• Journal of Periodontal and Implant Science
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• 제31권2호
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• pp.299-315
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• 2001

Application of membranes for guided tissue regeneration(GTR) have been confined to the subgingival barrier functions; however, many studies have provided evidence that some drugs, including tetracycline, initially can promote the growth of periodontal ligament or alveolar bone in peridontal therapy. Osseous regeneration in periodontal defects is increased by local administration of tetracycline due to its anti-collagenolytic effect, which enhances bone-forming ability via osteoblast cell chemotaxis and reduced bone resorption. The aim of this study was to evaluate effects of tetracycline loaded poly-L-lactide(PLLA) barrier membranes for guided bone regenerative potential. Tetracycline was incorporated into the PLLA membrane with the ratio 10% to PLLA by weight. Ability to guided bone regeneration of the membranes were tested by measuring new bone in the tibial defects($7{\times}10{\times}5\;mm^3$) of the beagle dog for 4,5, and 6 weeks. In control, drug-unloaded PLLA membranes were used in same size of defect. In histologic finding of the defect area, a few inflammatory cells were observed in both groups. These membrane were not perforated by connective tissue and maintained their mechanical integrity for the barrier function for 4-6 weeks. New bone formation was greater in defects covered by tetracycline-loaded membrane than in defects covered by drug- unloaded membranes. In bone regeneration guiding potential test, tetracycline-loaded membrane was more effective than drug- unloaded membranes(p<0.05). These results suggest that tetracycline-loaded PLLA membranes potentially enhance guided bone regenerative efficacy and might be a useful barrier for GTR in periodontal treatment.

• 대한치과교정학회지
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• 제33권5호
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• pp.399-405
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• 2003

빠르며 정확하고 안전한 치아이동을 목표로 삼고 있는 교정치료에서 새로운 패러다임이라고 여겨지는 피질골 절제술과 견인 골형성술을 응용한 치아이동에 대하여 알아보았다. 일반적인 방법으로는 어렵거나 불가능하다고 여겨지는 치아의 함입 이동을 피질골 절제술과 견인 골형성술을 응용하여 도모하였다. 전치군 및 구치군 각각의 함입 이동 증례를 통해 피질골 절제술과 견인 골형성술의 적용 술식, 견인장치 등을 논하고 그 효과를 파악하였다. 빠른 치아이동과 이에 따른 교정치료 기간의 감소가 가능하고 기존의 교정치료로는 어려웠던 치아이동을 도모할 수 있었으며 무리한 치아이동 시 발생할 수 있는 치근 흡수나 치주조직의 파괴 같은 부작용도 줄일 수 있었다.

• International Journal of Stem Cells
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• 제16권1호
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• pp.93-107
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• 2023

Background and Objectives: Chronic periodontitis can lead to alveolar bone resorption and eventually tooth loss. Stem cells from exfoliated deciduous teeth (SHED) are appropriate bone regeneration seed cells. To track the survival, migration, and differentiation of the transplanted SHED, we used super paramagnetic iron oxide particles (SPIO) Molday ION Rhodamine-B (MIRB) to label and monitor the transplanted cells while repairing periodontal bone defects. Methods and Results: We determined an appropriate dose of MIRB for labeling SHED by examining the growth and osteogenic differentiation of labeled SHED. Finally, SHED was labeled with 25 ㎍ Fe/ml MIRB before being transplanted into rats. Magnetic resonance imaging was used to track SHED survival and migration in vivo due to a low-intensity signal artifact caused by MIRB. HE and immunohistochemical analyses revealed that both MIRB-labeled and unlabeled SHED could promote periodontal bone regeneration. The colocalization of hNUC and MIRB demonstrated that SHED transplanted into rats could survive in vivo. Furthermore, some MIRB-positive cells expressed the osteoblast and osteocyte markers OCN and DMP1, respectively. Enzyme-linked immunosorbent assay revealed that SHED could secrete protein factors, such as IGF-1, OCN, ALP, IL-4, VEGF, and bFGF, which promote bone regeneration. Immunofluorescence staining revealed that the transplanted SHED was surrounded by a large number of host-derived Runx2- and Col II-positive cells that played important roles in the bone healing process. Conclusions: SHED could promote periodontal bone regeneration in rats, and the survival of SHED could be tracked in vivo by labeling them with MIRB. SHED are likely to promote bone healing through both direct differentiation and paracrine mechanisms.

