• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제43권4호
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• pp.276-281
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• 2017

This case series study demonstrates the possibility of successful implant rehabilitation without bone augmentation in the atrophic posterior maxilla with cystic lesion in the sinus. Sinus lift without bone graft using the lateral approach was performed. In one patient, the cyst was aspirated and simultaneous implantation under local anesthesia was performed, whereas the other cyst was removed under general anesthesia, and the sinus membrane was elevated in a second process, followed by implantation. In both cases, tapered 11.5-mm-long implants were utilized. With all of the implants, good stability and appropriate bone height were achieved. The mean bone level gain was 5.73 mm; adequate bone augmentation around the implants was shown, the sinus floor was moved apically, and the cyst was no longer radiologically detected. Completion of all of the treatments required an average of 12.5 months. The present study showed that sufficient bone formation and stable implantation in a maxilla of insufficient bone volume are possible through sinus lift without bone materials. The results serve to demonstrate, moreover, that surgical treatment of mucous retention cyst can facilitate rehabilitation. These techniques can reduce the risk of complications related to bone grafts, save money, and successfully treat antral cyst.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제39권6호
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• pp.269-273
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• 2013

Objectives: This study is designed to evaluate the mechanical stability of orthodontic mini-implants with vertical grooves in rabbits. Materials and Methods: This study was done from March 2011 to February 2012 in Dental Research Institute of Seoul National University. Thirty-two mini-implants in the control group and 32 in the rotation bump (RB) group were inserted in the tibias of 16 rabbits and were removed after two weeks and four weeks, respectively. The maximum insertion torque (MIT), maximum removal torque (MRT), torque ratio (TR) of MRT to MIT and removal angular momentum (RAM) were all measured at the time of removal. Results: There were no significant differences between the two groups in MIT and MRT at two weeks or four weeks. However, TR and RAM at four weeks in the RB group were significantly higher than in the control group (P<0.05). TR of the RB group was significantly increased at four weeks (P<0.05). In both groups, RAM at four weeks was significantly higher than at two weeks (P<0.05). Conclusion: These results suggest that RB of the mini-implant could provide resistance to the removal rotation, although it did not increase the MRT.

• 대한치과보철학회지
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• 제53권4호
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• pp.352-358
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• 2015

파킨슨 병을 가지고 있는 환자의 총의치는 혀와 입술의 불수의적 운동으로 인해 유지와 안정이 좋지 않은 경우가 많다. 또한 제한된 수의 운동으로 인해 피개의치의 장착에 어려움이 어려울 수 있다. 본 증례는 파킨슨병을 가진 상, 하악 부분 무치악 환자에서 상악에서는 잔존치근을 이용한 magnetic attachment와 하악에서는 2개의 임플란트를 이용한 $Locator^{(R)}$ attachment를 통해 유지와 안정을 증진시킨 피개의치 수복증례로서, 기능적으로 개선된 보철물을 제작했기에 보고하는 바이다.

• The Journal of Advanced Prosthodontics
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• 제11권6호
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• pp.305-312
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• 2019

PURPOSE. The purpose of this study was to compare computer-aided design/computer-aided manufacturing (CAD/CAM) abutment and prefabricated abutment in Morse taper internal connection type implants after cyclic loading. MATERIALS AND METHODS. The study was conducted with internal type implants of two different manufacturers (Group Os, De). Fourteen assemblies were prepared for each manufacturer group and divided into 2 groups (n=7): prefabricated abutments (Os-P, De-P) and CAD/CAM abutments (Os-C, De-C). The amount of axial displacement and the removal torque values (RTVs) were measured before and after cyclic loading (10⁶ cycles, 3 Hz with 150 N), and the tensile removal force to dislodge the abutments was measured after cyclic loading. A repeated measures ANOVA and a pattern analysis based on the logarithmic regression model were conducted to evaluate the effect of cyclic loading on the axial displacement. The Wilcoxon signed-rank test and the Mann-Whitney test was conducted for comparison of RTV reduction% and tensile removal forces. RESULTS. There was no significant difference between CAD/CAM abutments and prefabricated abutments in axial displacement and tensile removal force; however, significantly greater RTV reduction% after cyclic loading was observed in CAD/CAM abutments. The correlation among the axial displacement, the RTV, and the tensile removal force was not significant. CONCLUSION. The use of CAD/CAM abutment did not significantly affect the amount of axial displacement and tensile removal force, but presented a significantly greater removal torque reduction% than prefabricated abutments. The connection stability due to the friction at the abutment-implant interface of CAD/CAM abutments may not be different from prefabricated abutment.

