• The Journal of Advanced Prosthodontics
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• 제5권4호
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• pp.374-381
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• 2013

PURPOSE. The purpose of this study was to evaluate the effect of alendronates on bone remodeling around titanium implant in the maxilla of rats. MATERIALS AND METHODS. The maxillary first molars were extracted and customized-titanium implants were placed immediately in thirty male Sprague-Dawley rats. The rats were divided into experimental (bisphosphonate) group and control group. At 4 weeks after implantation, the rats in the bisphosphonate group were subcutaneously injected with alendronate three times a week for 6 weeks where as the rats in control group were injected with saline. The rats were sacrificed at 1, 2, 3, 4, or 6 weeks after starting of injection and maxillary bones were collected subsequently. Alveolar bone remodeling around the implants were evaluated by radiographic and histologic analysis. Microarray analysis and immunohistomorphologic analysis were also performed on one rat, sacrificed at 6 weeks after starting of injection, from each group. Statistical analysis was performed using repeated measures analysis of variance and independent t test at a significance level of 5%. RESULTS. There was no statistically significant difference in the bone area (%) around implant between the bisphosphonate group and the control group. However, the amount of empty lacuna was significantly increased in the bisphosphonate group, especially in the rats sacrificed at 4 weeks after starting of injection compared to that of the corresponding control group. The bisphosphonate group showed the same level of TRAP positive cell count, osteocalcin and angiopoietin 1 as the control group. CONCLUSION. Alendronate may not decrease the amount of osteoclast. However, the significantly increased amount of empty lacuna in the bisphosphonate group may explain the suppression of bone remodeling in the bisphosphonate group.

• The Journal of Advanced Prosthodontics
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• 제8권5호
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• pp.363-371
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• 2016

PURPOSE. On maxillofacial tumor patients, oral implant placement prior to postoperative radiotherapy can shorten the period of prosthetic reconstruction. There is still lack of research on effects of post-implant radiotherapy such as healing process or loading time, which is important for prosthodontic treatment planning. Therefore, this study evaluated the effects of post-implant local irradiation on the osseointegration of implants during different healing stages. MATERIALS AND METHODS. Custom-made implants were placed bilaterally on maxillary posterior edentulous area 4 weeks after extraction of the maxillary first molars in Forty-eight Sprague-Dawley rats. Experimental group (exp.) received radiation after implant surgery and the other group (control) didn't. Each group was divided into three sub-groups according to the healing time (2, 4, and 8 week) from implant placement. The exp. group 1, 2 received 15-Gy radiation 1 day after implant placement (immediate irradiation). The exp. group 3 received 15-Gy radiation 4 weeks after implant placement (delayed irradiation). RESULTS. The bone mineral density (BMD) was significantly lower in the immediate irradiation groups. BMD was similar in the delayed irradiation group and the control group. The irradiated groups exhibited a lower bone-to-implant contact ratio, although the difference was not statistically significant. The irradiated groups also exhibited a significantly lower bone volume and higher empty lacuna count than the control groups. No implant failure due to local irradiation was found in this study. CONCLUSION. Within the limits of this study, the timing of local irradiation critically influences the bone healing mechanism, which is related to loading time of prostheses.

• 대한치과보철학회지
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• 제51권3호
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• pp.175-182
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• 2013

연구 목적: 본 연구에서는 알렌드로네이트 투여기간의 차이가 백서의 상악 제 1대구치 발치와의 초기 창상치유에 미치는 영향을 알아보고자 하였다. 연구 재료 및 방법: 4주령 Sprague Dawley Rat (Body weight 130-140 g) 15마리를 이용하여 알렌드로네이트(Merial Inc., Parramatta, Australia) 투여군(실험군)과 투여하지 않은 대조군으로 나누고 실험군은 다시 투여기간에 따라 1주 투여군부터 2주 투여군, 4주 투여군, 6주 투여군까지 총 4개의 실험군으로 나눴다. 실험군에 정해진 시기(발치 5 주전, 발치 3주전, 발치 1주전, 발치 시)부터 발치 1주 후까지 알렌드로네이트를 1 mg/kg의 농도로 주 3회 피하주사 한 후 6주 투여군과 대조군에서 한 개체씩을 이용하여 미세배열(microarray)분석을 실시하였고, 다른 시편들을 이용하여 조직학적 분석을 시행하였다. 발치와 내에서의 신생골의 형성 비율과 발치와 주위 골에서 활성을 잃은 뼈에 대해 분석하였고, 파골세포 표지자인 TRAP 염색을 하여 분석하였다. 통계적인 분석으로 크루스컬-왈리스 검정(Kruskal Wallis test)을 실시하였다(${\alpha}=.05$). 결과:발치 후 1주 시점에서의 발치와 내에서의 신생골의 생성 비율은 대조군보다 ($16.77%{\pm}1.36%$) 4주 투여군($14.99%{\pm}6.26%$)에서 더 낮게 나오는 경향은 있었지만 유의 하지는 않았다. 투여기간이 증가할수록 활성을 잃은 골수강(empty lacuna)의 수는 증가하였고, TRAP positive cell 수는 감소하는 경향이 있으나 유의하지는 않았다. 결론: 본 예비실험을 통해서 알렌드로네이트의 투여기간이 증가할수록 신생골의 생성 비율이 감소되고 활성을 잃은 뼈들이 많아지며 파골세포의 수는 줄어드는 경향이 있음을 알 수 있었으나 통계적으로 유의차는 없었다.

