• 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.33 no.2
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• pp.225-246
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• 2003

Recent study on the enamel matrix derivatives explained on the effects of new bone and new attachment formation in infrabony pocket of periodontal defects. The purpose of this study was to investigate on the biological effects of enamel matrix derivatives to attachment, proliferation and activation of periodontal ligament and osteoblast cells, After treatment of osteoblast and PDL cells with various Emdogain concentration level(0.03${\mu}g$/ml, 3${\mu}g$/ml, 300${\mu}g$/ml), activation of osteogenetic factor, calcified nodule formation and measuring alkaline phosphatase activity(ALP) were performed. 1. Both osteoblast and PDL cell showed increasing initial cell attachment with 300${\mu}g$/ml Emdogain concentration. 2. At the level of 300${\mu}g$/ml, accelerated proliferation of oseoblast and PDL cell was appeared. 3. As Emdogain's concentration increased, increased ALP activation of osteoblast was shown. In case of PDL cell, Emdogain increased ALP activation prominently at the level of 300${\mu}g$/ml. 4. No statistically significant activating change were founded at all of the concentrations of Emdogain on the activating of transcript factor Runx2 for differentiating osteoblast. 5. At the level of 300${\mu}g$/ml, calcified nodule formation was increased prominently to compare with other concentration. These results indicated that Emdogain should activate initial attachment, proliferation and activation, but not on Runx2 activation and can be used for useful tool of the treatment of periodontal tissue regeneration.

• Journal of Periodontal and Implant Science
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• v.27 no.4
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• pp.845-866
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• 1997

Several experimental studies showed that the application of small amounts of electric current to bone stimulated osteogenesis at the site of the cathode and suggests that the application of electrical currents to periodontal defects could promote bone and cementum formation. The purpose of this study was to determine the effect of direct microcurrent to the periodontal regeneration of class III furcation defects in dogs. Class III furcation defects were surgically created on the third and the fourth premolars bilaterally in the mandibles of nine mongrel dogs. Experimental periodontitis were induced by placing small cotton pellets into the created defects for 3 weeks. The experimental sites were divided into three groups according to the treatment modalities: Group I-surgical debridement only; Group II-allogenic demineralized freeze dried bone grafting; Group III-allogenic demineralized freeze dried bone grafting and electrical stimulation. For fluorescence microscopic evaluation, calcein, oxytetracycline HCI and alizarin red were injected 2, 4 and 8 weeksfS days prior to sacrifice) after surgery. The animals were sacrificed in the 1st, 2nd, 4th and 8th week after periodontal surgery and the decalcified and undecalcified specimens were prepared for histological and histometrical examination. After the first and the second weeks, gingival recession was more severe in group I than groups II and III. After the fourth and the eighth weeks, there was no difference in the width of junctional epithelium and connective tissue attachment among the three groups, but the width of connective tissue attachment increased in group II at the eighth week, compared to the fourth week. The amount of bone repair in new attachment was significantly greater in group III, compared to groups I and II. New attachment formation was significantly greater in group III, compared to groups I and group II. These results suggest that electrical stimulation using microcurrent generator could be a useful tool for periodontal regenerative therapy in class III furcation defect.

• Journal of Periodontal and Implant Science
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• v.28 no.2
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• pp.263-273
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• 1998

For histologic observation of the regenerated bone following guided tissue regeneration (GTR) using ePTFE membranes with calcium carbonate implant and autogenous bone graft, biopsies were collected from 2 patients during 5-year-postoperative surgical reentry. In both combined cases with guided tissue regeneration in conjunction with calcium carbonate implant and autogenous bone graft, significant bone fill and gain in probing attachment level was observed. In histologic examination, specimen in GTR case with calcium carbonate grafting was composed of a dense bone containing vascular channel with lamellar structure and viable bone cells in lacunae, however considerable calcium carbonate particles remained unresorbed and isolated from regenerated bone by the dense cellular and fibrous connective tissue. No formative cells could be seen in contact with remained calcium carbonate particles. In GTR case with autogenous bone grafting, specimen show was composed of a dense lamellar bone containing vascular channel, which showed normal alveolar bone architectures. The present observation indicate that guided tissue regeneration in conjunction with grafting, especially autogenous bone graft, has highly osteogenic potential, however resorbable calcium carbonate granules were not completely resorbed at 5 year postimplantation.

• Journal of Periodontal and Implant Science
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• v.32 no.1
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• pp.213-224
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• 2002

