• The Journal of the Korean dental association
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• v.47 no.6
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• pp.364-372
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• 2009

치주 질환으로 인하여 소실된 치주조직을 재생시키려는 여러 술식이 많이 연구되고있다. 그 중 bioactive factor의 적용은 치주조직의 재생에 있어서 우수한 치료법으로 평가되고 있으며, 이를 수용부에 적절히 적용하기 위한 운반체로 생체친화적인 중합체가 이용되고 있다. 본 연구의 목적은 PLGA를 Inorganic filler에 혼합시킨 재료를 성견의 일벽성 골내낭에 적용하여 이 재료의 생체 친화성과 생체 흡수도를 보고자 하는 것이다. 5마리의 비글견에서 제 3 소구치를 모두 발치한 뒤, 8주간의 치유기간이 지나고 제 2 소구치 원심면과 제 4 소구치 근심면에 5mm 깊이, 4mm폭의 일벽성 골내낭을 형성하였다. 좌측 defect에는 PLGA/inorganic filler matrix를 이식하였고 우측에는 아무것도 이식하지 않은 대조군으로 나누어 술 후 8주에 희생하여 치유 결과를 조직학적으로 비교 관찰하였다. 조직학적 분석 결과, 모든 결손부에서 염증의 소견이 관찰되지 않았으며 치근흡수와 유착은 발견되지 않았다. 백악질과 치조골, 치주인대를 포함한 치주조직의 재생에 있어서 대조군, 실험군 간에 조직학적으로 치유양상에 있어 차이를 많이 보이지 않았으며 PLGA/inorganic filler matrix는 8주 내에 완전히 흡수되어 결합조직이나 신생골내에서 그 흔적을 발견할 수 없었다. 이러한 결과는 PLGA/inorganic filler matrix는 생체친화성 및 생체흡수성이 우수한 재료로서 치주 조직의 재생 치료에 있어서 신체활성인자의 scaffold로 사용될 수 있는 가능성을 보여주었다.

• Journal of Periodontal and Implant Science
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• v.26 no.4
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• pp.779-797
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• 1996

The present study investigated the effects of variations in decalcification time of demineralized freeze-dried bone on the osteogenic potential of DFDB. Sixteen 3-wall intrabony defects with 4mm depth were surgically created in the mesial aspect of upper and lower anterior teeth of 4 dogs. Following the flap procedure, three test groups with 4 defects each received either freeze-dried bone graft (Group I), demineralized freeze-dried bone graft decalcified for 12hours (Group II), or demineralized freeze-dried bone graft decalcified for 24hours(Group III). The rest of the four defects received the flap procedure-only as the control group. The healing was histologically analyzed after 14 weeks on the length of connective tissue adhesion, new bone formation and new cementum formation. The results were as follows: 1. The length of connective tissue adhesion showed no statistically significant difference in all groups with $0.62{\pm}0.14mm$ for Control, $0.42{\pm}0.11mm$ for Group I, $0.63{\pm}0.43mm$ for Group II and $0.52{\pm}0.11mm$ for Group III. 2. The new bone formation showed no statistically significant difference in all groups with $3.17{\pm}0.24mm$ for Control. $3.15{\pm}0.56mm$ for Group I. $3.22{\pm}0.36mm$ for Group II, and $3.28{\pm}0.74mm$ for Group III. 3. The new cementum formation showed no statistically significant difference in all groups with $4.19{\pm}0.46mm$ for Control, $3.23{\pm}0.64mm$ for Group I, $4.13{\pm}1.82mm$ for Group II. and $3.13{\pm}0.62mm$ for Group III.

• Journal of Periodontal and Implant Science
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• v.38 no.1
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• pp.7-14
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• 2008

Purpose: Chitosan & chitosan derivative(eg. membrane) have been studied in periodontal regeneration, and recently many studies of chitosan have reported good results. If chitosan's effects on periodontal regeneration are enhanced, we can use chitosan in many clinical and experimental fields. For this purpose, this study reviewed available literatures, evaluated comparable experimental models. Materials and Methods: Ten in vivo studies reporting chitosan's effects on periodontal tissue regeneration have been selected by use of the 'Pubmed' and hand searching. Results: 1. In Sprague Dawley rat calvarial defect models, amount of newly formed bone in defects showed significant differences between chitosan/chitosan-carrier/chitosan-membrane groups and control groups. 2. In beagle canine 1-wall intrabony defect models, amount of new cementum and new bone showed significant differences between chitosan/chitosan-membrane groups and control groups. The mean values of the above experimental groups were greater than the control groups. Conclusion: The results of this study have demonstrated that periodontal regeneration procedure using chitosan have beneficial effects, which will be substitute for various periodontal regenerative treatment area. One step forward in manufacturing process of chitosan membrane and in use in combination with other effective materials(eg. bone graft material or carrier) may bring us many chances of common use of chitosan in various periodontal area.

