• 대한치과보철학회지
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• 제43권1호
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• pp.120-131
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• 2005

Statement of problem. More than 70% of patients who need the implant supported restoration are parially edentulous. The principles of design for implant supported fixed partial denture in mandibular posterior region are many and varied. Jurisdiction for their use is usually based on clinical evaluation. There are several areas or interest regarding the design of implant supported fixed partial denture in mandibular posterior region. 1) Straight and tripod configuration in implant placement, 2) Two restoration types such as individualized and splinted restorations. Purpose. The purpose of this study was to compare the amount and distribution of stress around the implant fixtures placed in the mandibular posterior region with two different arrangements and to evaluate the effects of splinting using the photoelastic stress analysis. Material & methods. 1) Production of study model: Mandibular partially edentulous model was waxed-up and duplicated with silicone and two models were poured in stone. 2) Fixture installation and photoelastic model construction: Using surveyor(Ney, USh), 3 fixtures(two 4.0 $\times$13 mm, one 5.0$\times$10 mm, Lifecore, USA) were insta)led in straight & tripod configurations. Silicone molds were made and poured in photoelastic resin (PL-2. Measurements group, USA). 3) Prostheses construction: Four 3-unit bridges (Type III gold alloy, Dongmyung co., Korea) were produced with nonhexed and hexed UCLA abutments and fitted with conventional methods. The abutments were tightened with 30 Ncm torque and the static loads were applied at 12 points of the occlusal surface. 4) Photoelastic stress analysis : The polarizer analyzer system with digital camera(S-2 Pro, Fujifilm, Japan) was used to take the photoelastic fringes and analysed using computer analysis program. Results. Solitary hexed UCLA restoration developed different stress patterns between two implant arrangement configurations, but there were no stress transfer to adjacent implants from the loaded implant in both configurations. However splinted restorations showed lesser amount of stresses in the loaded implants and showed stress transfer to adjacent implants in both configurations. Solitary hexed UCLA restoration with tripod configuration developed higher stresses in anterior and middle implants under loading than implants with straight configurations. Splintied 3 unit fixed partial dentures with tripod configuration showed higher stress development in posterior implant under loading but there were no obvious differences between two configurations. Conclusions. The tripod configuration of implant arrangement didn't show any advantages over the straight configuration. Splinting of 3 unit bridges with nonhexed UCLA abutments showed less stress development around the fixtures. Solitary hexed UCLA restoration developed tilting of implant fixture under offset loads.

• Journal of Periodontal and Implant Science
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• 제37권4호
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• pp.705-718
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• 2007

The purpose of this study was to evaluate 6 years cumulative survival rate (CSR, %) of mandibular posterior single tooth implants replaced with $Br{\aa}nemark$ $TiUnite^{(R)}$ implant system. The findings from this study were as followed ; 1. The 112 (111 persons) single implants that were placed in the mandibular posterior region were successful except 4 cases and showed 96.42% CSR. 2. The 55 (55 persons) single implants that were placed in the mandibular first molar region were successful except 2 cases and showed 96.36% survival rate. And, among the 57 (56 persons) single implants replacing the mandibular second molar. 2. failed showing 96.49% survival rate. There was no significant statistical difference. 3. Among the total 112 implants, 5.0mm wide diameter implants were placed in 96 cases(85.7%) showing 96.9% survival rate. 4.0mm standard diameter implants were placed in 16 cases showing 93.8% survival rate. There was no significant statistical difference. 4. Long implants above 10.0mm length were placed 103 cases(91.0%) and showed 96.1% survival rate. Short implants within 8.5mm length were placed 9 cases and showed 100% survival rate. There was no significant statistical difference. 5. 37 implants placed in type I, II bone quality were showed higher survival rate(100%) than that of 52 implants placed in type III, IV bone quality(92.3%). But, there was no significant statistical difference. In conclusion, $Br{\aa}nemark$ $TiUnite^{(R)}$ implant showed successful results when replacing manbibular single molar.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제35권3호
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• pp.170-175
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• 2009