The ultimate goal of periodontal disease therapy is to promote the regeneration of lost periodontal tissue, there have been many attempts to develop a method to achieve this goal, but none of them was completely successful. The purpose of this study was to compare the effects of treatment using BBP(R) with control treated by only modified Widman flap. 22 intrabony defects from 12 patients with chronic periodontitis were used for this study, 10 sites of them were treated with BBP(R) as experimental group and 12 site were treated by only modified Widman flap as control group. Clinical parameters including probing depth, gingival recession, bone probing depth and loss of attachment were recorded at 6 months later, and the significance of the changes was statistically analyzed. The results are as follows : 1. Probing depth of control(${\triangle}2.7{\pm}1.3mm$) and experimental group(${\triangle}3.6{\pm}1.8mm$) weres reduced with statistically significance(P<0.05), but this changes were not different between the two experiment, control group with statistically significance. 2. Gingival recession showed statistically significant increase in control group(${\triangle}2.1{\pm}1.2mm$)(P<0.05), but not in experimental group(${\triangle}0.5{\pm}0.7mm$), and this changes were different between the two experiment, control group with statistically significance(P<0.05). 3. Bone probing depth showed statistically significant decrease in experimental group(${\triangle}2.9{\pm}1.0mm$)(P<0.05), but not in control group(${\triangle}1.1{\pm}1.4mm$), and this changes were different between the two experiment, control group with statistically significance(P<0.05). 4. Loss of attachment showed statistically significant decrease in experimental group(${\triangle}3.1{\pm}1.7mm$), but not in control group(${\triangle}0.6{\pm}1.2mm$), and this changes were different between the two experiment, control group with statistically significance(P<0.05) On the basis of these results, treatment using BBP(R) improves the probing depth, bone probing depth and loss of attachment in intrabony defects.

• Journal of Periodontal and Implant Science
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• v.24 no.2
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• pp.219-237
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• 1994

The ultimate goal of clinical periodontal therapy is to achieve regeneration of a healthy connective tissue reattachment. Conventional therapy including scaling, root planing, gingival curettage, gingivectomy and flap procedures of various types results primarily in repair rather than regeneration of the periodontium. In order for periodontal regeneration to occur, progenitor periodontal ligament cells must migrate to the denuded root surface, attach to it, proliferate and mature into an organized and functional fibrous attachment apparatus. Polypeptide growth factors belong to a class of potent biologic mediators which regulate cell differentiation, proliferation, migration and metabolism. Insulin-like growth factor-I (IGF- I ) of these factors appear to have an important role in periodontal wound healing and bone formation. The purpose of this study is to evaluate the effects of IGF- I on the periodontal ligament cells to use as a regeneration promoting agent of periodontal tissue. Human periodontal ligament cells were obtained from periodontal tissue explants culture of the first premolar tooth extracted for the orthodontic treatment. Cells were cultured in Dulbecco's modified Eagle medium(DMEM) with 10% fetal bovine serum. Fourth to seventh passage cells were plated in 24 well tissue culture plates and medium changed to serum-free medium prior to addition of growth factors. Cell proliferation was measured by the incorporation of $[^3H]-thymidine$ into DNA, Protein synthesis was determined by measurement of $[^3H]-proline$ incorporation into collagenase-digestible protein(CDP) and noncollagenous protein(NCP) according to the method of Peterkofsky and Diegelmann (1971), And alkaline phosphatase activity was measured as one parameter of osteoblastic differentiation. The results were as follows : The DNA synthetic activity was increased in a dose-dependent manner with IGF- I except for 0.1ng/ml concentration of IGF- I At the concentration of 10, 100ng/ml, IGF- I significantly increased the DNA synthetic activity(P<0.05) The total protein, collagen and noncollagen synthesis was increased in a dose-dependent manner with IGF- I except for 0.1ng/ml concentration of IGF- I. At the concentration of 1, 10, 100ng/ml, IGF- I significantly increased the total protein, collagen and noncollagen synthesis activity(P<0.95, P<0.001). The % of collagen was not effected according to the concentration of IGF- I. The alkaline phosphatase activity was increased in a dose-, time-dependent manner with IGF- I (10, 100ng/ml). In conclusions, the present study shows that IGF- I has a potentiality to enhance the DNA synthesis of periodontal ligament cells with including the increase of the total protein and collagen synthetic activity. The use of IGF- I to mediate biological stimulation of periodontal ligament cells shows promise for future therapeutic applications.

• Journal of Periodontal and Implant Science
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• v.36 no.3
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• pp.757-765
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• 2006

Human periodontal ligament fibroblasts (hPDLF) are very important for curing the periodontal tissue because they can be differentiated into various cells. A tissue engineering approach using a cell-scaffold is essential for comprehending today's periodontal tissue regeneration procedure. This study examined the possibility of using an acellular dermal matrix as a scaffold for human periodontalligament fibroblast (hPDLF). The hPDLF was isolated from the middle third of the root of periodontally healthy teeth extracted for orthodontic reasons. The cells were cultured in a medium containing Dulbecco's modified Eagle medium supplemented with 10% fetal bovine serum at $37^{\circ}C$ in humidified air with 5% $CO_2$. The acellular dermal matrix(ADM) was provided by the US tissue banks(USA). Second passage cells were used in this study. The hPDLF cells were cultured with the acellular dermal matrix for 2 days, and the dermal matrix cultured by the hPDLF was transferred to a new petri dish and used as the experimental group. The control group was cultured without the acellular dermal matrix, The control and experimental cells were cultured for six weeks. The hPDLF cultured on the acellular dermal matrix was observed by Transmission Electron microscopy (TEM). Electron micrography shows that the hPDLF was proliferated on the acellular dermal matrix. This study suggests that the acellular dermal matrix can be used as a scaffold for hPDLF.

