• 구강회복응용과학지
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• 제28권3호
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• pp.253-268
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• 2012

수직적, 수평적 골흡수가 심한 환자에서 임플란트를 이용한 전악수복의 경우 경조직과 연조직 이식을 통해서 임플란트를 원하는 위치에 식립할 수도 있지만, 치은과 치아의 기능과 심미를 회복할 수 있는 fixed detachable prostheses를 대체 술식으로 사용할 수도 있다. 이러한 증례에서 다양한 재료가 수복물의 제작에 사용 가능하지만, metal/acrylic 보철물에서는 레진치아의 파절 및 탈락이 일어날 수 있고, metal/ceramic 혹은 zirconia/ceramic 보철물에서는 도재의 chipping이나 파절과 같은 문제가 발생할 수 있다. 이에 최근에 심미적이면서도 기능적인 보철수복을 위해 zirconia에 도재를 축성하지 않고 임상적으로 적용가능한 monolithic zirconia framework이 출시되어 사용되고 있다. 본 임상 증례는 심미적인 요구도가 높은 완전 무치악 환자에서 임플란트를 식립하고 chipping이나 파절의 위험을 감소시키기 위해 monolithic zirconia framework을 이용해 만들어진 complete fixed detachable 보철물을 이용한 수복에 대해 보고하고자 한다. 이번 증례에서 보철물은 심미적, 기능적으로 만족스러웠으며, 2년 간의 정기검사에서 임상적인 합병증은 보고되지 않았다.

• The Journal of Advanced Prosthodontics
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• 제7권3호
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• pp.264-270
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• 2015

This report describes the case of an edentulous patient with an atrophic maxilla and severe class III malocclusion. Prosthetic rehabilitation was performed using CAD/CAM techniques for manufacturing an implant-supported overdenture with horizontal insertion. A vestibulo-lingual insertion overdenture is a precision prosthesis with a fixation system affording a good fit between the primary and secondary structure. Both structures exhibit passive horizontal adjustment. This treatment option requires the same number of implants as implant-supported fixed dentures. The horizontal assembly system prevents the prosthesis from loosening or moving in response to axial and non-axial forces. The technique was used to rehabilitate a patient presenting an atrophic upper maxilla, with the insertion of 8 implants. No complications were reported at follow-up 3, 6 and 12 months after fitting of the prosthesis. This system offers solutions to the clinical and laboratory complications associated with hybrid prostheses, concealing emergence of the chimneys and improving implant-prosthesis hygiene.

• 대한치과보철학회지
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• 제46권3호
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• pp.290-297
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• 2008

STATEMENT OF PROBLEM: Implant-supported fixed cantilever prostheses are influenced by various biomechanical factors. The information that shows the effect of implant number and position of cantilever on stress in the supporting bone is limited. PURPOSE: The purpose of this study was to investigate the effect of implant number variation and the effect of 2 different cantilever types on stress distribution in the supporting bone, using 3-dimensional finite element analysis. MATERIAL AND METHODS: A 3-D FE model of a mandibular section of bone with a missing second premolar, first molar, and second molar was developed. $4.1{\times}10$ mm screw-type dental implant was selected. 4.0 mm height solid abutments were fixed over all implant fixtures. Type III gold alloy was selected for implant-supported fixed prostheses. For mesial cantilever test, model 1-1 which has three $4.1{\times}10$ mm implants and fixed prosthesis with no pontic, model 1-2 which has two $4.1{\times}10$ mm implants and fixed prosthesis with a central pontic and model 1-3 which has two $4.1{\times}10$ mm implants and fixed prosthesis with mesial cantilever were simulated. And then, 155N oblique force was applied to the buccal cusp of second premolar. For distal cantilever test, model 2-1 which has three $4.1{\times}10$ mm implants and fixed prosthesis with no pontic, model 2-2 which has two $4.1{\times}10$ mm implants and fixed prosthesis with a central pontic and model 2-3 which has two $4.1{\times}10$ mm implants and fixed prosthesis with distal cantilever were simulated. And then, 206N oblique force was applied to the buccal cusp of second premolar. The implant and superstructure were simulated in finite element software(Pro/Engineer wildfire 2.0). The stress values were observed with the maximum von Mises stresses. RESULTS: Among the models without a cantilever, model 1-1 and 2-1 which had three implants, showed lower stress than model 1-2 and 2-2 which had two implants. Although model 2-1 was applied with 206N, it showed lower stress than model 1-2 which was applied with 155N. In models that implant positions of models were same, the amount of applied occlusal load largely influenced the maximum von Mises stress. Model 1-1, 1-2 and 1-3, which were loaded with 155N, showed less stress than corresponding model 2-1, 2-2 and 2- 3 which were loaded with 206N. For the same number of implants, the existence of a cantilever induced the obvious increase of maximum stress. Model 1-3 and 2-3 which had a cantilever, showed much higher stress than the others which had no cantilever. In all models, the von Mises stresses were concentrated at the cortical bone around the cervical region of the implants. Meanwhile, in model 1-1, 1-2 and 1-3, which were loaded on second premolar position, the first premolar participated in stress distribution. First premolars of model 2-1, 2-2 and 2-3 did not participate in stress distribution. CONCLUSION: 1. The more implants supported, the less stress was induced, regardless of applied occlusal loads. 2. The maximum von Mises stress in the bone of the implant-supported three unit fixed dental prosthesis with a mesial cantilever was 1.38 times that with a central pontic. The maximum von Mises stress in the bone of the implant-supported three-unit fixed dental prosthesis with a distal cantilever was 1.59 times that with a central pontic. 3. A distal cantilever induced larger stress in the bone than a mesial cantilever. 4. A adjacent tooth which contacts implant-supported fixed prosthesis participated in the stress distribution.