• 대한골관절종양학회지
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• 제9권2호
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• pp.190-199
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• 2003

목적: Holmium-166은 류마티스성 관절염 및 간암 치료에서 이미 임상적으로 사용이 보고된 방사성 동위원소이다. 본 연구는 holmium-166-chitosan 복합체를 외과적으로 생체에 투입하여 임상에 적용 가능한 방법을 연구하고, 투여량과 기간, 투여 부위에 따른 조직학적 반응 정도를 정성 및 정량 분석하여 임상적용의 기초로 활용하는 것이다. 재료 및 방법: Absorbable gelatin sponge에 액체상태의 holmium-166-chitosan 복합체를 50 ${\mu}l}$ 도포하여 고형제로 만들었다. 최종 삽입전에 caliberator로 측정한 방사선량은 약 1.5 mCi였다. Wistar종 흰쥐에 외과적 시술을 통하여 대퇴근육 내부와, 그리고 대퇴골에 접하게 holmium-166-chitosan 복합체가 부착된 gelatin sponge를 삽입 후 봉합하였다. 대퇴 근육내와 대퇴골에 투여한 후 2주, 4주, 6주에 육안 및 현미경 소견하에서 조직 괴사의 깊이, 조직 변화의 양상, 삽입된 gelatin sponge의 변화 등을 관찰하였다. 결과: 2주후의 현미경 소견상 holmium-166과의 접촉면에서는 정상 근육세포의 모양을 찾아 볼 수 없을 만큼 심한 괴사 소견을 보였고 근육세포의 퇴화 및 재생, 근육간 부종, 염증세포의 침윤 소견을 보였으며 유발된 괴사의 깊이는 평균 3.3 mm 였다. 대퇴골에서는 holmium-166과의 접촉면에 있는 골피질은 골소강내 골세포의 소실이 관찰되었고 골수강내의 골수 세포도 파괴되고 섬유화 또는 염증성 반응을 보였다. 괴사의 깊이는 평균 2.9 mm 였다. 4주 때 근육에서는 석회화와 보다 심해진 섬유화 소견이 추가 되었고 괴사의 깊이는 평균 3.3 mm 였다. 골조직에서도 골수강의 섬유화가 더 증가되었고 괴사의 깊이는 평균 3.3 mm였다. 경과 관찰 6주 군에는 연부 조직의 위축과 섬유화의 증가, 육아조직의 형성, 염증 소견의 소실 등이 관찰되었다. 결론: Holmium-166-chitosan 복합체를 생체 흡수 가능한 gelatin sponge에 부착시킨 후 실험동물에 삽입한 결과, 실험동물의 사망을 유발하지도 않았으며 상처의 괴사, 염증, 감염 등의 부작용이 전혀 없어, 생체에 외과적 적용이 가능하였다. 유발된 조직 괴사의 범위는 약 3 mm로 미리 예측한 정도에 근접하는 것으로 악성종양 치료에 임상적 적용이 가능할 것으로 생각한다.

• 대한골관절종양학회지
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• 제5권1호
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• pp.9-16
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• 1999

A new method of limb sparing by resection, extracorporeal irradiation and reimplantation has several theoretical advantages. This method preserves the mobility of a joint and avoids the problem of loosening or breakage of tumor prosthesis. This study involved using extracorporeal irradiated autogenous joint transplantation for reconstruction after en bloc resection, and observed the periods of functional union and histological changes in irradiated tissue of the knee joint. This study also aimed to clarify whether the degeneration of articular cartilage is induced in rabbits by a single 50Gy dose of irradiation at the knee joint. Twenty New Zealand rabbits about three kilograms were randomized into two groups of 10 rabbits each. In group 1, as control, we resected the knee joint followed by reimplantation without irradiation. Group 2 received extracorporeal irradiation on the resected knee joint followed by reimplantation. Following are the results of these observations. The osteotomy site showed external callus formation in the roentgenographic finding eight weeks after reimplantation. There was marked degenerative changes in the collagen fiber of the irradiated anterior cruciate ligament and meniscus during the fourth week, but new blood-vessel formation was observed in the vicinity. There was degenerative changes in the collagen fiber of articular cartilage treated extracorporeal irradiation at four and eight weeks in the scanning electron micrographic findings. These findings was in contrast to those of subchondral bone which showed decreased cellularity and empty lacuna at four and eight weeks. Autoradiography demonstrated active [$^3H$]uridine incorporation by irradiated chondrocyte at eight weeks after reimplantation. These results indicate that when destruction of the articular cartilage and soft tissue of the knee joint is not severe, extracorporeal irradiation and reimplantation can be used with several advantage in maintaining movement of the joint while avoiding problems of tumor prosthesis and rejection, and therefore extracorporeal irradiated autogenous joint transplantation can be used as a limb-sparing procedure for temporary biological spacer in the childhood bone tumor around the knee.