Purpose : The purpose of this study is to evaluate 7-year survival rate of implants placed without bone graft in posterior maxilla and compare the survival rate by the age and gender of patient, length and diameter of implant, region of implant placement, bicortical engagement of fixture, and connection of prosthesis. Material and methods : 78 patients (170 implants) who visited our institution from 2002 to 2007 and were followed up with panoramic view and medical records. Kaplan-Meier survival analysis and Log Rank (Mantel-Cox) test were used. Results and conclusions : A 7-year cumulative survival rate for implants placed in posterior maxilla without sinus graft was 95.3%. The survival rate in men was 91.8%, significantly lower than 98.8% in woman.(p<0.05). However, the survival rate by the length of the implants did not show any significant differences.(p>0.05), while the wide platform implant resulted in 85% survival rate which was statistically lower than 98.5% in regular platform. The posterior maxillary implants engaged bicortically showed 97.6% of 7-year Survival rate, comparing 88.6% in not engaged implants. The survival rate of the single implant was 91.2%, while 98.5% in splinted prosthesis. Therefore, the bicortical engagement of the fixtures and splinted prosthesis may be recommended to get a long-term survival rate in posterior maxilla.

• 구강회복응용과학지
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• 제30권4호
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• pp.278-288
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• 2014

목적: 이 연구의 목적은 상악 및 하악의 완전 무치악 및 부분 무치악 부위에 식립된 골유착성 임플란트의 보철 전 초기 생존율 및 생존과 관련된 요소를 평가하고 실패를 야기하는 요인에 대해 알아보는 것이다. 연구 재료 및 방법: 2004년부터 2013년까지 770명의 환자에서 총 2158개의 골내 임플란트를 식립하였다. 임플란트의 소실과 환자의 연령 및 성별, 식립 위치, 임플란트 시스템, 길이 및 직경, 그리고 골이식 방법과의 연관성을 평가하기 위해 임상적 비교를 시행하였다. 결과: 임플란트 식립 위치에 따라 상악 전치부에서 98.23%, 상악 구치부 96.97%, 하악 전치부 97.85%, 하악 구치부 98.75%의 임플란트 생존율을 보였다(P < 0.05). 임플란트의 종류 및 표면처리 기법은 임플란트 생존율과 특이성을 보이지 않았다. 임플란트 매식체의 직경에 따라 3.0 mm 이하의 임플란트에서 100%, 3.0 - 3.5 mm 97.09%, 3.5 - 4.0 mm 98.19%, 4.0 - 4.5 mm 98.29%의 생존율을 보였고, 5.0 mm 이상의 직경을 가진 넓은 폭경의 임플란트에서 75%의 비교적 낮은 생존율을 보였다(P < 0.05). 임플란트 매식체의 길이에 따라 9 - 11 mm 및 11 - 13 mm의 길이를 가진 임플란트에서 각각 98.12% 및 98.17%의 높은 생존율을 보였으나 통계학적 유의성을 가지진 못하였다. 골이식술의 방법에 따라 상악동 골이식술을 단독으로 시행한 부위에서 임플란트 생존율은 89.05%, 골유도 재생술을 단독으로 시행한 경우 98.28%, 상악동 골이식술과 골유도 재생술을 동시에 시행한 경우 98.34%, 골이식술이 동반되지 않은 경우 99.28%의 생존율을 보였다(P < 0.05). 결론: 이번 연구에서 임플란트 식립 후 최종 보철물 시적 전 초기단계에서의 임플란트 생존율은 임플란트의 식립위치, 임플란트 매식체의 직경, 그리고 골이식 방법과 관련이 있었다. 이러한 결과에 따라 각각 상악 구치부, 5.0 mm 이상의 넓은 임플란트, 그리고 상악동 골이식술을 단독으로 시행한 부위에서 현저하게 낮은 생존율을 확인할 수 있었다.

• 대한치과보철학회지
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• 제47권3호
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• pp.335-341
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• 2009