• Journal of Periodontal and Implant Science
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• 제47권5호
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• pp.312-327
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• 2017

Purpose: This study assessed marginal bone remodeling and soft tissue esthetics after the loading of single bone-level implants in the anterior maxilla. Methods: An open, single-arm observational clinical trial with 3 years of follow-up was performed, including 22 implants. The patients presented with a single tooth gap in the anterior maxilla (tooth positions 14-24), with natural or restored adjacent teeth. An implant was placed at least 8 weeks post-extraction and healed submerged for 6 weeks. After the second-stage operation, a fixed provisional prosthesis was provided. The final restoration was placed 6 months after the provisional restoration. The time of the provisional crown connection was considered to be the baseline in this study. Esthetic parameters and the marginal bone level were assessed at 6, 12, 24, and 36 months. Results: All implants were well integrated in the bone. A statistically significant increase was found in the mean implant stability quotient between the time of the provisional prosthesis and the time of the final prosthesis. Most implants (95.5%) revealed marginal bone resorption (<0.5 mm), and just 1 implant (4.5%) showed a change of 2.12 mm from baseline to 36 months (mean $0.07{\pm}0.48mm$), while the crestal bone level decreased significantly, from $2.34{\pm}0.93mm$ at baseline to $1.70{\pm}1.10mm$ at 36 months. The facial gingival margin and papilla were stable and the esthetic scores indicated high patient and dentist satisfaction. Conclusions: Platform-switching bone-level implants placed in maxillary single-tooth gaps resulted in successful osseointegration with minimal marginal bone resorption. The peri-implant soft tissue was also esthetically satisfying and stable.

• 구강회복응용과학지
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• 제39권4호
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• pp.214-221
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• 2023

잔존 치조제의 흡수가 심하게 진행된 환자에서 안정된 의치를 제작하기 위해서는 여러가지 요소를 고려해야 한다. 그 중 하나는 중립대(Neutral zone)로, 기능하는 동안 구강 안에서 밖으로 향하는 혀의 압력과 밖에서 안으로 향하는 볼과 입술의 압력이 평형을 이루는 잠재적인 영역으로 정의된다. 만약 치조제의 흡수가 심한 경우에 통상적으로 잔존 치조제 상방에 치아를 배열한다면 치아는 기존 위치보다 설측에 위치하게 된다. 따라서 혀의 기능공간을 침범하게 되어 혀가 후방으로 위치하게 되고, 설측 변연의 봉쇄가 깨져 의치를 탈락시키는 요인으로 작용하게 된다. 또한 상·하악의 치조제를 잇는 치조정간선을 상정하고 저작력을 치조정간선에 일치시키도록 상·하악 인공치를 배열하는 것 또한 의치의 안정에 중요하다. 따라서 불량한 잔존 치조제를 지닌 환자에게 중립대 인상 및 치조제 관계 분석을 이용해 의치를 제작하여 좋은 임상 결과를 얻었기에 보고하는 바이다.

