• The korean journal of orthodontics
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• v.39 no.4
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• pp.203-212
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• 2009

Objective: The aim of this study was to evaluate the strain induced in the cortical bone surrounding an orthodontic microimplant during insertion in a self-drilling manner. Methods: A 3D finite element method was used to simulate the insertion of a microimplant (AbsoAnchor SH1312-7, Dentos Co., Daegu, Korea) into 1 mm thick cortical bone. The shape and dimension of thread groove in the center of the cortical bone produced by the cutting flute at the apical of the microimplant was obtained from animal test using rabbit tibias. A total of 3,600 analysis steps was used to calculate the 10 turns and 5 mm advancement of the microimplant. A series of remesh in the cortical bone was allowed to accommodate the change in the geometry accompanied by the implant insertion. Results: Bone strains of well higher than 4,000 microstrain, the reported upper limit for normal bone remodeling, were observed in the peri-implant bone along the whole length of the microimplant. Level of strains in the vicinity of either the screw tip or the valley part were similar. Conclusions: Bone strains from a microimplant insertion in a self-drilling manner might have a negative impact on the physiological remodeling of cortical bone.

• 대한치주과학회:학술대회논문집
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• 1999.11a
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• pp.87-88
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• 1999

• 대한치과보철학회:학술대회논문집
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• 2002.11a
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• pp.66-67
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• 2002

• Journal of Periodontal and Implant Science
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• v.39 no.1
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• pp.109-109
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• 2009

• Korean Journal of Cleft Lip And Palate
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• v.5 no.2
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• pp.117-122
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• 2002

성장기 환자에서의 각 부위별 임플란트 식려 시기를 요약해보면 다음과 같다. 1) 상악전방부 : 외상이나 선천적 결손을 해결하는 방법으로 임플란트를 사용하는 술식이 권장하지만 성장이 완료되지 않았기 때문에 야기되는 문제를 해결하기 위해 성장이 완료될 때까지 연기하는 것이 좋다. 2)상악 후방부: 수직적인 성장량이 최고 1cm까지 일어날 수 있으면 상악동의 흡수로 조기에 임플란트 침강과 치근부의 노출을 야기할 수 있다. 그리고 동시에 보철에 의한 구개열의 횡적인 성장방해를 피해야한다. 3) 하악 전방부 : 무치증 아이에서 임플란트의 조기식립이 적응증이 되는 유일한 곳으로 치아가 없을 때는 치조골의 성장이 최소이며 초기에 횡적, 후방 성장이 대부분 완료된다. 그러나 단일 임플란트 식립은 권장되지 않는다. 4)하악후방부: 늦게까지 성장변화가 지속되기 때문에 전후방, 횡적, 수직적 성장의 많은 양이 일어난다. 하악의 회전성장의 영향을 많이 받아 하악 무치악에서 조기 임플란트 사용한 보고도 적고. 자연치아에 인접하여 임플란트를 식립한 기록은 있으나 골격성장이 완료될 때 까지는 식립하지 않는 것이 좋다.

• The korean journal of orthodontics
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• v.41 no.4
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• pp.268-279
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• 2011

Objective: The purpose of this study was to compare self-drilling orthodontic mini-implants of different surfaces, namely, machined (untreated), etched (acid-etched), RBM (treated with resorbable blasting media) and hybrid (RBM + machined), with respect to the following criteria: physical appearance of the surface, measurement of surface roughness, and insertion pattern. Methods: Self-drilling orthodontic mini-implants (Osstem implant, Seoul, Korea) with the abovementioned surfaces were obtained. Surface roughness was measured by using a scanning electron microscope and surface-roughness-testing machine, and torque patterns and vertical loadings were measured during continuous insertion of mini-implants into artificial bone (polyurethane foam) by using a torque tester of the driving-motor type (speed, 12 rpm). Results: The mini-implants with the RBM, hybrid, and acid-etched surfaces had slightly increased maximum insertion torque at the final stage ($p$ < 0.05). Implants with the RBM surface had the highest vertical load for insertion ($p$ < 0.05). Testing for surface roughness revealed that the implants with the RBM and hybrid surfaces had higher Ra values than the others ($p$ < 0.05). Scanning electron microscopy showed that the implants with the RBM surface had the roughest surface. Conclusions: Surface-treated, self-drilling orthodontic mini-implants may be clinically acceptable, if controlled appropriately.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.1
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• pp.1-13
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• 2012

Short implants are used in parts which have anatomical structures like maxillary sinus, inferior alveolar nerve and limited alveolar height due to severe alveolar bone resorption. In these case, there are no need of additional bone augmentation so there are advantages like reduced entire treatment time, reduced patient's discomfort and protection of important anatomical structures. The aim of this study is, in implants whose length is less than 10mm, to analyze the impact of implant length, diameter, location of implant placement, presence of bone graft, presence of prosthesis splinting on survival rates and marginal bone resorption. The samples used in this study were 227 implants, less than 10mm, placed in 137 patients in Wonkwang university dental hospital implant center. From dental charts the information about implant length, diameter, location of implant placement, presence of bone graft, presence of prosthesis splinting were obtained. Emago advanced v5.6(Oral diagnostic systems, Amsterdam, The Netherlands)program was used to measure the amount of marginal bone resorption. Out of total 227 implants, resulting in 96.5 % of survival rate. There was a tendency toward higher failure rates for the maxilla and bone graft site. No significant difference in marginal bone resorption was found associated with length of implants(p>0.05) and neither with the diameter of implants. Among the risk factors examined, more failure rates of short implants can be attributed to poor bone quality in the maxilla and presence of bone graft. At implants under 10mm, length, diameter, location of implant placement, bone graft and splinting of prosthesis didn't affect marginal bone loss.