• Journal of Periodontal and Implant Science
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• 제39권4호
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• pp.431-435
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• 2009

Purpose: The purpose of this study is to evaluate the long term clinical and radiographic outcome and stability after transplantation of third molar with complete root formation. Methods: The subjects were 31 teeth (male 17, female 14, aged 22-55, average 39.9 yr old) of 31 patients who visited the department of periodontics and passed more than two years after autotransplantation procedure and still under regular check up. Modified success criteria of Chamberlin and Goerig was applied to determine the success of autotransplantation. Results: Three out of 31 teeth failed and resulted 90.3% of success rate. When compared according to sex, 15 out of 17 teeth had succeeded in male, 13 out of 14 succeeded in female. When compared the success rate according to cause of extraction, tooth loss due to caries and root fracture had all succeeded but 3 out of 24 had failed in tooth loss due to periodontal disease. When compared according to donor teeth, 12 out of 14 maxillary third molars and 16 out of 17 mandibular third molars had succeeded. Conclusions: In long term evaluation over two years, if appropriate surgical procedure and proper case selection is made, autotransplantation of the third molar with complete root formation can be the alternative choice that substitutes prosthetic or implant treatment and it is a functionally acceptable procedure.

• 대한치과교정학회지
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• 제51권4호
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• pp.260-269
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• 2021

Objective: To identify the most favorable sites that optimize the initial stability and survival rate of orthodontic mini-implants, this study measured hard and soft tissue thicknesses in the median and paramedian regions of the palate using cone-beam computed tomography (CBCT) and determined possible sex- and age-related differences in these thicknesses. Methods: The study sample comprised CBCT images of 189 healthy subjects. The sample was divided into four groups according to age. A grid area was set for the measurement of hard and soft tissue thicknesses in the palate. Vertical lines were marked at intervals of 0, 1.5, and 3.0 mm lateral to the midpalatal suture, while horizontal lines were marked at 2-mm intervals up to 24 mm from the posterior margin of the incisive foramen. Measurements were made at 65 points of intersection between the horizontal and vertical lines. Results: The palatal hard tissue thickness decreased from the anterior to the posterior region, with a decrease in the medial-to-lateral direction in the middle and posterior regions. While the soft tissue was rather thick around the lateral aspects of the palatal arch, it formed a constant layer that was only 1-2-mm thick throughout the palate. Statistically significant differences were observed according to sex and age. Conclusions: The anterolateral palate as well as the midpalatal suture seem to be the most favorable sites for insertion of orthodontic mini-implants. The thickness of the palate differed by age and sex; these differences should be considered while planning the placement of orthodontic mini-implants.

• 대한치과보철학회지
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• 제48권2호
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• pp.128-134
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• 2010

연구목적: 본 연구에서는 건강기능식품인 $PostPlant^{TM}$ Calcium을 임플란트 식립 환자에게 투여하고, 투여하지 않은 군과 비교하여 그 유효성과 안정성을 평가하여 투여 후 골밀도의 변화 및 골유착 기간의 단축 여부를 평가하고자 하였다. 연구 재료 및 방법 임플란트 식립 후에Post$PostPlant^{TM}$ Calcium을 투여한 실험군은 18명의 환자를 대상으로 25개의 임플란트를 식립하였고, 투여하지 않은 대조군에서는 7명의 환자에게 9개의 임플란트를 식립하여 관찰하였다. 일차수술 후, 이차수술 후, 6개월 후에 $Osstell^{TM}$ Mentor, $Periotest^{(R)}$를 이용하여 임플란트 안정성을 비교 분석하였고, 일차수술후, 1, 3, 6개월 후에 방사선 사진 촬영을 시행하여 임플란트 주위 골밀도를 측정하여 비교 분석하였다. 결과:1. $Osstell^{TM}$ Mentor의해 측정된 ISQ 값은 측정 결과 시간이 경과함에 따라 실험군, 대조군 모두 수치가 높아지는 경향을 보였다. 실험군의 측정값이 대조군에 비해 더 높은 수치를 보였으며, 식립 6개월 후에 실험군과 대조군 간에 통계적으로 유의한 차이가 관찰되었다 (P< .05); 2. $Periotest^{(R)}$ 측정 결과 시간이 경과함에 따라 실험군, 대조군 모두 수치가 낮아지는 경향을 보였으며, 실험군이 대조군에 비해 더 낮은 수치를 나타내었으나 각 군간에 통계적인 유의성은 없었다. 3. 골밀도 측정 결과 시간이 경과함에 따라 실험군, 대조군 모두 골밀도 수치가 증가하는 경향을 보였으며, 실험군이 대조군에 비해 더 높은 수치를 나타내었으나 각 군간에 통계적인 유의성은 없었다. 결론:임상적으로 임플란트 식립 후 환자가 $PostPlant^{TM}$ Calcium을 장기간 복용하는 것이 임플란트 안정성을 높이고, 골유착을 성공적으로 이루는데 도움을 줄 수 있다고 사료된다.

