• 대한치과교정학회지
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• 제26권2호
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• pp.163-174
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• 1996

본 실험은 서로 다른 기전으로 골흡수를 억제한다고 추정되는 약제인 bisphosphonate와 indomethacin을 백서에 투여한 후 교정력을 이용한 치아이동시 약제가 골개조에 미치는 영향을 밝히고자 시행되었다. 동일한 조건에서 사육된 체중 260-300g의 웅성백서(Sprague-Dawley계)를 대조군, bisphosphonate 투여군 및 indomethacin 투여군으로 분류하고 각 군은 다시 장치를 장착한 실험측과 장치를 장착하지 않은 대조측으로 분류하였다. Bisphosphonate(6.3mg/kg,$2.52x10^{-2}mol/L$)와 indomethacin(9mg/kg, $2.52x10^{-2}mol/L$)은 교정장치 장착 6시간 전, 1시간 전 및 24시간 후에 복강내 주사하였으며, 교정력이 가해진 시점으로부터 72시간이 경과한 후 파골세포수를 측정하고 조직학적인 성상을 관찰하였다. 또한 혈액을 채취한 후 혈청 acid phosphatase 및 lactate dehydrogenase 양을 측정하여 다음과 같은 성적을 얻었다. 실험측의 파골세포수는 장치장착 1시간 전에 투여한 bisphosphonate군과 indomethacin군에서 가장 적게 나타났으며, 다른 시간의 약물 투여군은 대조군과 차이가 없었다. 대조측의 파골세포수는 실험측보다 현저히 적게 나타났으며, 대조군 및 약물투여군간에 차이가 없었다. 대조군과 6시간 전 및 24시간 후에 투여한 indomethacin군은 심한 골흡수 양상을 보인 반면, 1시간전 indomethacin군 및 모든 bisphosphonate군에서는 골흡수의 정도가 적었다. 파골세포의 주름변연과 투명대는 대조군 및 indomethacin군에서 가장 뚜렷하게 나타났으며, bisphosphonate 투여군에서는 일부 파골세포들이 무딘 세포돌기만을 내거나 골표면에 부착하지 않고 있는 경우가 많았다. Bisphosphonate와 indomethacin 투여군 모두에서 acid phosphatase 및 lactate dehydrogenase 값이 대조군보다 낮았으며, acid phosphatase 값은 bisphosphonate군이 indomethacin군보다 낮았으나 lactate dehydrogenase 값은 차이가 없었다. 이상의 결과로 bisphosphonate는 파골세포의 수 및 대사활동을 감소시키며 indomethacin은 파골세포의 수를 감소시킴을 알 수 있었다. 또한 두 약물을 비교하면 bisphosphonate는 indomethacin에 비해 골흡수 억제효과가 더 크며 투여시간에 따른 제약도 더 적은 것으로 사료된다.

• International Journal of Oral Biology
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• 제36권1호
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• pp.37-42
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• 2011

The working mechanism of bisphosphonate on bone cells is unclear despite its powerful inhibitory activity on bone resorption. The differentiation and activation of osteoclasts are essential for bone resorption and are controlled by the stimulatory RANKL and inhibitory OPG molecules. Teeth exhibit a range of movement patterns during their eruption to establish their form and function, which inevitably accompanies peripheral bone resorption. Hence, the mandible, which contains the teeth during their eruption processes, is a good model for revealing the inhibitory mechanism of bisphosphonate upon bone resorption. In the present study, RANKL and OPG expression were examined immunohistochemically in the mandible of rats with developing teeth after alendronate administration (2.5 mg/kg). The preeruptive mandibular first molars at postnatal days 3 to 10 showed the developing stages from bell to crown. No morphological changes in tooth formation were observed after alendronate administration. The number of osteoclasts in the alveolar bone around the developing teeth decreased markedly at postnatal days 3, 7 and 10 compared with the control group. RANKL induced strong positive immunohistochemical reactions in the dental follicles and stromal cells around the mandibular first molar. In particular, many osteoclasts with strongly positive reactions to RANKL appeared above the developing mandibular first molars at postnatal days 3 and 10. Immunohistochemical reactions with RANKL after alendronate administration were weaker than the control groups. However, the immunohistochemical reactivity to OPG was stronger after alendronate administration, at postnatal days 3 and 10. These results suggest that alendronate may decrease bone resorption by regulating the RANKL/OPG pathway in the process of osteoclast formation, resulting in a delay in tooth eruption.