연구목적: 충분한 골질과 골량은 임플란트의 조기 실패 방지와 초기 안정성을 위해서 중요한 사항으로 알려져 있다. 임플란트 길이나 직경이 초기 안정성에 미치는 영향을 연구한 다수의 실험들이 골과의 접촉면적을 달리하였기 때문에 직경과 길이만이 초기 안정성에 미치는 실제 영향을 파악하는데 한계가 있다. 이에 유사한 표면적을 가지는 임플란트를 통하여 길이와 직경 상대적 변화가 초기 안정성에 미치는 영향을 알아보고자 하였다. 연구 재료 및 방법: 골질에 따라 피질골과 해면골의 두께가 다른 4종류의 폴리우레탄 모형골을 임플란트 식립에 사용하였다. 유사한 표면적과 형태를 가지나 직경과 길이가 서로 다른 임플란트 ($3.5{\times}13.0\;mm$, $4.0{\times}11.5\;mm$, $4.5{\times}10.0\;mm$, $5.0{\times}8.5\;mm$) 10개를 식립하고 식립 회전력과 공진 주파수를 측정하였다. 결과 및 결론: 초기 안정성에 영향을 미치는 주 요소는 골질이었으며 (P < .05), 식립 회전력과 공진 주파수 모두 골질이 우수할수록 높은 측정치를 보였다. 2. D1, D2, D3 모형골에서 임플란트의 직경이 커지고 길이가 짧아짐에 따라 공진 주파수는 유의한 차이를 보이지 않았으나 (P >.05), 식립 회전력은 증가하였다 (P <.05). 3. D4 모형골에서는 임플란트의 직경이 커지고 길이가 짧아짐에 따라 공진주파수와 식립 회전력 모두 감소하였다 (P <.05). 이상의 결과로부터 골질이 양호한 조건에서는 길이가 짧더라도 직경이 큰 임플란트의 사용이 초기 안정성 측면에서 부가적 수술의 대안이 될 수 있을 것으로 생각된다.

• Journal of Periodontal and Implant Science
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• 제36권3호
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• pp.661-671
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• 2006

The purpose of this study was to evaluate cumulative survival rate (CSR, %) of mandibular posterior single tooth implants replaced with ITI SLA (sand-blasted, large-grit, acid-etched) implant system and compare the CSR between first and second molar. The findings from the results were as follows; 1. Total of 158 implants were inserted into 147 patients. 68 patients were males, 79 patients were females and their mean age was 47.8 years. 98 implants were placed in first molar area and 60 implants were placed in second molar area. In terms of diameter, implants with wide diameter over 4.8mm dominated (91.1%). Implants with length over lOmm were used (96.2%). 2, In the two cases, there was a slight transient numbness which recovered within 1-2 months. Nine SynOcta screw type abutments demonstrated screw loosening, There were ten cases of crown fallen-out from decementation. 3. Only one failed out of 158 implants. The CSR was 99.4%. The CSRs for first molar and second molar were 99% and 100%, respectively. From the results, it was concluded that single tooth replacement implant in the mandibular posterior area, might be considered as the effective treatment modality comparable to the conventional crown and bridge.

• 구강회복응용과학지
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• 제31권4호
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• pp.364-370
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• 2015

최근 구치부 부분 무치악 환자의 임플란트 보철 수복은 기능적뿐만 아니라 심미적으로도 환자의 만족을 이끌어내야 하는 과제를 안고 있다. 이렇게 환자의 요구가 높아지면서 상실된 자연치아와 유사한 형태의 임플란트 보철을 사용한 구강회복이 보철수복의 중요한 이슈가 되고 있다. 이를 위해서는 기성 지대주 보다는 더 넓은 customized CAD/CAM 지대주를 사용함으로써 자연스러운 출현윤곽을 재현할 수 있다. 넓은 지대주를 지지해주기 위해서는 충분한 폭과 높이를 가지는 각화치은이 존재해야 하는데, 만약 긴 치아상실기간이나 골이식술 등으로 인해 임플란트 주위에 각화치은이 부족한 경우에는 연조직 증대술을 시행하는 것이 추천된다. 이러한 과정을 통해 심미적이고 기능적인 임플란트 보철 제작이 가능하며 구강위생관리를 용이하게 하고 향후 임플란트 주위염의 발생 가능성을 감소시킨다. 본 증례는 구치부 부분 무치악 환자에서 골이식술, 상악동 이식술, 임플란트 식립술 및 연조직 이식술을 사용하여 부족한 치조골과 각화치은 및 협측전정을 회복하였으며, customized CAD/CAM 지대주와 지르코니아 보철물을 이용하여 수복한 증례로 주기적인 내원 및 검사를 통해 기능적, 심미적으로 만족할만한 결과를 얻었기에 이 사례를 보고하고자 한다.