• 치위생과학회지
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• 제23권4호
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• pp.282-295
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• 2023

Background: Secretory leukocyte protease inhibitor (SLPI) protects tissues from proteases and promotes cell proliferation and healing. SLPI also reduces periodontal inflammation and alveolar bone resorption by inhibiting proinflammatory cytokine expression in rat periodontal tissues and osteoblasts. However, little is known of the role of SLPI in the expression of osteoclast regulatory factors from osteoblasts, which are crucial for the interaction between osteoblasts and osteoclasts. Therefore, we aimed to determine the effects of SLPI on the regulation of osteoclasts and osteoblasts in LPS-treated alveolar bone and osteoblasts. Methods: Periodontitis was induced in rats using LPS. After each LPS injection, SLPI was injected into the same area. Immunohistochemical analysis was performed with antibodies against SLPI, RANKL, OPG, and Runx2 in the periodontal tissue. RT-PCR and western blotting were performed to determine the expression levels of SLPI, RANKL, OPG, and Runx2 in LPS- and SLPI/LPS-treated MC3T3-E1 cells. SLPI/LPS-treated MC3T3-E1 cells were also stained with Alizarin Red S. Results: Immunohistochemical analysis showed that the expression levels of SLPI, OPG, and Runx2 were higher while that of RANKL was lower in the LPS/SLPI group relative to those in the LPS group. The mRNA and protein expression of SLPI, OPG, and Runx2 was higher in SLPI/LPS/MC3T3-E1 cells than in LPS/MC3T3-E1 cells, and RANKL expression was lower. During differentiation, OPG and Runx2 protein levels were higher whereas RANKL levels were lower in SLPI/LPS/MC3T3-E1 than in LPS/MC3T3-E1 cells on days 0, 4, 7, and 10. In addition, mineralization and matrix deposition were higher in SLPI/LPS/MC3T3-E1 than in LPS/MC3T3-E1 on days 7 and 10. SLPI decreased RANKL expression in LPS-treated alveolar bone and osteoblasts but increased the expression of OPG and Runx2. Conclusion: SLPI can be considered as a regulatory molecule that indirectly regulates osteoclast activation via osteoblasts and promotes osteoblast differentiation.

• Journal of Periodontal and Implant Science
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• 제41권5호
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• pp.211-217
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• 2011

Purpose: The marginal bone levels around implants following restoration are used as a reference for evaluating implant success and survival. Two design concepts that can reduce crestal bone resorption are the microthread and platform-switching concepts. The aims of this study were to analyze the placement of microthreaded and platform-switched implants and their short-term survival rate, as well as the level of bone around the implants. Methods: The subjects of this study were 27 patients (79 implants) undergoing treatment with microthreaded and platform-switched implants between October 2008 and July 2009 in the Dental Hospital of Yonsei University Department of Periodon-tology. The patients received follow-up care more than 6 months after the final setting of the prosthesis, at which time periapical radiographs were taken. The marginal bone level was measured from the reference point to the lowest observed point of contact between the marginal bone and the fixture. Comparisons were made between radiographs taken at the time of fixture installation and those taken at the follow-up visit. Results: During the study period (average of 11.8 months after fixture installation and 7.4 months after the prosthesis delivery), the short-term survival rate of microthreaded and platform-switched implants was 100% and the marginal bone loss around implants was $0.16{\pm}0.08$ mm, the latter of which is lower than the previously reported values. Conclusions: This short-term clinical study has demonstrated the successful survival rates of a microthread and platform-switched implant system, and that this system is associated with reduced marginal bone loss.

• Journal of Periodontal and Implant Science
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• 제40권6호
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• pp.283-288
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• 2010

Purpose: The aim of this case report is to present a case of incomplete bone formation after sinus augmentation. Methods: A patient having alveolar bone resorption of the maxillary posterior edentulous region and advanced pneumatization of the maxillary sinus was treated with sinus elevation using deproteinized bovine bone in the Department of Periodontology, Kyung Hee University School of Dentistry and re-evaluated with computed tomography (CT) follow-up. Results: Even though there were no significant findings or abnormal radiolucency on the panoramic radiograph, incomplete bone formation in the central portion of the augmented sinus was found fortuitously in the CT scan. The CT scan revealed peri-implant radiolucency in the apical portion of the implant placed in the augmented maxillary sinus. Nevertheless, the dental implants placed in the grafted sinus still functioned well at over 15 months follow-up. Conclusions: The result of this case suggests that patients who received maxillary sinus augmentation may experience incomplete bone formation. It is possible that 1) osteoconductive graft material with poor osteogenic potential, 2) overpacking of graft material that restricts the blood supply, and 3) bone microbial contamination may cause the appearance of incomplete bone formation after sinus augmentation. Further studies are needed to elucidate the mechanism of this unexpected result and care must be taken to prevent it.