• Journal of Periodontal and Implant Science
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• v.40 no.3
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• pp.125-131
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• 2010

Purpose: Among available biomaterials, bioceramics have drawn special interest due to their bioactivity and the possibility of tailoring their composition. The degradation rate and formulation of bioceramics can be altered to mimic the compositions of the mineral phase of bone. The aim of this study was to investigate the bone formation effect of amorphous calcium phosphate glass cement (CPGC) synthesized by a melting and quenching process. Methods: In five male beagle dogs, $4{\times}4$ mm 1-wall intrabony defects were created bilaterally at the mesial or distal aspect of the mandibular second and fourth premolars. Each of the four defects was divided according to graft materials: CPGC with collagen membrane (CM), biphasic calcium phosphate (BCP) with CM, CM alone, or a surgical flap operation only. The dogs were sacrificed 8 weeks post-surgery, and block sections of the defects were collected for histologic and histometric analysis. Results: There were significant differences in bone formation and cementum regeneration between the experimental and control groups. In particular, the CPGC and BCP groups showed greater bone formation than the CM and control groups. Conclusions: In conclusion, CPGC was replaced rapidly with an abundant volume of new bone; CPGC also contributed slightly to regeneration of the periodontal apparatus.

• 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.34 no.1
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• pp.113-126
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• 2004

연구목적 : 이번 실험의 목적은 외과적으로 형성된 성견의 1면 골내낭에 새롭게 제조된, Ca/P 비율이 0.6인 비결정성 calcium phosphate를 적용하였을 때 치주조직의 재생에 미치는 영향을 평가하는 것이다. 연구방법 : 6마리 성견의 양측 하악 제2소구치의 원심면, 제4소구치의 근섬면에 외과적으로 1면 골내낭을 형성하여 치은박리소파술을 시행한 부위를 대조군으로, calcium phosphate만을 이식한 부위를 실험 1군, calcium phosphate와 GTR을 동반한 부위를 실험 2군으로 설정하고 실험하여 술 후 8주에 치유결과를 조직학적으로 관찰하였다. 결론 : 1. 접합상피의 치근단 이동은 대조군에서 결손부 깊이의 30.90 ${\pm}$ 9.92%, 실험 1군에서 결손부 깊이의 24.08 ${\pm}$ 9.12%, 실험 2군에서 결손부 깊이의 38.68 ${\pm}$ 12.22%로 나타났으며 대조군과 실험 1,2군간에 통계적 유의차는 없었다. 2. 결합조직 유착은 대조군에서 결손부 깊이의 36.38 ${\pm}$ 9.03%, 실험 1군에서 결손부 깊이의 26.96 ${\pm}$ 4.24%, 실험 2군에서 결손부 깊이의 27.87 ${\pm}$ 9.70%로 나타났으며 대조군과 실험 1,2군간에 통계적 유의차는 없었다. 3. 신생백악질 형성은 대조군에서 결손부 깊이의 32.92 ${\pm}$ 10.51%, 실험 1군에서 결손부 깊이의 49.16 ${\pm}$ 12.70%, 실험 2군에서 결손부 깊이의 39.62 ${\pm}$ 12.14%로 나타났으며 대조군과 실험 1군간에 통계적 유의차가 있었다. 4. 신생골 형성은 대조군에서 결손부 깊이의 27.24 ${\pm}$ 7.49%, 실험 1군에서 결손부 깊이의 43.51 ${\pm}$ 13.34%, 실험 2군에서 결손부 깊이의 36.47 ${\pm}$ 15.11%로 나타났으며 대조군과 실험 1, 2군간에 통계적 유의차는 없었다. 이상의 결과에서 볼 때, calcium phosphate glasses는 신생골 형성에는 통계적으로 유의차는 없었지만 상당히 증가된 양상을 보였고 신생백악질 형성에는 크게 기여함을 알수 있었다.

• Journal of Periodontal and Implant Science
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• v.41 no.4
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• pp.176-184
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• 2011

Purpose: The final goal of regenerative periodontal therapy is to restore the structure and function of the periodontium destroyed or lost due to periodontitis. However, the role of periosteum in periodontal regeneration was relatively neglected while bone repair in the skeleton occurs as a result of a significant contribution from the periosteum. The aim of this study is to understand the histological characteristics of periosteum and compare the native periosteum with the repaired periosteum after elevating flap or after surgical intervention with flap elevation. Methods: Buccal and lingual mucoperiosteal flaps were reflected to surgically create critical-size, "box-type" (4 mm width, 5 mm depth), one-wall, intrabony defects at the distal aspect of the 2nd and the mesial aspect of the 4th mandibular premolars in the right and left jaw quadrants. Animals were sacrificed after 24 weeks. Results: The results from this study are as follows: 1) thickness of periosteum showed difference as follows (P<0.05): control group ($0.45{\pm}0.22$ mm)> flap-elevation group ($0.36{\pm}0.07$ mm)> defect formation group ($0.26{\pm}0.03$ mm), 2) thickness of gingival tissue showed difference as follows (P<0.05): defect formation group ($3.15{\pm}0.40$ mm)> flap-elevation group ($2.02{\pm}0.25$ mm) > control group ($1.88{\pm}0.27$ mm), 3) higher cellular activity was observed in defect formation group and flap-elevation groups than control group, 4) the number of blood vessles was higher in defect formation group than control group. Conclusions: In conclusion, prolonged operation with increased surgical trauma seems to decrease the thickness of repaired periosteum and increase the thickness of gingiva. More blood vessles and high cellular activity were observed in defect formation group.