• 대한치과보철학회지
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• 제57권4호
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• pp.342-349
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• 2019

목적: 이 연구의 목적은 구치부 영역에서 임플란트 지지 고정 보철물의 재료에 따른 생존율과 성공률을 후향적으로 조사하는 것이다. 또한 임플란트 지지 고정성 보철물에서 발생하는 합병증의 양상을 관찰하고 실패에 영향을 주는 요인을 평가하는 것이다. 대상 및 방법: 2011년 1월부터 2018년 6월 사이에 전북대학교 치과병원 치과보철과에서 한 명의 보철전문의에 의해 구치부 임플란트 보철 수복을 시행한 환자를 대상으로 하였다. 의료기록을 통해 환자의 성별, 연령, 보철물의 재료, 위치, 유형 및 합병증을 조사하였다. 생존율 및 성공률 분석을 위해 Kaplan-Meier 분석법을 이용하였으며, 집단간 비교를 위해 Log-rank test를 사용하였다. 또한 Cox proportional hazards model을 이용하여 위험요소가 성공률에 미치는 영향을 분석하였다. 결과: 총 245명의 환자에서 364개의 임플란트 보철물이 관찰되었으며, 평균 추적관찰기간은 17.1개월이었다. 전체 임플란트 보철물의 3년, 5년 누적생존율은 각각 97.5%, 91.0%로 관찰되었으며, 총 5개의 임플란트 보철물이 실패하여 제거되었다. 임플란트 보철물의 3년, 5년 누적성공률은 각각 61.1%, 32.9%로 관찰되었으며, 재료, 성별, 연령, 보철물의 위치, 유형은 누적성공률에 영향을 미치지 않았다 (P > .05). 합병증은 인접면 접촉 상실 (53건), 유지력 상실 (17건), 임플란트 주위 점막염 (12건), 저위교합 (4건) 등의 순으로 발생하였다. 결론: 구치부에서 임플란트 지지 고정성 보철물의 높은 누적생존율을 고려할 때, 임플란트는 수복 재료와 상관없이 구치부에서 치아를 대체할 수 있는 신뢰할만한 치료방법으로 생각된다. 그러나 합병증이 빈번히 발생하기 때문에 정기적인 검사와 필요한 경우 수리 및 조정이 매우 중요하다.

• 구강회복응용과학지
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• 제17권4호
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• pp.283-305
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• 2001

