• Journal of Dental Rehabilitation and Applied Science
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• v.33 no.4
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• pp.291-298
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• 2017

It is challenging to produce esthetic implant restoration in the narrow anterior maxilla region where insufficient volume of alveolar bone could limit the angle and position of implant fixture, if preceding bone augmentation is not considered. Ideal angle and position of implant fixture placement should be established to reproduce harmonious emergence profile with marginal gingiva of implant prosthesis, bone augmentation considered to be preceded before implant placement occasionally. In this case, preceding bone augmentation has been operated before esthetic implant prosthesis in narrow anterior maxilla region. Preceded excessive bone augmentation in buccal area allowed proper angulation of implantation, which compensates unfavorable implant position. Provisional restorations were corrected during sufficient period to make harmonious level of marginal gingiva and interdental papilla. The definite restoration was fabricated using zirconia core based glass ceramic. Functionally and esthetically satisfactory results were obtained.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.2
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• pp.112-119
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• 2011

Purpose: Collagen membranes are used extensively as bioabsorbable barriers in guided bone regeneration. However, collagen has different effects on tissue restoration depending on the type, structure, degree of cross-linking and chemical treatment. The purpose of this study was to evaluate the inflammatory reaction, bone formation, and degradation of dehydrothermal treated porcine type I atelocollagen (CollaGuide$^{(R)}$) compared to of the non-crosslinked porcine type I, III collagen (BioGide$^{(R)}$) and the glutaldehyde cross-linked bovine type I collagen (BioMend$^{(R)}$) in surgically created bone defects in rat mandible. Methods: Bone defect model was based upon 3 mm sized full-thickness transcortical bone defects in the mandibular ramus of Sprague-Dawley rats. The defects were covered bucolingually with CollaGuide$^{(R)}$, BioMend$^{(R)}$, or BioGide$^{(R)}$ (n=12). For control, the defects were not covered by any membrane. Lymphocyte, multinucleated giant cell infiltration, bone formation over the defect area and membrane absorption were evaluated at 4 weeks postimplantation. For comparison of the membrane effect over the bone augmentation, rats received a bone graft plus different covering of membrane. A $3{\times}4$ mm sized block graft was harvested from the mandibular angle and was laid and stabilized with a microscrew on the naturally existing curvature of mandibular inferior border. After 10 weeks postimplantation, same histologic analysis were done. Results: In the defect model at 4 weeks post-implantation, the amount of new bone formed in defects was similar for all types of membrane. Bio-Gide$^{(R)}$ membranes induced significantly greater inflammatory response and membrane resorption than other two membranes; characterized by lymphocytes and multinucleated giant cells. At 10 weeks postoperatively, all membranes were completely resorbed. Conclusion: Dehydrotheramal treated cross-linked collagen was safe and effective in guiding bone regeneration in alveolar ridge defects and bone augmentation in rats, similar to BioGide$^{(R)}$ and BioMend$^{(R)}$, thus, could be clinically useful.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.6
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• pp.455-464
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• 2004

The purpose of this study was to evaluate and compare the influence of Steroid topical irrigation and implant surface on bone healing in the irradiated rabbit tibia. Implant to bone contact surface ratio and the pattern of bone healing around hydroxyapatite(HA) coated implant and pure titanium (Ti) implant which were inserted into the irradiated rabbit tibia were compared. 16 Korean house mature male rabbits were used as experimental animal. Each rabbit received 15 Gy of irradiation. 4 weeks after the irradiation, two holes were prepared in the irradiated tibia of each rabbits, where two surface type of implants were inserted :1) HA coated type and 2) pure Ti type. Right before placing implants, one group of rabbit received steroid irrigation and the other group did saline. After the irrigation, two implants of HA coated type and pure Ti type were inserted into the tibia of each rabbits. Each rabbit were sacrificed at 2nd, 4th, and 8th week after the implantation and the specimens were observed by the light microscope. The pattern of bone healing and histomorphometric analysis of the implant-bone interface were done. The results were as follows. 1. All implants inserted into the irradiated tibia of rabbit did not show any sign of clinical mobility and the bone around implants inserted into the irradiated tibia of rabbit did not show any resorption. 2. The bone to implant contact surface ratio around HA coated implants that received steroid irrigation got more bone to implant contact surface ratio than that of the saline irrigation. This result showed statistically significant(p<0.05). There was no statistically significant difference in 8th week group. 3. Though there was no statistically significant difference HA coated implants had more bone to implant contact surface ratio than pure Ti implant in 2nd and 4th groups, and there was no difference in 8th week group. 4. All implants inserted into the irradiated tibia of rabbit had exhibited successful osseointegraion.