• Journal of Periodontal and Implant Science
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• 제24권3호
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• pp.633-648
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• 1994

Synthetic bone graft materials have been used for the regeneration of periodontal tissue lost due to periodontal disease, but the limitations of these materials had prompted the use of composite grafts. Among those, a composite graft of calcium carbonate(CC) and calcium sulfate(CS) is one of those materials that has not been studied extensively. CC, which is extracted from a natural coral, is known to possess osteoconductive property. SC can play an adjunctive role in the regeneration of bone tissue, and has shown good resorbability and biocompatibility. This study was conducted in order to investigate the effects of CC and CS composite graft to the regeneration of bone in the intrabony defects of dogs. 3-wall intrabony defects ub size of $4mm{\times}4mm{\times}4mm$ were created in the alveolar bone in the premolar areas. Then those defects that were treated with root planning only were designated as control, while the experimental group 1 and 2 each received the CC and CS composite grafts in the ratio of 8 : 2 and 5 : 5 the animals were sacrificed after 8weeks and the specimens were histologically analyzed. The results were as follows ; 1. No inflammation or foreign body reaction were observed in all subjects. CS has not been seen due to complete resorption, and resorption pattern of CC was observed. 2. Significant differences(p<0.05) in new cementum formation were observed between control($1.42{\pm}0.64mm$) and experimental groups(group 1 ; $2.53{\pm}0.94mm$, group 2 ; $2.23{\pm}0.96mm$) but the difference between the two experimental groups was not significant. 3. Significant differences(p<0.01) in new bone formation were observed between control($0.59{\pm}0.55mm$) and experimental groups(group 1 ; $2.27{\pm}0.61mm$, group 2 ; $2.05{\pm}0.56mm$) but the difference between the two experimental groups was not significant. 4. The extent of apical epithelial migration has shown no significant difference between control($1.18{\pm}1.24mm$) and experimental groups(group 1 ; $0.51{\pm}0.54mm$, group 2 ; $0.73{\pm}0.70mm$). 5. The extent of bone formation was generally limited to the extent of cementum formation for all groups, and significant correlation was found in the amount of bone formation and cementum formation in experimental group 1.(Co.=0.86, p<0.01) These results suggest that the composite graft of CC and CS is biocomplatible and effective in the new bone and new cementum formations. In the case of 3-wall intrabony defects of dogs, the composite ratio of 8 : 2 and 5 : 5 had shown no significant differences in the healing.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제26권6호
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• pp.666-671
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• 2000

Objectives: This study evaluated the availability of mandibular symphysis corticocancellous block grafts in patients treated for reconstruction of intraoral jaw defects. Materials & Methods: 8 patients with mandibular and maxillary bony defects were treated with corticocancellous block of symphysis. The types of defects included 4 pathologic jaw defects and 4 vertical and/or horizontal alveolar deficiencies. The age ranged from 13 to 45 years. Additional treatments such as plate fixation, alloplastic bony substitutes, and/or barrier membrane application were perfomred. They were evaluated for complications and healing of defects. Follow-up period ranged from 6 to 15 months. Results: 2 patients experienced complications such as wound dehiscence and mild resorption of exposed bone. None of the patients needed secondary operation. Paresthesia of lip, chin, and teeth were recovered completely by 6 months postoperatively. Reconstructed wound showed favorable healing and bony consolidation. Conclusion: Corticocancellous block of mandibular symphysis can be used for the reconstruction of a variety of intraoral local jaw defects selectively. Advantages were easy fixation of graft, possibility of restoration of original alveolar contour, and decreased donor site morbidity.