• 대한치과보철학회지
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• 제46권6호
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• pp.561-568
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• 2008

STATEMENT OF PROBLEM: Currently, many implant systems are developed and divided into two types according to their joint connection: external or internal connection. Regardless of the connection type, screw loosening is the biggest problem in implant-supported restoration. PURPOSE: The purpose of this study is to assess the difference in stability of abutment screws between the external and internal hexagonal connection types under cyclic loading. MATERIAL AND METHODS: Each of the 15 samples of external implants and internal abutments were tightened to 30 N/cm with a digital torque gauge, and cemented with a hemispherical metal cap. Each unit was then mounted in a $30^{\circ}$ inclined jig. Then each group was divided into 2 sub-groups based on different periods of cyclic loading with the loading machine (30 N/ cm - 300 N/cm,14 Hz: first group $1{\times}10^6$, $5{\times}10^6$ cyclic loading; second group $3{\times}10^6$, $3{\times}10^6$ for a total cyclic loading of $6{\times}10^6$) The removal torque value of the screw before and after cyclic loading was checked. SPSS statistical software for Windows was used for statistical analysis. Group means were calculated and compared by ANOVA, independent t-test, and paired t-test with ${\alpha}$=0.05. RESULTS: In the external hexagonal connection, the difference between the removal torque value of the abutment screw before loading, the value after $1{\tims}10^6$ cyclic loading, and the value after $1{\times}10^6$, and additional $5{\times}10^6$ cyclic loading was not significant. The difference between the removal torque value after $3{\times}10^6$ cyclic loading and after $3{\times}10^6$, and additional $3{\times}10^6$ cyclic loading was not significant. In the internal hexagonal connection, the difference between the removal torque value before loading and the value after $1{\times}10^6$ cyclic loading was not significant, but the value after $1{\times}10^6$, and additional $5{\times}10^6$ cyclic loading was reduced and the difference was significant (P < .05). In addition, in the internal hexagonal connection, the difference between the removal torque value after $3{\times}10^6$ cyclic loading and the value after $3{\times}10^6$, and additional $3{\times}10^6$ cyclic loading was not significant. CONCLUSION: The external hexagonal connection was more stable than the internal hexagonal connection after $1{\times}10^6$, and additional $5{\times}10^6$ cyclic loading (t = 10.834, P < .001). There was no significant difference between the two systems after $3{\times}10^6$, and additional $3{\times}10^6$ cycles.

• 구강회복응용과학지
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• 제26권2호
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• pp.97-109
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• 2010

연구목적 : 본 연구는 임플랜트 지대주에 동적하중을 가하기 전, 후의 풀림토크 변화를 측정함으로써 수종의 지대주에 가해진 단기간의 교합력이 임플랜트-지대주의 안정성에 영향을 미치는지를 연구하고자 하였다. 재료및 방법 : 임플랜트 고정체는 외부육각구조를 사용하였고, 티타늄합금 지대주, 지르코니아 지대주, 주조 금합금 지대주인 UCLA plastic abutment를 사용하였다. 초기 풀림회전력을 측정하고, 하중을 $10^5$ 회 가한후, 풀림회전력을 측정하였다. 초기 풀림회전력 상실률, 하중후 풀림회전력 상실률, 동적하중에 의한 풀림회전력 상실률을 계산하였다. 결과 : 초기 풀림회전력, 동적 하중후 풀림회전력, 초기 풀림회전력 상실률, 동적 하중후 풀림회전력 상실률, 동적 하중에 의한 풀림회전력 상실률은 각 지대주간 유의한 차이를 나타내지 않았다. 또한, 각 지대주 내에서 동적 하중 전후의 풀림회전력은 통계적으로 유의한 차이를 나타내지 않았다. 결론 : Titanium, zirconia, UCLA 지대주의 초기 나사풀림은 지대주간 유의한 차이가 없음을 알 수 있었고, 초기의 저작력은 하중전후 나사풀림에 큰 영향을 주지 않는다고 생각된다. 또한, UCLA, zirconia, titanium 지대주의 선택시 초기 나사풀림과 관련하여 특정 종류의 지대주 선택을 기피할 필요는 없다고 생각된다.

• 대한치과보철학회지
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• 제48권1호
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• pp.61-68
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• 2010

연구 목적: 임플란트 보철물의 유지 나사에 적용되는 전하중은 나사를 조임으로써 임플란트와 지대주 사이에 인장력이 발생하면서 나사가 신장되는 힘을 말한다. 이 연구는 전하중에 영향을 미치는 생역학적 요인들과 나사 풀림에 기여하는 다양한 요인에 대하여 문헌을 고찰하고자 하였다. 연구 재료 및 방법: 1981년부터 2009년까지 발표된 나사 풀림을 다룬 임상연구 중 설정한 기준에 합당한 문헌을 요약하여 나사 풀림의 빈도를 밝혔고 나사의 안정성과 전하중에 관한 생역학을 다룬 문헌을 조사하고 요약하였다. 또한, 본 교실에서 연구한 실험실적 결과도 포함시켰다. 결과 및 결론: 나사 풀림의 정도는 나사에 토크를 가하는 기술이 발달함에 따라 현저히 감소하고 있다. 그 외에도 나사의 재질, 마찰계수를 감소시키기 위한 피복 기술의 발달 및 나사산의 모양 등 전하중에 영향을 줄 수 있는 요인을 고찰하였다. 전하중이 일정 수준 이하로 떨어지게 되면 나사의 움직임이 발생하게 되는데 이는 장기적으로 축적되어 피로파절 및 응착 마모, 소성 변형 등을 유발하게 되므로 주의해야 한다. 최적의 전하중을 주기 위해서는 토크 렌치를 이용하고 환자의 재내원시 다시 토크를 가하는 방법 등이 추천된다.