence of $Ca^{2+}$. The structure of fibrin is loose at the beginning, but after about 5 minutes a tight structure is formed under the influence of factor VIII which changes fibrin monomer into fibrin polymer. Fibrin glue is used for tissue adhesive, suture, local hemostasis, wound healing, closure of subdural space. Fibrin adhesive has been used in oral and maxillofacial surgery for hemostasis after tooth extraction in patients with coagulation disorders, skin graft fixation, reattachment of periodontal flaps, in combination with autogenous bone chips to fill the bony cavities following cyst removal, and for securing the hydroxyapatite granules for maxillary alveolar ridge augmentation. This study was designed for researching influence of fibrin glue during healing phase after making artificial bone defect.

• Journal of Periodontal and Implant Science
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• v.38 no.4
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• pp.603-610
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• 2008

Purpose: The guided bone regeneration (GBR) technique is widely used in periradicular surgery. However, there is still some controversy regarding the effectiveness of GBR in promoting bone healing after periradicular surgery. The purpose of this study was to evaluate the resorbable membrane on the osteointegration of immediate implants in sites with periradicular lesion that had been removed by periradicular surgery. Materials and methods: Six roots of lower second premolars and 15 roots of lower third and fourth premolars of dogs were used as control and experimental teeth, respectively. Periradicular lesions were induced only in the experimental teeth. Twelve weeks later, the control and experimental teeth were extracted and implants were placed immediately. Periradicular lesions were removed with osteotomy, curettage and saline irrigation. Resorbable membranes were used in experimental group 1 but not in experimental group 2. After 12 week of healing period, the implants were clinically not mobile and showed no signs of infection. Data obtained by histomorphometric analysis were analyzed by Kruskal-Wallis test. Results: The control group showed a significantly higher bone to implant contact (BIC) ($74.14{\pm}16.18$) than experimental group 1 ($40.28{\pm}15.96$) and 2 ($48.70{\pm}17.75$)(p<0.05). However, there was no significant difference between experimental group 1 and 2. Conclusion: Although BIC in experimental groups were lower than in control group, immediate implant can be successfully placed at extraction socket with periradicular lesion and osseous defect. However, the use of resorbable membrane in bony defect created during periradicular surgery was questioned.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.21 no.4
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• pp.325-331
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• 1999

We tested the bone regenerating capacity and histologic response of bioresorbable matrix-type implant, which was made with Poly(lactide-co-glycolide)(PLGA) and bone apatite for the carrier of bone morphogenetic protein(BMP). The critical size defect of 8mm in diameter was created at the calvaria of SD rats(n=18), and repaired with polymer implant with $15{\mu}g$ of rhBMP-2(n=9) or without it(n=9). At 2 weeks, 1 months after implantation, the animals were sacrificed(3 animals at every interval and group) and histologically evaluated. The calvarial defect which was repaired with polymer with BMP healed with newly formed bone about 70% of total defect. But that without BMP showed only 0 to under 30% bony healing. Inflammatory response was absent in both group through the experimental period, but there's marked foreign body giant response though it was a little less significant in polymer with BMP group. As the polymer was resorbed, the space was infiltrated and replaced by fibrovascular tissue, not by bone. In conclusion, our formulation of bioresorbable matrix implant loaded with bone morphogenetic protein works good as a bone regenerating material. However, it is mandatory to devise our system to have better osteoinductive and osteoconductive property, and less multinucleated giant cell response.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.38 no.5
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• pp.264-270
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• 2012

Many oral and maxillofacial bone defects are not self-healing. Guided bone regeneration (GBR), which uses a barrier membrane to prevent the soft tissues from invading the defect to enable slower-growing bone cells to penetrate the area, was developed as a therapy in the 1980s. Although there has been some success with GBR in some clinical situations, better treatments are needed. This review discusses the concept of GBR focusing on bioactive membranes that incorporate osteoconductive materials, growth factors and cells for improved oral and maxillofacial bone regeneration.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.6 s.249
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• pp.722-727
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• 2006

Bone fracture healing is one of the important topics in biomechanics, demanding computation simulations due to the difficulty of obtaining experimental or clinical results. In this study, we adopt the design space optimization method which was established by the authors as a tool for the simulation of bone growth using its evolutionary characteristics. As the mechanical stimulus, strain energy density is used. We assume that bone tissues over a threshold strain energy density will be differentiated and bone tissues below another threshold will be resorbed. Under compression and torsion as loadings, the filling process of the defect is well illustrated following the given mechanical criterion. It is shown that the design space optimization is an excellent tool for simulating the evolutionary process of bone growth, which has not been possible otherwise.

• Journal of Periodontal and Implant Science
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• v.31 no.1
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• pp.73-91
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• 2001

The present study was performed to compare effects of demineralized freeze-dried bone allograft(DFDBA) with deproteinized bovine bone mineral(DBBM) on periodontal fenestration defect in rats. Twelve adult male rats weighing 500 to 540 grams were used in this study. Periodontal fenestration defects were surgically created with tapered fissure bur(${\Phi}1mm$) at the left side of buccal surface of the mandible. The defect size was from anterior border of the first molar to anterior of the ascending ramus mesiodistally and from just below the alveolar crest to apically 1.5-2mm area apicocoronally with 2mm in depth. Rats were divided into control group, test group I and II. Four defects were assigned to the test group I grafted with DBBM and other 4 defects were assigned to the test group II grafted with DFDBA. The rest of defects were the negative control group. At 10 days and 35 days after surgery, 12 rats were sacrificed through intracardiac perfusion and specimens were obtained prepared with Hematoxylin-Eosin stain for light microscopic evaluation. The results of this study were as follows : 1. In the control group, new bone, osteoid, dense connective tissue were observed in the defects at 10 days. new bone formation was not found but loose connective tissue was formed in the defect and fibrous encapsulation of graft materials was shown in two test groups at 10 days. 2. In all groups, new bone formation was shown in the defect at 35 days. And in the control group, bone formation increased at 35 days than at 10 days. 3. In the test group I and II at 35 days, graft materials were combined with new bone and joined host bone. There was very close contact between new bone, graft materials, and host bone with no gaps. 4. In the test group I and II, new bone formation was similar to that in the control group but not exeeded. In conclusion, in the test group I new bone formation was similar to that in the test group II at 35 days, but there was infiltration of inflammatory cells at 10 days. DFDBA and DBBM were considered as the biocompatible graft materials and effective in the regeneration of new bone.