• 대한치과교정학회지
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• 제51권6호
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• pp.366-374
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• 2021

Objective: This study investigated the impact of a single piezocision in the maxillary alveolar process on the speed of tooth movement. The null hypothesis was that the speed of tooth movement will be equal with and without piezocision. Methods: All maxillary molars on one side were moved against the combined incisors in 10 ten-week-old male Wistar rats. Under general anesthesia, a force of 25 cN was applied on either side using a Sentalloy closed coil spring. After placing the orthodontic appliance, vertical corticision was performed using a piezotome under local anesthesia, 2 mm mesial from the mesial root of the first molar on a randomly selected side; the other side served as the control. At the beginning of the treatment, and 2 and 4 weeks later, skull micro-computed tomography was performed. After image reconstruction, the distance between the mesial root of the first molar and the incisive canal, and the length of the mesial root of the first maxillary molar were measured. Moreover, the root resorption score was determined as described by Lu et al. Results: Significantly higher speed of tooth movement was observed on the corticision side; thus, the null hypothesis was rejected. The loss of root length and root resorption score were significantly more pronounced after piezocision than before. A strong correlation was observed between the speed of tooth movement and root resorption on the surgical side, but the control side only showed a weak correlation. Conclusions: Piezocision accelerates orthodontic tooth movement and causes increased root resorption.

• Journal of Periodontal and Implant Science
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• 제47권4호
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• pp.194-210
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• 2017

Purpose: The aim of the present study was to evaluate the healing of post-extraction sockets following alveolar ridge preservation clinically, radiologically, and histologically. Methods: Overall, 7 extraction sockets in 7 patients were grafted with demineralised bovine bone mineral and covered with a porcine-derived non-crosslinked collagen matrix (CM). Soft tissue healing was clinically evaluated on the basis of a specific healing index. Horizontal and vertical ridge dimensional changes were assessed clinically and radiographically at baseline and 6 months after implant placement. For histological and histomorphometric analysis, bone biopsies were harvested from the augmented sites during implant surgery 6 months after the socket preservation procedure. Results: Clinically, healing proceeded uneventfully in all the sockets. A trend towards reduced horizontal and vertical socket dimensions was observed from baseline to the final examination. The mean width and height of resorption were 1.21 mm (P=0.005) and 0.46 mm (P=0.004), respectively. Histologically, residual xenograft particles ($31.97%{\pm}3.52%$) were surrounded by either newly formed bone ($16.02%{\pm}7.06%$) or connective tissue ($50.67%{\pm}8.42%$) without fibrous encapsulation. The CM underwent a physiological substitution process in favour of well-vascularised collagen-rich connective tissue. Conclusions: Socket preservation using demineralised bovine bone mineral in combination with CM provided stable dimensional changes of the alveolar ridge associated with good reepithelialisation of the soft tissues during a 6-month healing period.