• The Journal of Korean Academy of Prosthodontics
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• v.35 no.1
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• pp.43-66
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• 1997

Dental implant may be immediately placed in postextraction socket which has alveolar bone defect. The purpose of this study was to compare the bone regeneration and bone quality around defects adjacent to implants that were placed into extraction sockets according to EFEB, GTAM barrier and GTAM barrier with DFDB. Mandibular P2, P3 and P4 were extracted bilaterally in dogs, and buccal defects were created about 4mm in depth and 3.3mm in width. Screwed pure titanium implants, 3.8mm in diameter and 10mm in length, were placed into the extraction sockets. The experimental groups were divided into four groups : the G group was covered with a GTAM barrier on the defective area, the D+G group was filled with DFEB and covered with a GTAM barrier, the D group was filled with DFDB only and the control group was sutured without any special treatment on the defective area. The experimental animals were killed after 12 weeks and specimens were prepared for light microscopic evaluation and fluorescent dyes were administered daily for 2 weeks after implantation, and injected on the 4th and 11th week for fluorescent microscopic examination to observe new bone formation and bone remodeling. The new Bone height of the buccal defect was measured and compared with the another for bone gain and the removal torque for the implant was measured for the comparison of bone density and bone-implant osseointegration. Results obtained were as follows : 1. Experimental groups showed bone regeneration in oder from D+G, G, D group and control. D+G and G group was significantly from D group and control(P<0.01). 2. In the defective area of control the regenerated alveolar bone showed poorly developed lamellated structure and fibrous tissue intervention into the bone-implant interface but the others showed well developed lamellated structure and osseointegration. 3. All implant groups showed no significaant difference in the removal torque for implant(P>0.05) These results suggest that immediate implants placed in defective sockets were successfully osseointegrated and utilizing placed in defective sockets were successfully osseointegrated and utilizing not only the combination of GTAM and DFDB but also only the GTAM was favorable for the predictable regeneration of the defective area.

• Journal of Periodontal and Implant Science
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• v.39 no.sup2
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• pp.213-222
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• 2009

Purpose: Recently, interest in chitosan has increased due to its excellent biological properties such as biocompatibility, antibacterial effect, and rapid healing capacity. On the other hand, hydroxyapatite is used as a bone substitute in the fields of orthopedics and dentistry. The hydroxyapatite-chitosan (HA-CS) complex containing hydroxyapatite nanoparticles was developed for synergy of both biomaterials. The objective of this study was to evaluate the effect of hydroxyapatite (HA)-chitosan (CS) membrane on bone regeneration in the rat calvarial defect. Methods: Eight-millimeter critical-sized calvarial defects were created in 70 male Sprague-Dawley rats. The animals were divided into 7 groups of 10 animals and received either 1) chitosan (CS) 100% membrane, 2) hydroxyapatite (HA) 30%/CS 70% membrane, 3) HA 30%/CS 70%, pressed membrane, 4) HA 40%/CS 60% membrane, 5) HA 50%/CS 50% membrane, 6) HA 50%/CS 50%, pressed membrane, or 7) a sham . surgery control. The amount of newly formed bone from the surface of the rat calvarial defects was measured using histomorphometry, following 2- or 8- week healing intervals. Results: Surgical implantation of the HA - CS membrane resulted in enhanced local bone formation at both 2 and 8 weeks compared to the control group. The HA - CS membrane would be significantly more effective than the chitosan membrane in early bone formation. Conclusions: Concerning the advantages of biomaterials, the HA-CS membrane would be an effective biomaterial for regeneration of periodontal bone. Further studies will be required to improve the mechanical properties to develop a more rigid scaffold for the HA-CS membrane.

• Journal of Dental Rehabilitation and Applied Science
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• v.25 no.3
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• pp.279-285
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• 2009

The purpose of this study was to evaluate histologic result of bone substituting materials on extraction sockets. We compare the histologic findings of control, $MBCP^{(R)}$, $Polybone^{(R)}$. Mandibular premolar teeth of Beagle dogs were extracted available for bone filling. All alveolar extraction sockets were thoroughly debrided with surgical curet to remove the periodontal ligament. The graft materials were filled into the extraction sockets. The animals were sacrified 90 days after implantation. Both treated and control mandibular sites were histologically evaluated with light microscopy. Histological observation at 90 days revealed that control and experimental sites were healed uneventfully without any adverse tissue reaction. Regenerated new bone formation ratio is 34.5% for control, 28.4% for $MBCP^{(R)}$, 23.8% for $Polybone^{(R)}$. From this results, it was suggested that $MBCP^{(R)}$, $Polybone^{(R)}$ are promising bone substituting materials to promote normal tissue healing and new bone formation.

