• Journal of Periodontal and Implant Science
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• 제28권1호
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• pp.145-160
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• 1998

The ultimate goal of periodontal therapy is the regeneration of periodontal tissue which has been lost due to destructive periodontal disease, and numerous kinds of materials and techniques have been developed to achieve this goal. Bone grafts include autografts, allografts, xenografts and synthetic grafts. Among the synthetic grafts, bioactive glass has been used in dentistry for more than ten years and Fetner reported improved new bone formation and more amount of new attachment after grafting PerioGlas, a kind of bioactive glass, in 2-wall defects of monkeys in 1994. It Is well known that 1-wall defects have less osteogenic potential and more epithelial migration, so we need to study the erect of bioactive glass in 1-wall dejects in dogs. The present study evaluates the effect of bioactive glass on the epithelial migration, alveolar bone regeneration, cementum formation and gingival connective tissue attachment in intrabony detects of dogs. Four millimeter deep and four millimeter wide 1-wall defects were surgically cheated in the mesial aspects of premolars. The test group received bioactive glass with a flap procedure and the control underwent flap procedure only. Histologic analysis after 8 weeks of healing revealed the following results: 1. The height of gingival margin was 1.30{\pm}0.73mm$ above CEJ in the control and $1.40{\pm}0.78mm$ in the test group. There was no statistically significant difference between the two group. 2. The length of epithelial growth (the distance from CEJ to the apical end of JE) was $1.74{\pm}0.47mm$ in the control and $1.12{\pm}0.36mm$ in the test group. These was a statistically significant difference between the two groups (P<0.01). 3. The length of new cementum was $2.06{\pm}0.73mm$ in the control and $2.62{\pm}0.37mm$ in the test group. There was no statistically significant difference between the two groups. 4. The length of new bone was $1.83{\pm}0.74mm$ in the control and $2.39{\pm}0.59mm$ in the test group. There was no statistically significant difference between the two groups. These results suggest that the use of bioactive glass 1-wall intrabony defects has significant effect on the prevention of junctional epithelium migration, but doesn't have any significant effect on new bone and new cementum formation.

• Journal of Periodontal and Implant Science
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• 제27권1호
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• pp.217-234
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• 1997

The purpose of present study is to compare the effect of treatment using $Guidor^{(R)}$ as a barrier membrane in conjunction with platelet-derived growth factor and insulin like growth factors on experimental dehiscence defects. Following the resection of premolar crowns, roots were submerged. After 12 weeks of healing period, experimental dehiscence defects of 4mm in height and 4mm in width were surgically created on the mid-facial aspect of the lower premolar roots in each of 4 adult dogs. After root planning and demineralization of the root surface with citric acid, the control groups received 4% methylcellulose gel only, the test group I received 4% methylcellulose gel and were covered by $Guidor^{(R)}$ and the test group II were treated with PDGF and IGF and 4% methylcellulose gel with $Guidor^{(R)}$ coverage. Histological and histomorphometric analysis following 8 weeks of healing revealed the following results. 1. The new bone formation showed no statistically significant difference in all groups with $0.59{\pm}0.82mm$($14.03{\pm}19.60%$) for control, $0.70{\pm}0.39mm$($16.30{\pm}9.01%$) for group I, $0.87{\pm}0.76mm$($18.74{\pm}16.03%$) for group II. 2. The new cementum formation showed no statistically significant difference in all groups with $0.54{\pm}0.48mm$($l6.38{\pm}14.57%$) for control, $0.95{\pm}0.38mm$($23.43{\pm}9.30%$) for group I, $1.01{\pm}0.75mm$($22.10{\pm}16.ll%$) for gorup II. 3. The root resorption showed statistically significant differences betweenthe control group and all test groups(p<0.05) with $2.11{\pm}0.53mm$($52.93{\pm}12.32%$) for control, $0.63{\pm}0.27mm$($15.32{\pm}7.05%$) for group I, $0.89{\pm}0.33mm$ ($19.26{\pm}7.11%$) for group II. On the bases of these results, there were no statistically difference between treatment using resorbable membrane and resorbable membrane in conjunction with PDGF and IGF in the dehiscence defects, where it was difficult to maintain space. The use of membrane seemed to be more effective in the inhibition of root resorption.

