• The Journal of Korean Academy of Prosthodontics
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• v.52 no.4
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• pp.366-375
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• 2014

Surgical guide not only provide diagnosis and treatment plan, but even location and direction of implantation. Surgical guide could be divided into non-limited design, partially limited design, and completely limited design. Partially limited design is easily manufactured and inexpensive but less accuracy, compared to completely limited design. From this approach, partially limited design may be particularly effective in patients who present with a single missing tooth or partially edentulous teeth. Completely limited design is anatomically accuracy, esthetical and functional, optimized treatment for prosthetic and biomechanical perspective, and also minimizes discomfort for post-treatment. The purpose of this study is to review previous studies of various surgical guides and applying in clinic.

• The korean journal of orthodontics
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• v.37 no.2 s.121
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• pp.89-97
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• 2007

Objective: The purpose of this study was to measure the insertion torque of orthodontic miniscrews regarding changes in their shape, diameter, and length. Methods: Torque values were measured during continuous insertion of the miniscrews into solid rigid polyurethane foam, using a torque tester of driving motor type with a regular speed of 3 rpm. Orthodontic miniscrews (Biomaterials Korea, Seoul, Korea) of cylindrical type and taper type were used. Results: Increasing the length and diameter of the miniscrews increased the maximum insertion torque value in both cylindrical and taper type screws. Insertion torque was increased at the incomplete head of the cylindrical type screw, and at the tapered part of the taper type screw. The insertion torque value of miniscrews was influenced most by diameter, then shape and length. As a result, it was shown that the diameter of the screw had the most influence on insertion torque, and the taper type screw had a higher torque value than the cylindrical type screw. Conclusion: Therefore, a large diameter or taper type screw are adequate for areas of thin cortical bone with a large interdental space, and a small diameter or cylindrical type screw are adequate in the mandibular molar area or the midpalatal area having thick cortical bone.

• The korean journal of orthodontics
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• v.38 no.4
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• pp.228-239
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• 2008

Objective: The aim of this study was to evaluate the strain induced in the cortical bone surrounding an orthodontic microimplant during insertion. Methods: A 3D finite element method was used to model the insertion of a microimplant (AbsoAnchor SH1312-7, Dentos Co., Daegu, Korea) Into 1 mm thick cortical bone with a pre-drilled hole of 0.9 mm in diameter. A total of 1,800 analysis steps was used to simulate 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, was observed in the bone along the whole length of the microimplant. At the bone in the vicinity of the screw tip, strains of higher than 100% was recorded. The insertion torque was calculated at approximately 1.2 Ncm which was slightly lower than those measured from the animal experiment using rabbit tibias. Conclusions: The insertion process of a microimplant was successfully simulated using the 3D finite element method which showed that bone strains from a microimplant insertion might have a negative impact on physiological remodeling of bone.

• Journal of Periodontal and Implant Science
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• v.27 no.1
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• pp.91-109
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• 1997

본 연구에서는 악골에 식립된 순수한 타이타늄 임프란트와 타이타늄 플라즈마 처리된 타이타 늄 임프란트 및 수산화인회석으로 피막처리된 타이타늄 임프란트의 주위 골조직을 광학현미경 과 주사전자현미경을 이용하여 비교 관찾히였다. 3 마리의 beagle dog 에서 상하악 소구치를 편측으로 발거한 후 12 주의 치유기를 거쳐 임프란트 를 식립하였으며, 임프란트 식립 후 4주, 8주 및 12주에 실험동물을 각각 희생시켜서 조직 표본을 제작하였다. 임프란트 주위의 골조직에서 염증이나 이물반응은 관찰되지 않았으며, 정상적인 악골에서와 유사한 골조직 소견이 관찰되었다 상악골 및 하악골에 식립된 모든 임프란트의 4주 표본에서, 골과 임프란트 변의 직접적인 접촉이 관찰되었다. 동일한 치유기에서는, 상악골에 식립된 임프란트의 면에 비하여 하악골에 식립된 동종의 임프란트의 변에서 더 많은 양의 골접촉이 관찰되었으며, 순수한 타이타늄 임프란트의 면에 비하여 피막처리된 타이따늄 임프란트의 변에서 더 많은 양의 골접촉이 관찰되었다.

• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.2
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• pp.203-211
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• 2008

Minimizing damage to anatomical structure is a prerequisite for skeletal anchorage system to install a miniscrew. This research has focused on evaluating the stability and safety of installation in the maxillary molar buccal area, in which most miniscrews are installed clinically and initial fixation is weak. CT (computerized tomography)images were taken for surveying the possibility of damaging to adjucent teeth in accordance with installation angle. If we install a mini-screw($1.2{\times}6.0mm$) in the maxillary molar buccal area, it would be located generally in the 5~8mm upper of CEJ and 3~5mm inner of the cortical bone surface. We has measured the space between roots And comparison has been made for gender and the space between roots in accordance with the 3 different angles of installation(30 degree, 40 degree, 60 degree) in 3 categories. Category 1 : between 1st molar and 2nd molar Category 2 : between 1st molar and 2nd premolar Category 3 : between 1st premolar and 2nd premolar The result are as follow; 1. The space for category 1 was significantly small. 2. For the installation angle, it was safer to install with steeper angle in category 1 and category 2, but not in category 3. According to these results, the installation a miniscrew in category 2, 3 is safer than in category 1. And it is safer to install with steeper angle in category 1 and category 2.