• The korean journal of orthodontics
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• v.31 no.2 s.85
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• pp.173-185
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• 2001

The orthodontic osseointegrated titanium implant, a kind of intraoral skeletal anchorage can be an alternative to tooth-borne anchorage, in case that the conventional tooth-borne anchorage is not available or the anchorage is critical. This study was conducted to elucidate the effect of early loading on the osseointegration of the orthodontic titanium implant and the healing process of the impaired bone at the site of implant after removing it. In two adult beagle dogs24 osseointegrated titanium implants were inserted into the alveolar bone, with 12 implants placed in each dog. In dog1, 6 out of 12 implants were loaded with 200-300gm of force immediately after placing, and the remaining 6 implants were not loaded for 4weeks. In dog2, all 12 implants had healing period of 4weeks, and then were loaded with 200-300gm of force for another 4weeks. Following an observation period of 4 and 8 weeks, the animals were sacrificed. Then the implants and the surrounding bone of dog1 and dog2 were removed, respectively. Undecalcified sections along the long axis of implant were made and the degree of osseointegration was examined under the light microscope. The results were as follows. 1. In the histologic features of tissues around implants anchored in dog1, there was no difference between immediately loaded implants and unloaded implants. Immature woven bone was ingrowing into the thread spaces from the original compacta and in direct contact with the implant surface in part. 2. The premature loading just after 4weeks healing period did not halt the progress of the osseointegration between bone and implant surface. The woven bone around the implants was maturing into the lamellar bone which resembled the structure of the original compacta at the end of 8weeks observation period. 3. Most implants with the inflammed surrounding mucosa were lost or mobile. The mobile implants were encapsulated by fibrous connective tissue which separated the implant surface from the bone. 4. The impaired bone at the site of the implant failed to anchor was showing recovery without inflammatory reaction 2weeks after removing, with the immaure woven bone lined by active osteoblasts and osteoid. Based on the results of this study, the integration of this orthodontic implant seemed to be impaired by the inflammation of the tissue surrounding the Implant rather than by early loading on implant, and increased with time lapsed after placing the implant. The use of implant described in this report can be recommended as an orthodontic anchorage unit immediately after insertion under the careful control of orthodontic force applied and plaque.

• Journal of Periodontal and Implant Science
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• v.36 no.3
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• pp.601-611
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• 2006

임프란트 식립을 필요로 하는 환자의 수평적 치조제 결손의 증대를 위해 골유도재생술과 병용한 bioactive glass (BG) $(Biogran^{(R)})$ 이식의 골재생 양상을 각기 다른 치유기간을 부여한 4명의 환자에서 평가하였다. 6, 8, 10, 18개월의 치유기간 후 임프란트 식립부위에서 조직절편을 채득하여 골재생을 조직계측학적으로 평가하였다. 임프란트 식립을 위한 surgical reentry시 모든 이식부위는 임상적으로 명확한 수평적 치조제 폭경의 증가를 관찰할 수 있었다. 하지만 조직학적 분석결과 BG는 불량한 골전도성을 나타내었다. 6, 8개월의 치유기간후, 이식부위에서 신생골이 거의 관찰되지 않았으며(2.5%이하), 이식부와 기존 골의 경계부위에서 BG particle에 대한 신생골 성장과 결합양상 또는 관찰할 수 없었다. 10개월의 치유기간후 기존 골조직으로부터 성장한 신생골의 BG particle과의 직접적인 접촉양상을 일부 관찰할 수 있었다. 이식부는 13.2%의 광물화된 신생골조직을 보였고, 대부분의 BG particle은 결체조직으로 둘러싸여 있었다. 18개월의 치유기간이 부여된 환자의 조직절편에서 신생골은 이식부의 10.7%를 차지하여 비교적 낮은 신생골 형성양을 나타내었고, 이식부에 존재하는 잔존BG particle은 대부분은 결체조직으로, 일부분에서 광물화된 골조직으로 둘러싸여 있었다. 6, 8, 10, 18개월에서 잔존 BG particle양은 전체 이식부 면적에 대해서 각기 22.3%, 26.5%, 30.7%, 18.7%로 나타났다. 본 증례보고는 비록 한정적인 4명의 환자에서의 조직계측학적 평가결과이지만, 수평적 치조제 결손의 증대를 위해 골유도재생술과 병용한 bioactive glass이식은 불량한 골전도성으로 인해 효과적인 골재생을 위한 이식재로서는 적절하지 않을 수 있음을 나타낸다.

• Journal of Dental Rehabilitation and Applied Science
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• v.26 no.1
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• pp.59-68
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• 2010

Recently, dental implants extensively inserted on edentulous area show highly clinical success rate. However, clinicians cannot exclude the possibility of failure and it often unexpectively occures. Many possible factors associated with failure of dental implants have been reported but controversy exists over the extent to them. In this study, we collected 212 patients who had been inserted 358 dental implants on mandibular premolar and molar area from 2005 to 2006. The survival rate of fixtures was recorded according to age of patients, implantation site, implant system, diameter and length of fixtures. Multi-variable analysis using SPSS chi-square test was operated to verify relation of each factors and survival rates. Accumulative survival rate was 98.3% for 3 years. Only diameter of fixtures was related to the implant survival rate. This may be thought that wider fixtures had been chosen to rescue implants or used in sites of poor bone quality. Further continuous study will be needed for direct guidance associated with survival rate of implants.