• Journal of Periodontal and Implant Science
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• 제24권1호
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• pp.64-86
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• 1994

The authors have transplanted periodontally involved roots which had been root planed into healthy and periodontally involved extraction sockets, and studied the root resorption patterns as well as its effect on new bone formation and wound healing. Alveolar bone around mandibular premolars of 6 adult dogs has been surgically removed, followed by ligation of orthodontic elastic wires for 8 weeks inducing chronic periodontal disease. After removing the crown portions, roots were extracted, and notches were made on the root surfaces discriminating healthy and periodontally involved areas using burs. Controls and experimental groups were divided as follows. Control I : Transplantation of periodontally involved root into healthy extraction sockets. Control II : Transplantation of periodontally involved root into diseased extraction sockets. Experimental group I : Transplantation of root planed roots into healthy extraction sockets. Experimental group II : Transplantation of root planed roots into diseased extraction sockets. Extraction sockets were sutured after transplantations, completely submerging the roots. Healing progress was histologically observed at 2nd, 8th, 12th, and 20th weeks, and the results were as follows ; 1. No inflammation or infection within the extraction sockets had been observed in all groups throughout the experimental period. 2. Reversal lines were observed at week 2 in all groups, clearly discriminating socket walls and new bone, and numerous blood vessels were observed in the new bone trabeculae. 3. Experimental groups showed markedly less root resorption compared to the controls at week 2, but as time progressed, severe resorptions were present in all groups. 4. Localized areas of new bone ankylosis were observed, and the rest of the areas showed collagen fiber insertion with new bone formation at its periphery. 5. No clear differences were found in healing and alveolar bone regeneration between healthy and diseased extraction sockets. 6. The amount of root resorption and ankylosis had increased up to week 8 and 12, showing ankylosis of new bone and the roots. However, no further increase in ankylosis was observed at week 20. 7. Most of the cementum on healthy roots was directly ankylosed to new bone at week, 2, and were gradually resorbed and replaced by new bone thereafter. These results appear to indicate that root planing may inhibit early root resorption of transplanted roots, but gradual replacement by alveolar bone and collagen fibers eventually occur. Condition of the roots or presence of disease in extraction sockets do not appear to make marked differences in alveolar bone regeneration process.

• Journal of Periodontal and Implant Science
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• 제39권2호
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• pp.119-128
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• 2009

Purpose: The aim of this study was to evaluate the stemness of cells from canine dental tissues and bone marrow. Methods: Canine periodontal ligament stem cells (PDLSC), alveolar bone stem cells (ABSC) and bone marrow stem cells(BMSC) were isolated and cultured. Cell differentiations (osteogenic, adipogenic and chondrogenic) and surface antigens (CD146, STRO-1, CD44, CD90, CD45, CD34) were evaluated in vitro. The cells were transplanted into the subcutaneous space of nude mice to assess capacity for ectopic bone formation at 8 weeks after implantation. Results: PDLSC, ABSC and BMSC differentiated into osteoblasts, adipocytes and chondrocytes under defined condition. The cells expressed the mesenchymal stem cell markers differently. When transplanted into athymic nude mice, these three kinds of cells with hydroxyapatite /${\beta}$- tricalcium phosphate (HA/TCP) carrier showed ectopic bone formation. Conclusions: This study demonstrated that canine dental stem cells have stemness like bone marrow stem cells. Transplantation of these cells might be used as a therapeutic approach for dental stem cell-mediated periodontal tissue regeneration.