• The korean journal of orthodontics
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• v.38 no.1
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• pp.5-12
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• 2008

Objective: This study was designed to analyze the primary and secondary stability characteristics of orthodontic mini-screws of tapered design when compared with the cylinder mini-screw. Methods: A total of 48 mini-screws were placed into the buccal alveolar bone of the mandible in 6 male beagle dogs. Comparison was made between tapered and cylinder type mini-screws (Biomaterials Korea, Seoul, Korea). Maximum insertion torque (MIT) was measured using a torque sensor (Mark-10, MGT 50, USA) during installation, and maximum removal torque (MRT) was recorded after 3 and 12 weeks of loading. Results: Taper mini-screws showed a higher MIT value of 22.3 Ncm compared with cylinder mini-screw showing 13.6 Ncm (p < 0.001). The MRT of the taper mini-screw showed a significantly higher value of 9.1 Ncm than those of cylinder mini-screw of 5.7 Ncm at 3-weeks after installation (p < 0.05). However, there was no difference in the MRT value between the taper and cylinder mini-screws at 12 weeks of loading. Conclusions: These results showed that the high insertion torque of the taper mini-screw design increases initial stability until 3 weeks of loading, but does not have any effect on the secondary stability at 12 weeks of loading.

• 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.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.18 no.1
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• pp.27-32
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• 2009

오늘날 단일치 임플란트의 식립은 현재 시행되고 있는 가장 일반적인 임플란트 술식 중 하나이며, 상악 전치부는 이중 가장 흔하게 시행되는 식립 부위 중하나이다. 그럼에도 불구하고 상악 전치부 단일 상실치에 대한 치료 계획은 구강 내 다른 어떤 부위보다 복잡하며 고도로 심미성을 요구하는 부위로서 아무리 경험이 많고 기술이 뛰어난 치과의사라 할지라도 시술할 때마다 큰 도전으로 여겨지는 경우가 대부분일 것이다. 상악 전치부에서 임플란트 보철의 심미적 성공을 이루기 위해서는 모든 구성 요소 하나하나에서 심미적 결과를 이룩하여야 하고 이 결과들이 완벽하게 조화를 이루게 하여야 하며 이는 결코 쉬운 일이 아닐 것이다. 시술 시 교과서의 그림처럼, 모형에 식립해 본 것처럼 쉽게 되지 않는 것은 물론 구강 내 환경이 모형과 다를 리 만무한 것이 당연한 첫 번째 이유이며 뿐만 아니라 환자 대부분의 경우 모형처럼 완벽한 경 연조직이 갖추어진 상태에서 치아만 상실된 경우는 거의 찾아볼 수 없기 때문인 이유도 크다. 즉, 원하는 위치에 식립을 하고 장기간의 심미적 유지를 위해서는 경 연조직에 대한 처치가 필수적인 경우가 대부분이라는 이야기이다. 이를 간과하고 식립한 경우 추후 심각한 bone의 resorption, 그에 따르는 gingiva의 끔찍한 recession, 용납할 수 없는 비심미적 보철물의 제작은 불을 보듯 뻔한 결과가 될 것이다. 따라서 상악 전치부 식립 치료계획 시 치과의사는 성공적 결과에 영향을 미칠 수 있는 모든 요소에 촉각을 곤두세우고 이들의 완벽한 처치에 최선을 다 해야할 것이다.

• The Journal of Korean Academy of Prosthodontics
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• v.52 no.4
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• pp.279-286
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• 2014

Purpose: The aim of this study was to investigate the effect of implant thread profile on the marginal bone stresses which develop during implant insertion. Materials and methods: Four experimental implants were created by placing four different thread systems on the body ($4.1mm{\times}10mm$) of the ITI standard implant. The thread types studied in this study included the buttress, v-shape, reverse buttress, and square shape threads. In order to examine the insertion stress generation, 3D dynamic finite element analysis was performed which simulated the insertion process of implants into a 1.2 mm thick cortical bone plate (containing 3.5 mm pilot hole) using a PC-based DEFORM 3D (ver 6.1, SFTC, Columbus, OH, USA) program. Results: Insertion stresses higher than human cortical bone developed around the implants. The level of insertion stresses was much different depending on the thread. Stress level was lowest near the v-shape thread, and highest near the square shaped thread. Difference in the interfacial bone stress level was more noticeable near the valley than the tip of the threads. Conclusion: Among the four threads, the v-shape thread was turned out to minimize the insertion stress level and thereby create better conditions for implant osseointegration.

• 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.