The purpose of this study was to analyze the stress distribution of condylar regions and edentulous mandible with implant-supported cantilever prostheses on the certain conditions, such as amount of load, location of load, direction of load, fixation or non-fixation on the condylar regions. Three dimensional finite element analysis was used for this study. FEM model was created by using commercial software, ANSYS(Swanson, Inc., U.S.A.). Fixed model which was fixed on the condylar regions was modeled with 74323 elements and 15387 nodes and spring model which was sprung on the condylar regions was modeled with 75020 elements and 15887 nodes. Six Br${\aa}$nemark implants with 3.75 mm diameter and 13 mm length were incorporated in the models. The placement was 4.4 mm from the midline for the first implant; the other two in each quardrant were 6.5 mm apart. The stress distribution on each model through the designed mandible was evaluated under 500N vertical load, 250N horizontal load linguobuccally, buccal 20 degree 250N oblique load and buccal 45 degree 250N oblique load. The load points were at 0 mm, 10 mm, 20 mm along the cantilever prostheses from the center of the distal fixture. The results were as follows; 1. The stress distribution of condylar regions between two models showed conspicuous differences. Fixed model showed conspicuous stress concentration on the condylar regions than spring model under vertical load only. On the other hand, spring model showed conspicuous stress concentration on the condylar regions than fixed model under 250N horizontal load linguobuccally, buccal 20 degree 250N oblique load and buccal 45 degree 250N oblique load. 2. Fixed model showed stress concentration on the posterior and mesial side of working and balancing condylar necks but spring model showed stress concentration on the posterior and mesial side of working condylar neck and the posterior and lateral side of balancing condylar neck under vertical load. 3. Fixed model showed stress concentration on the posterior and lateral side of working condylar neck and the anterior and mesial side of balancing condylar neck but spring model showed stress concentration on the anterior sides of working and balancing condylar necks under horizontal load linguobuccally. 4. Fixed model showed stress concentration on the posterior side of working condylar neck and the posterior and lateral side of balancing condylar neck but spring model showed stress concentration on the anterior side of working condylar neck and the anterior and lateral side of balancing condylar neck under buccal 20 degree oblique load. 5. Fixed model showed stress concentration on the anterior and lateral side of working condylar neck and the posterior and mesial side of balancing condylar neck but spring model showed stress concentration on the anterior side of working condylar neck and the anterior and lateral side of balancing condylar neck under buccal 45 degree oblique load.. 6. The stress distribution of bone around implants between two models revealed difference slightly. In general, magnitude of Von Mises stress was the greatest at the bone around the most distal implant and the progressive decrease more and more mesially. Under vertical load, the stress values were similar between implant neck and superstructure vertically, besides the greatest on the distal side horizontally. 7. Under horizontal load linguobuccally, buccal 20 degree oblique load and buccal 45 degree oblique load, the stress values were the greatest on the implant neck vertically, and great on the labial and lingual sides horizontally. After all, it was considered that spring model was an indispensable condition for the comprehension of the stress distributions of condylar regions.

• 대한치과보철학회지
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• 제44권5호
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• pp.526-536
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• 2006

Statement of problem : Use of fiber composite technology as well as development of nonmetal implant prosthesis solved many problems due to metal alloy substructure such as corrosion. toxicity, difficult casting, expensiveness and esthetic limit. After clinical and laboratory test, we could find out that fiber-reinforced composite prostheses have good mechanical properties and FRC can make metal-free implant prostheses successful. Purpose : The purpose of this study is to evaluate the flexural strength of implant fixed prosthesis using fiber reinforced composite. Material and methods : 2-implant fixture were placed in second premolar and second molar area in edentulous mandibular model, and their abutments were placed, and bridge prostheses using gold, PFG, Tescera, and Targis Vectris were fabricated. Tescera was made in 5 different designs with different supplements. Group I was composed by 3 bars with diameter 1.0mm and 5 meshes, 2 bars and 5 meshes for Group II, 1 bar and 5 meshes for Group III, and only 5 meshes were used for Group IV. And Group V is composed by only 3 bars. Resin (Tescera) facing was made to buccal part of pontic of gold bridge. All of gold and PFG bridges were made on one model, 5 Targis Vectris bridges were also made on one model, and 25 Tescera bridges were. made on 3 models. Each bridge was attached to the test model by temporary cement and shallow depression was formed near central fossa of the bridge pontic to let 5 mm metal ball not move. Flexual strength was marked in graph by INSTRON. Results : The results of the study are as follows. The initial crack strength was the highest on PFG. and in order of gold bridge Tescera I, Tescera II, Targis vectris, Tescera IV, Tescera III, and Tescera V. The maximum strength was the highest on gold bridge, and in order of PFG, Tescera I, Tescera IV Tescera II, Targis vectris, Tescera III, and Tescera V. Conculsions : The following conclusions were drawn from the results of this study. 1. Flextural strength of implant prosthesis using fiber reinforced composite was higher than average posterior occlusal force. 2. In initial crack strength, Tescera I was stronger than Tescera V, and weaker than PFG. 3. Kinds and number of auxillary components had an effect on maximum strength, and maximum strength was increased as number of auxillary components increased. 4 Maximum strength of Tescera I was higher than Targis vectris, and lower than PFG.