• Journal of Chest Surgery
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• 제30권11호
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• pp.1055-1061
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• 1997

실험동물에서의 폐이식수술에서 비침습성 흉부전산화 단층 촬영을 이용하여 이식폐의 기능평가지표의 가치를 분석해 보고자 한국산 잡종견을 이용하여 좌측일측폐이식술후 7일 이상 생존시킨 성견을 대상으로 급성거부반응 및 허혈-재관류손상, 감염 등의 소견을 병리조직소견과 함께 관찰하였다. 실험견은 총 22마리에서 11마리씩 공급견과 수용견으로 나누어 시행하였다. 공급견의 심폐블록보존은 Modified Euro-Collins (MEC) 용액과 low potassium dextran glucose(UDG)용액을 이용하여 $10^{\circ}C에서$ 20시간 (1례에서 4시간 보존) 이상 냉장보관하였다 폐이식술후, 흉부 X-선과 연속적인 컴퓨터단층촬영을 수술 직후와 술후 3일 및 7일째 각각 시행하였다. 11례의 이식견 중 2례에서 급성거부반응을 보였고 전산화단층촬영상 폐침윤정도가 수술 직후 중등도였다가 수술 3일째 확장성으로 변하였다. 결론적으로 일측 폐이식성견의 실험적인 모델에서 이식폐장의 기능평가지표로서 컴퓨터단층촬영을 이용 하며 다른 평가지표와 유사한 소견을 얻었고 폐의 감염과 거부 반응의 구별은 단층촬영의 음영의 비교만으 로 감별이 용이하지 않았으며 다른 평가지표 및 폐생검\ulcorner 확인으로 조기거부반응의 진단 가능성을 평가할 수 있었다.

• 대한치과교정학회지
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• 제38권1호
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• pp.5-12
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• 2008

교정용 미니스크류의 원추 형태가 식립 후 시기별 안정성에 미치는 영향을 알아보기 위해, 시기별 제거 토오크 및 동요도와 조직시편분석을 시행하였다. 성견 6마리의 하악 협측골에 원통형과 원추형 교정용 미니스크류 (Biomaterials Korea, Seoul, Korea) 48개를 식립하고, 식립 시 식립 토오크와 동요도를 측정하고 3주, 12주 동안 교정력을 부여한 후, 제거 시 제거 토오크와 동요도를 측정하였다. 식립 토오크는 원통형 미니스크류에서 13.6 Ncm, 원추형 미니스크류에서 22.3 Ncm 로 원추형 미니스크류에서 높은 식립 토오크가 측정되었다 (p < 0.001). 식립 3주째 제거 토오크는 원통형 미니스크류에서 5.7 Ncm, 원추형 미니스크류에서 9.1 Ncm 로 유의한 차이가 관찰되었다 (p < 0.05). 식립 12주째 원추형 미니스크류의 제거 토오크는 3.6 Ncm 로 유의하게 감소하여 (p < 0.05) 원통형 미니 스크류의 4.2 Ncm 와 유의한 차이를 보이지 않았다. 이상의 결과로 미니스크류의 원추 구조는 식립 토오크를 유의하게 증가시켜 식립 후 3주간 안정성에 도움이 되었으나, 12주 후 안정성에 있어서는 원통형 미니스크류와 유사하였음을 시사한다.

• 대한치과교정학회지
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• 제40권3호
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• pp.167-175
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• 2010