• International Journal of Oral Biology
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• 제37권2호
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• pp.63-68
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• 2012

It has been documented that SPA0355 exerts antiinflammatory effects via the inhibition of nuclear factor-kappaB activation. In present study, we investigated the inhibitory effects of SPA0355 on periodontitis in an animal model. Periodontitis was induced by ligation of the cervix of the 1st molar in the left mandible in rats. After ligature, the rats were randomly divided into four groups and topically applied with SPA0355 (0.5, 1, and 2%) or the vehicle alone once daily for 10 days. Body weight and food intake were measured daily throughout the experimental period. At day 10 post-ligature, the infiltration of inflammatory cells and distance of the cementoenamel junction (CEJ) to the alveolar bone crest (ABC) in the distal area of ligatured tooth were estimated histopathologically. No changes in body weight or food intake were found between the control and SPA0355 groups. The degree of inflammation was decreased in all three SPA0355 application groups. A decrease CEJ-ABC distance was observed in the 0.5% and 1% SPA0355 groups. These results indicate that SPA0355 inhibits the infiltration of inflammatory cells and alveolar bone resorption and suggests its potential as a therapeutic agent for periodontitis.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제41권5호
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• pp.232-239
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• 2015

Objectives: The purpose of this study was to estimate the volumetric change of augmented autobone harvested from mandibular body cortical bone, using cone-beam computed tomography (CBCT) and three-dimensional reconstruction. In addition, the clinical success of dental implants placed 4 to 6 months after bone grafting was also evaluated. Materials and Methods: Ninety-five patients (48 men and 47 women) aged 19 to 72 years were included in this study. A total of 128 graft sites were evaluated. The graft sites were divided into three parts: anterior and both posterior regions of one jaw. All patients included in the study were scheduled for an onlay graft and implantation using a two-stage procedure. The dental implants were inserted 4 to 6 months after the bone graft. Volumetric stability was evaluated by serial CBCT images. Results: No major complications were observed for the donor sites. A total of 128 block bones were used to augment severely resorbed alveolar bone. Only 1 of the 128 bone grafts was resorbed by more than half, and that was due to infection. In total, the average amount of residual grafted bone after resorption at the recipient sites was $74.6%{\pm}8.4%$. Conclusion: Volumetric stability of mandibular body autogenous block grafts is predictable. The procedure is satisfactory for patients who want dental implants regardless of atrophic alveolar bone.

• 대한치과보철학회지
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• 제54권1호
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• pp.21-27
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• 2016

국소의치 수복에서는 의치 장착에 의한 잔존 조직의 위해를 최소한으로 억제하는 것이 중요하다. 잔존 구강조직에 위해를 가하는 첫 번째 요인은 잔존치 및 치조제의 기능력 부담이며 두 번째는 구강 위생관리 부족에 의한 영향이다. 이중관을 활용한 국소의치는 rigid support를 통해 치조제에 미치는 부담을 경감시킬 수 있으며, 외관과 의치부에 부착되는 치태 및 침착물을 구강 외에서 쉽고 확실하게 관리할 수 있다. 또한 내관인 지대치 역시 모든 방향에서 청소가 용이해 변연 치은의 건강에 유리하다. 본 증례에서는 심한 치조골 흡수 및 불량한 구강 위생관리를 보이는 부분 무치악 환자에서 이중관을 이용한 국소의치로 상, 하악을 수복하여 기능과 심미, 구강 위생 관리 측면에서 만족할 만한 결과를 얻을 수 있었다.

• Journal of Periodontal and Implant Science
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• 제39권1호
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• pp.71-76
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• 2009

Purpose: Many researches showed loss of alveolar bone in fresh extraction socket and even in case of immediate implant placement. The aim of this study was to evaluate the effect of non-resorbable barrier membrane on the change of buccal and lingual alveolar bone in immediate implant placement into periapically infected extraction sockets. Materials and methods: Immediate implants were placed into artificially induced periapical lesion of mandibular premolars after complete debridement using buccal bone defect made by a 6mm trephine bur in 4 mongrel dogs. Before flap repositioning, a non-resorbable barrier membrane was placed on the buccal defect in the experimental group. No membrane was placed in the control group. In 12 weeks after placement, the dogs were sacrificed and undecalcified histologic specimens were prepared. The vertical distance from the smooth-rough surface interface(SRI) to gingiva, 1st bone contact and bone crest were measured in buccal and lingual side. The horizontal thicknesses of gingiva and bone at 0, 1, 2 and 3mm below SRI were measured. Results: The buccal bone was resorbed more than lingual bone in both groups and there was statistical significance(p<0.05). The distances from SRI to 1st bone contact were $2.45{\pm}2.35\;mm$ in experimental group and $4.49{\pm}3.10\;mm$ in control group. In all vertical level, lingual bone was thicker than buccal bone(p<0.05). Conclusion: Buccal bone was reduced more than lingual bone in immediate implant placement into periapically infected extraction sockets. Placement of non-resorbable barrier membrane reduced the buccal bone resorption. However there was no statistical significance.