• Journal of Periodontal and Implant Science
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• 제38권2호
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• pp.135-142
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• 2008

Purpose: Numerous studies have shown that crestal bone resorption around the implant was related to the location of the implant abutment junction(IAJ). Recently it was hypothesized that platform switching termed the inward horizontal repositioning of the IAJ might limit bone resorption around the implants. The purpose of this clinical study was to evaluate the effect of platform switching on crestal bone resorption. Materials and Methods: The crestal bone loss of 65 external hex implants in 26 patients were radiographically measured at crown placement and follow-up examinations. 23 standard implants(non-platform switching group, NP) were connected with the matching abutments and 42 wide implants(platform switching group, PS) were connected with the 1 mm smaller diameter abutments. Results: There was significant difference of crestal bone loss between NP group and PS group. For implants in the NP group, mean crestal bone loss was $1.18{\pm}0.68\;mm$ at crown placement and $1.42{\pm}0.41\;mm$ at follow-up. The meal bone loss in PS group was $0.47{\pm}0.52\;mm$ at crown placement and $0.60{\pm}0.65\;mm$ at follow-up. When the crestal bone changes according to placement depths of implants were compared, subcrestal position of IAJ had a significantly less bone loss in PS group, but it was not in NP group. Conclusion: Within the limits of the present study, it was concluded that platform switching technique might decrease crestal bone loss around the implants. Additionally, when the IAJ of implant was placed 1 mm deeper in the alveolar bone, the effect of platform switching on bone loss was enhanced.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제30권3호
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• pp.175-180
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• 2004

In this study, three treatment options to replace two posterior missing teeth were investigated using three dimensional finite element analysis: two wide(${\phi}5.0mm$) implants(the experimental model I), two standard(${\phi}3.75mm$) implants(the experimental model II), and three standard(${\phi}3.75mm$) implants(the experimental model III). Two kinds of load case were applied ; 1) perpendicular on occlusal surface(axial load), parallel on occlusal surface(lateral load). 2) perpendicular on occlusal surface(3mm lateral to central point). The results obtained from this study were as follows; value of Von-mises stress (equivalent stress) was smallest in the two wide implant among the three experimental models. It was reported that the diameter is the efficient factor than osseointegrated surface area.

• Journal of Periodontal and Implant Science
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• 제36권2호
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• pp.461-471
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• 2006

In order to achieve a satisfactory esthetic result of periodontal surgery or implant in maxillary anterior area, periodontists must be aware of normal alveolar bone anatomy. The purpose of this study was to evaluate the relationship of alveolar bone morphology to tooth shape and form. 78(mean age : 25 yrs) periodontally healthy volunteers participated in this study. Two maxillary central incisor and one lateral incisor were selected to study. With minimal local anesthesia, gutta-percha cone inserted to labial gingival sulcus of selected teeth just after bone sounding with periodontal probe. Metal ball (4mm diameter) attached to palatal fossa of central incisor. Then, periapical radiograph was taken according to long cone paralleling technique. After film scan, labial alveolar bone profile reproduced along interproximal bone and apical ends of gutta-percha cones on computer screen. By utilizing computer program, the distance from height of interproximal bone to the labial bone crest in central incisor-central incisor and central incisor-lateral incisor area was measured and converted to real distance by using vertical length of metal ball on film. After measuring crown length & width of central incisor, the 10 individuals ranked lowest GW/L ratio (crown width/length ratio) and the 10 ranked highest were selected as having a long-narrow(group N), or a short-wide(group W) form of the central incisors. Means of the distance from height of interproximal bone to the labial bone crest of group N, W were calculated and compared by means of independent t-test. The results were as follows: 1. Mean distance from the height of the interproximal bone to the labial bone crest was $3.5{\pm}0.7mm$ between two central incisor, and $2.8{\pm}0.6mm$ between central and lateral incisor. 2. Mean GW/L ratio of group N was 0.57, and group W was 0.8. Mean distance from the height of the interproximal bone to the labial bone crest of group N was higher than group W in both measured area(measurements of group N, W were $3.9{\pm0.2mm$ and $3.5{\pm}0.2mm$ between two central incisor, $3.0{\pm}0.2mm$ and $2.8{\pm}0.2mm$ between central and lateral incisor), but there were no statistically significant differences when the groups were compared. Within the limits of the present study, there was a tendency that subjects with long-narrow teeth have more scalloped alveolar bone profile than subjects with short-wide teeth in upper anterior area, but no statistically significant differences were found.