• Journal of Periodontal and Implant Science
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• v.38 no.sup2
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• pp.273-298
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• 2008

Purpose: The aim of this review is to introduce a novel bone-graft material for hard-tissue regeneration based on the calcium phosphate glass(CPG). Materials and Methods: CPG was synthesized by melting and subsequent quenching process in the system of CaO-$CaF_2-P_2O_5$-MgO-ZnO having a much lower Ca/P ratio than that of conventional calcium phosphates such as HA or TCP. The biodegradability and bioactivity were performed. Effects on the proliferation, calcification and mineralization of osteoblast-like cells were examined in vitro. Influence in new bone and cementum formations was investigated in vivo using calvarial defects of Sprague-Dawley rats as well as 1-wall intrabony defect of beagle dogs. The application to the tissue-engineered macroporous scaffold and in vitro and in vivo tests was explored. Results: The extent of dissolution decreased with increasing Ca/P ratio. Exposure to either simulated body fluid or fetal bovine serum caused precipitation on the surface. The calcification and mineralization of osteoblast-like cells were enhanced by CPG. CPG promoted new bone and cementum formation in the calvarial defect of Sprague-Dawley rats after 8 weeks. The macroporous scaffolds can be fabricated with $500{\sim}800{\mu}m$ of pore size and a three-dimensionally interconnected open pore system. The stem cells were seeded continuously proliferated in CPG scaffold. Extracellular matrix and the osteocalcin were observed at the $2^{nd}$ days and $4^{th}$ week. A significant difference in new bone and cementum formations was observed in vivo (p<0.05). Conclusion: The novel calcium phosphate glass may play an integral role as potential biomaterial for regeneration of new bone and cementum.

• Journal of Periodontal and Implant Science
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• v.27 no.3
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• pp.603-619
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• 1997

The use of laser in the treatment of soft tissue minimizes hemorrhage, provides better view of the operating field, and thereby minimizes operating time. Also, there will be far less post-operative swelling, pain and scar formation, and sterilizing effect are shown in some portions of the wound site. All these advantages of laser therapy contribute to its widespread use in the field of medicine and dentistry. Regarding such facts, we used CO2 laser of different watts in gingivectomy for white rats to compare initial healing process. For the control group, the least amount of output in performing gingivectomy(4watts) was offered, and for the experimental group, 6watts was given. Animals were sacrificed on the second, third days, 1 weeks, 2 weeks, and 3 weeks after operation, and their specimens were histologically analyzed. The following results were obtained: 1. Blood clot of small size was observed in both the control and experimental groups after two days, and no more thereafter. 2. In both the control and experimental groups, the inflammation zone size was the greatest after two days, and it decreased gradually to become almost invisble by the second week. The experimental group showed larger size of inflammation zone during second and third days: however, there was no difference after one week. 3. Granulation tissue in both the control and experimental groups showed gradual maturation with time, and by the second week, it was almost replaced by normal connective tissue. By the third week, complete healing pattern was observed. The experimental group showed larger granulation tissue than the control group until the third day, but there was no significant difference after one week. 4. In both the control and experimental groups, gingival epithelialization began on the second day. After one week, regeneration of rete peg and partial formation of junctional epithelium were observed: by the second week, keratinization of oral sulcular epithelium began, and it was completed by the third week.

• Journal of Periodontal and Implant Science
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• v.48 no.3
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• pp.182-192
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• 2018

Purpose: The purpose of the present study was to validate an experimental model for assessing tissue integration of titanium and zirconia implants with and without buccal dehiscence defects. Methods: In 3 dogs, 5 implants were randomly placed on both sides of the mandibles: 1) Z1: a zirconia implant (modified surface) within the bony housing, 2) Z2: a zirconia implant (standard surface) within the bony housing, 3) T: a titanium implant within the bony housing, 4) Z1_D: a Z1 implant placed with a buccal bone dehiscence defect (3 mm), and 5) T_D: a titanium implant placed with a buccal bone dehiscence defect (3 mm). The healing times were 2 weeks (one side of the mandible) and 6 weeks (the opposite side). Results: The dimensions of the peri-implant soft tissue varied depending on the implant and the healing time. The level of the mucosal margin was located more apically at 6 weeks than at 2 weeks in all groups, except group T. The presence of a buccal dehiscence defect did not result in a decrease in the overall soft tissue dimensions between 2 and 6 weeks ($4.80{\pm}1.31$ and 4.3 mm in group Z1_D, and $4.47{\pm}1.06$ and $4.5{\pm}1.37mm$ in group T_D, respectively). The bone-to-implant contact (BIC) values were highest in group Z1 at both time points ($34.15%{\pm}21.23%$ at 2 weeks, $84.08%{\pm}1.33%$ at 6 weeks). The buccal dehiscence defects in groups Z1_D and T_D showed no further bone loss at 6 weeks compared to 2 weeks. Conclusions: The modified surface of Z1 demonstrated higher BIC values than the surface of Z2. There were minimal differences in the mucosal margin between 2 and 6 weeks in the presence of a dehiscence defect. The present model can serve as a useful tool for studying peri-implant dehiscence defects at the hard and soft tissue levels.