• Restorative Dentistry and Endodontics
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• 제6권1호
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• pp.7-16
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• 1980

The author observed the periodontal tissue reactions to the root canal sealers after root perforations were made intentionally in dogs. The perforations were made on 74 teeth from 7 dogs. The experiments were performed in two different modes of procedure: In Group I, the perforations were made through the root canal to the alveolar bone. In Group II, the perforations were made from site of alveolar bone to the root canals. The perforated canals in Group I were filled with gutta-percha and root canal cements; Calxyl (Calcium Hydroxide in Ringer's solution), Zinc Oxide -Eugenol cement (Z.O.E.), Kerr sealer (Rickert's paste) and AH 26 (Epoxy Resin preparations). The perforated canals in Group II were sealed with Calxyl, Z.O.E, Kerr sealer and AH26. Histologic examinations of periodontal tissue reactions were observed at various time intervals. The results were as follows; l. Cementum deposition on the perforated root surface in Group II cases showed slightly earlier than that of Group I. Healing tendency of injured alveolar bone in Group II was greater than that of Group I. 2. According to the time increase after experiment, the cementum deposition on the site of perforated dentin in Group II with intact pulp was notably thickened. Secondary dentin deposition on the root canal surface where the dentinal tubles were cut was also found in similar pattern. 3. In the cases of perforated canals sealed with Calxyl both in Group I and Group II, It revealed the earliest cementum-deposition among 4 different root canal cements. In the cases of perforated canals sealed with Kerr sealer and AH26, the cementum-deposition on the root surface was not found. 4. Proliferation of epithelium around the perforated area was first seen at 5-week cases in Group I, and at 3-week cases in Group II. 5. In all cases, dentin resorption on the site of perforated root surface was always occured.

• Journal of Korean Dental Science
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• 제12권1호
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• pp.29-37
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• 2019

Purpose: This study was aimed to compare the survival and success rates, and long-term crestal bone loss according to the use of 2 connection types of dental implants (submerged-USII and non-submerged-SSII; Osstem $Implant^{(R)}$) by analyzing the change in alveolar bone height after 1 year under load and during final follow-up period. Materials and Methods: Between December 2004 and August 2008, patients with two types of Osstem implants (USII and SSII) were retrieved retrospectively. A total of 92 patients with 284 implants (USII=60, SSII=224) was finally selected. Their mean follow-up period was 7.5 years. The mesial and distal alveolar crestal bone changes were measured using radiographic images and the average was calculated at 1 year after loading and during final follow-up period. Result: Among the 284 implants, 4 USII and 7 SSII implants were removed, indicating 93.3% and 96.9% survival rates. Of the survived implants, mean crestal bone loss 1 year after loading was 0.39 mm for USII and 0.19 mm for SSII (P=0.018). During the final follow-up, mean crestal bone loss was 0.63 mm and 0.35 mm for USII and SSII, respectively, without statistical significance (P=0.092). According to the criteria for the success and failure of the implant by Albreksson and colleagues, final success rate was estimated as 86.7% for USII and 91.5% for SSII, respectively. Conclusion At 1 year after loading, the average crestal bone loss was significantly different between USII and SSII; however, both types met the criteria for implant success. During the final follow-up, both groups showed insignificant bone resorption patterns and did not show any pathological clinical symptoms. Therefore, both implants exhibited high long-term stability.