• 대한치과보철학회지
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• 제50권4호
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• pp.318-323
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• 2012

임플란트 보철물은 유지방법에 따라 크게 나사 유지형 보철물(screw-retained prosthesis)과 시멘트 유지형 보철물(cement-retained prosthesis)로 나눌 수 있으며, 이들 장점을 고려하여 만든 나사-시멘트 유지형 보철물(SCRP: screw and cement retained implant prosthesis)이있다. 나사-시멘트 유지형 보철물은 임플란트 지대주와 상부 보철물 사이의 시멘트 층이 보철물 제작 과정에서 발생하는 여러 오차를 보상하여 수동적 적합을 얻을 수 있으며, 임상 및 기공 과정이 간단한 장점과 더불어 임플란트 보철의 유지 관리를 위해 필수적인 탈 부착(retrievability)이 가능하다. 본 증례에서는 완전 무치악 환자를 대상으로 상, 하악에 각각 9, 8개의 임플란트(US II, OSSTEM, Seoul, Korea)를 식립하고 나사 구멍이 순측으로 향하는 부위는 시멘트 유지형, 다른 부위는 나사-시멘트 유지형태를 사용하여 복합형태의 나사-시멘트 보철물(SCP: screw-cement prosthesis)을 제작하였으며 3년 간의 정기 검사에서 기능과 심미적으로 만족할 만한 결과를 얻어 이를 보고하고자 한다.

• 대한치과보철학회지
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• 제36권4호
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• pp.615-643
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• 1998

The purpose of this study was to evaluate the effect of cantilever length, load, and implant number on the stress distribution of implant supported fixed prosthesis. In the replica of an edentulous human mandible, four or five implants were placed and spaced evenly between the mental foramina and symmetrical gold alloy cast superstructures with cantilever were fabricated. Strain gauges were placed in buccal and lingual side of implants. 9, 15, 21kg of loads at varying cantilever lengths were applied to the occlusal surface of fixed prostheses. The strains were recorded from each gauge and principal stresses were calculated The results were as follows : 1. Increasing the length of the cantilever increased the stresses on the bone supporting implants. and the ratio of increase became high as increasing the load. 2. In the model with four implants, the highest compressive stress was measured on lingual side of the first implants nearest loading point and the highest tensile stress was measured on buccal side of the second implants. 3. In the model with five implants, the highest compressive stress was measured on lingual side of the first implants nearest loading point. And the highest tensile stress was measured on buccal side of the second implants, and lingual side of the third implants. 4. There was no significant change of the magnitude of stress on the most distal imp]ant of non cantilevered side as increasing the cantilever length or load. 5. In general, the superstructure supported by five implants reduced the stress and was less affected by cantilever length compared to the support provided by four implants.

• Journal of Periodontal and Implant Science
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• 제50권2호
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• pp.97-105
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• 2020

Purpose: The present retrospective clinical study aimed to evaluate and compare the clinical and radiographic parameters, complications, and satisfaction in patients who received fixed prostheses supported by narrow-diameter implants (NDIs) in the anterior and posterior jaw. Methods: Patients aged ≥30 years who had NDI-supported fixed prostheses in the anterior or posterior region of either jaw for at least 2 years were included. Complications such as chipping of the crown; loosening or fracture of the screw, crown abutment, or implant; and loss of retention were recorded. Clinical peri-implant outcomes and crestal bone loss (CBL) were measured. A questionnaire was used to record responses regarding the aesthetics and function of the fixed restorations. Analysis of variance was used to assess the significance of between-group mean comparisons. The log-rank test was performed to analyze the influence of location and prosthesis type on technical complications. Results: Seventy-one patients (mean age: 39.6 years) provided informed consent with a mean follow-up duration of 53 months. Only bleeding on probing showed a statistically significant difference between NDIs in the anterior and posterior regions. The complication rate for NDIs in the posterior region was significantly higher than that for NDIs in the anterior region (P=0.041). For NDIs, CBL was significantly higher around splinted crowns than single crowns (P=0.022). Overall mean patient satisfaction was 10.34±3.65 on a visual analogue scale. Conclusions: NDIs in the anterior and posterior jaws functioned equally well in terms of periimplant soft and hard tissue health and offered acceptable patient satisfaction and reasonable complication rates.

• 구강회복응용과학지
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• 제30권1호
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• pp.71-80
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• 2014

골흡수가 심한 환자에서 임플란트를 이용한 전악 수복의 경우 치은과 치아의 외형을 심미적이면서도 기능적으로 회복하기 위해서는 보철물 제작에 있어 신중을 기해야 한다. 이러한 전악 수복 증례에서 CAD/CAM 시스템이 높은 정확성을 가지는 보철물 제작을 가능하게 함으로써 사용이 증가하고 있다. 최근에 임상에서 티타늄이나 지르코니아의 단점을 보완하면서 높은 생체적합성을 가지고 CAD/CAM 시스템으로 제작할 수 있는 팔라듐-은(Pd-Ag) 합금이 개발되어 사용되고 있다. 본 증례에서는 상악 전부 무치악 환자에서 임플란트를 식립하고 도재의 chipping이나 파절의 위험을 감소시키기 위해 Pd-Ag 합금을 이용해 제작된 임플란트 고정성 보철물로 수복한 환자에 대해 보고하고자 한다.