Periotest$^{(R)}$는 보철용 임플랜트 식립 3 - 4개월 후 골유착 정도를 평가하기 위해 사용되는 동요도 측정 기기로 교정용 미니임플랜트 안정성 평가에 적용가능성이 높다. 본 연구는 교정용 미니임플랜트의 안정성 평가를 위해 Periotest$^{(R)}$의 유효성을 검증하고자 하였다. 성견 다섯 마리의 상악, 하악 협측골에 교정용 미니임플랜트를 식립하고, 식립 시 식립토오크와 동요도를 측정하고 12주 동안 교정력을 부여한 후, 제거 시 제거 토오크와 동요도를 측정하였다. 동요도 (Periotest$^{(R)}$ value, PTV) 측정은 재현성을 위해 동일 부위에 2회 측정하였다. PTV와 다른 변수와의 상관성 분석을 위해 모든 실험견은 CT 촬영 후 식립 부위의 골밀도와 피질골 두께를 계측하였다. 동요도 측정에 대한 재현성은 0.96의 상관계수를 나타내 매우 높았으며 (p < 0.001) 골밀도와 피질골 두께에 있어 하악골 협측치조골이 상악골에 비해 유의하게 컸다 (p < 0.05). 12주 동안 PTV 값은 -3.2에서 4.8의 범위를 나타내며 모든 임플랜트는 임상적으로 안정적이었다. 식립 시 PTV 값은 하악에서 식립 토오크(-0.51), 골밀도(-0.48), 피질골 두께(-0.42)와 상관성이 있었으나 (p < 0.05), 상악에서는 상관성이 없었다. 제거 시 PTV 값은 하악에서 제거 토오크(-0.66)와 상관성이 있었으며(p < 0.05), 상악에서는 상관성이 없었다. 이상의 결과는 Periotest$^{(R)}$를 이용하여 교정용 미니임플랜트의 안정성을 간접적으로 평가할 수 있으나 골밀도가 높고 피질골이 두꺼운 부위에서 제한적으로 응용할 수 있음을 시사한다.

• Journal of Periodontal and Implant Science
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• 제36권1호
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• pp.27-37
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• 2006

Although the main purpose of periodontal treatment to regenerate is the complete regeneration of periodontal tissue due to periodontal disease, most of the treatment cannot meet such purpose because healing by long epithelial junction. Therefore, diverse materials of resorbable and non-resorbable have been used to regenerate the periodontal tissue. Due to high risk of exposure and necessity of secondary surgical procedure when using non-resorbable membrane, guided tissue regeneration using the resorbable membrane has gain popularity, recently. However, present resorbable membrane has the disadvantage of not having sufficient time to regenerate date to the difference of resorption rate according to surgical site. Meanwhile, other than the structure stability and facile manipulation, acellular dermal matrix has been reported to be a possible scaffold for cellular proliferation due to rapid revascularization and favorable physical properties for cellular attachment and proliferation. The purpose of this study is to estimate the influence of acellular dermal matrix on periodontal ligament, cementum and alveolar bone when acellular dermal matrix is implanted to 1-wall alveolar bone defect. 4 dogs of 12 to 16 month old irrelevant to sex , which below 15Kg of body weight, has been used in this study. ADM has been used for the material of guided tissue regeneration. The 3rd premolar of the lower jaw was extracted bilaterally and awaited for self-healing. subsequently buccal and lingual flap was elevated to form one wall intrabony defect with the depth and width of 4mm on the distal surface of 2nd premolar and the mesial surface of 4th premolar. After the removal of periodontal ligament by root planing. notch was formed on the basal position. Following the root surface treatment, while the control group had the flap sutured without any treatment on surgically induced intrabony defect. Following the root surface treatment, the flap of intrabony defect was sutured with the ADM inserted while the control group sutured without any insertion. The histologic specimen was observed after 4 and 8 weeks of treatment. The control group was partially regenerated by periodontal ligament, new cementum and new alveolar bone. the level of regeneration is not reached on the previous formed notch. but, experimental group was fully regenerated by functionally oriented periodontal ligament fiber. new cementum and new alveolar bone. In conclusion, we think that ADM seems to be used by scaffold for periodontal ligament cells and the matrix is expected to use on guided tissue regeneration.