• The Journal of Korean Academy of Prosthodontics
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• v.52 no.2
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• pp.128-135
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• 2014

Treatment options for partially edentulous patients are fixed partial denture, removable partial denture and implant supported fixed partial denture. In case of a patient with a few remaining teeth, removable partial denture and implant supported fixed prosthesis are available. For implant fixed prothesis, enough implant fixtures are required and the patient's general condition, local factors and economic status must be considered. When the condition of the abutments and the residual ridge is favorable and the prosthesis is well designed, removable partial denture can be an option. In removable partial denture, the bilateral support is important. If the teeth remain unilateral, harmful stress is put on the abutments by the fulcrum line. In this situation, strategic implantation and implant-retained or assisted removable partial denture is beneficial to the retention and support of the denture. And this can be cost-effective, functional and esthetic choice of treatment. This article describes the prosthodontic rehabilitation of Maxillary Kennedy class I partially edentulous patients. In these two cases, the patients had a small number of teeth and they were restored by the combination of a removable partial denture and dental implants.

• 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.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.2
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• pp.131-138
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• 2007

The purpose of this study was to observe the effect of calcium and vitamin D to the titanium implant osseointegration in animal model. 32 rats, 10 weeks of age, were divided into two group: additional calcium and vitamin D supplementation group and a control group. Titanium screw implant(diameter, 2.0mm; length, 3.5mm; pitch-height 0.4mm) were placed into tibia of 32 rats, 16 in the control group and 16 in the experimental group. The rats were sacrificed at different time interval(1, 2, 4, and 8 weeks after implantation) for histopathologic observation, histomorphometric analysis and immunohistochemistry with osteocalcin and osteopontin antibody. Histopathologically findings, newly formed bone was seen at 1 weeks and became lamellar bone at 2 weeks, and mature trabecullar bone was seen at 4 weeks experimental group. In control group, thickness of regenerated bone increased till 4 weeks gradually and trabecullar bone was seen at 8 weeks. By histomorphometric analysis, bone marrow density was increased significantly at 1 and 2 weeks in experimental group compared to control group. Osteocalcin immunoreactivity was strong at 1 week experimental group and reduced after 4 weeks gradually. But it was continuously weakly from 1 to 4 weeks in control group. Osteopontin immunoreactivity was very strong in newly formed bone from 2 to 8 weeks experimental group. And the amount of osteopontin expression was more abundant in experimental group. The results of this study suggest that calcium and vitamin D supplementation promotes bone healing around dental implants

• Maxillofacial Plastic and Reconstructive Surgery
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• v.22 no.3
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• pp.274-287
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• 2000

The use of dental implants has increased tremendously in recent years and is expected to increase even more in the future. The successful outcome of any implant procedure is surely dependent on interrelationship of the various components of an equation that includes biocompatibility of implant material, macroscopic and microscopic nature of the implant surface, the status of implant bed, surgical technique, undisturbed healing phase and subsequent prosthetic design and long-term loading phase. The purpose of this study was to clarify the effects of adrenalectomy on the osseointegration of pure titanium implants. Seventy rats, 11 weeks of age, were divided into two groups : an adrenalectomized group and a control group. Titanium screw implant(diameter, 2.0mm; length, 3.5mm) was placed into left tibia of 70 rats, 35 in control group and 35 in the experimental group. The rats were sacrificed at different time interval (1, 2, 3, 4, 6, 8, and 12 weeks after implantation) for histopathologic observation, histomorphometric analysis and immunohistochemistry with fibronectin and CD44 antibody. The results obtained from this study were as follows: 1. Histopathogically, findings, newly formed bone was seen at 3 weeks control group and became lamellar bone at 12 weeks. At 6 weeks, lipocytes were observed in bone marrow space. Thickness of regenerated trabecular bone increased till 6 weeks after then, that decreased gradually. 2. By histomorphometric analysis, marrow bone density and contact ratio of marrow bone to implant decreased significantly from 8 to 12 weeks in experimental group compared to control group and also total bone to implant contact ratio decreased significantly from 4 to 12 weeks in experimental group compared to control group. 3. Fibronectin immunoreactivity was very strong at 3 and 4 weeks control group. And after that reduced gradually. But it was continuously strong from 1 to 12 weeks experimental group. 4. CD44 immunoreactivity was very strong in the newly formed osteoblasts at 3 and 4 weeks control group. But it reacted minimally later. However, it reacted continuously strong from 3 to 12 weeks experimental group. From these results, bone to implant contact ratio decreased gradually from 4 weeks in adrenalectomized group compared to control group. CD44 and fibronectin immunoreactivities were strong at all times in adrenalectomized rats. Therefore, it could be stated that immature bone remained continuously for a long time and not readily proceeded into mature status.