• Journal of Periodontal and Implant Science
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• 제35권4호
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• pp.823-837
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• 2005

The purpose of this study was to study the histopathological correlation between the use of platelet-rich plasma and enamel matrix protein used in conjunction with xenograft. compared to a control group with regards to bone regeneration at the grade III furcation area in beagle dogs. Control group was treated with bovine derived bone $powder(Biocera^{(R)})$, and experimental I group was treated with bovine derived bone powder and Platelet-rich plasma and experimental II group was treated with bovine derived bone powder and Enamel matrix $protein(Emdogain^{(R)})$. The regeneration rate of bone formation was observed and compared histopathologically at 2. 4, and 8 weeks after surgery. The results were as follows: 1. In control group and both experimental groups. inflammatory cells were observed but, new bone formation wasn't. 2. In control group, new cementum on the notch was found in 4 weeks, less mature periodontal ligament when compared to that of experimental group was found and cementum formation was great but, regeneration couldn't be seen in 8 weeks. 3. Experimental I group. new bone formation in the area adjacent to alveolar bone and graft material surrounded by more dense connective tissue were found in 4 weeks. New bone formation up to crown portion was found and periodontal ligament was aligned functionally and cementum more mature. 4. Experimental II group, new bone formation was found under the defect area in 4 weeks and new bone formation around graft material in 8 weeks, too, and there were a number of fibroblasts, blood vessels, acellular cementum, which was less mature when compared to that of experimental I group, and dense collagen fiber like which normal periodontal ligament has in periodontal ligament of experimental II group in 8 weeks. 5. As a result of histologic finding, bone formation rate were 18.0${\pm}$7.87%(control group), 34. 05${pm}$7.25%(experimental I group), 19.33 ${pm}$5.15%(experimental II group) in 4 weeks and 21.89${pm}$1.58%(control group), 38.82${pm}$3.2(experimental I group), 37.65${pm}$9.22%(experimental II group) in 8 weeks. 6. Statistically significant ratio of bone formation was observed in experimental I group in 4 weeks and in experimental II group in 8 weeks. When experimental I group was compared to experimental II group, the ratio of bone formation in experimental I group was higher than that in experimental II group in 4 weeks(p<0.05). This results suggest that platelet-rich plasma showed more new bone formation than enamel matrix protein within 4 weeks. And use of enamel matrix protein in the treatment of periodontal bone defects starts to enhance regeneration after 8 weeks in beagle dogs.

• Journal of Periodontal and Implant Science
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• 제28권2호
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• pp.249-264
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• 1998

The present study evaluates the effects of calcium sulfate and DFDB on alveolar bone regeneration and cementum formation and connective tissue adhesion in intrabony angulated 1 wall defects of dogs. Four millimeter-deep angulated one-wall intrabony defects were surgically created in the mesial & distal aspects of premolars and with flap operaion alone(control group), with calcium sulfate(experimental group 1), with composit graft of 50% calcium sulfate and 50% DFDB(experimental group 2), with DFDB alone(experimental group 3). Histologic analysis following 8 weeks of healing revealed the following results: 1. The lengths of connective tissue adhesion was $1.05{\pm}0.48mm$ in the control, $1.30{\pm}0.67mm$ in the test group I, $0.97{\pm}0.22mm$ in the test group II and $0.93{\pm}0.15mm$ in the test group III. There was no statistical significance between control and all experimental groups. 2. Changes in alveolar bone level was $0.97{\pm}0.27mm$ in the control group, $1.45{\pm}0.42mm$ in the test group I, $2.00{\pm}0.33mm$ in the test group II, $1.88{\pm}0.34mm$ in the test group III. There was no statistically significant difference between control and experimental group I. There was a statistically significant difference between the control and experimental group II,III.(p<0.05). There was no statistically significant difference between all experimental group. 3. Cementum formation was $1.13{\pm}0.17mm$ in the control, $1.78{\pm}0.31mm$ in the test group I, $2.17{\pm}0.38mm$ in the test group II, $2.15{\pm}0.47mm$ in the test group III with statistically significant differences between control group and all experimental group(P<0.05). There was no statistically significant differences between all experimental group. These results suggest that the use of composit graft of 50% calcium sulfate and 50% DFDB and DFDB alone in angulated 1 wall intrabony defects has little effects on connective tissue adhesion, but has significant effects on new bone and new cementum formations.