• 대한치과기공학회지
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• 제12권1호
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• pp.121-124
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• 1990

The purpose of this study was to evaluate the effect of three different retention forms on the bond strength when complete denture repaired. Total 75 samples were divided into 3 groups(Dove-tail form, bevel form, rabbit form). The completed resin samples were compressed in Instron Testing Machine until gross fracture occurred to examine the effect on the bond strength of resin base. The results of the experiment were as follows : 1. The difference of bond strength according to three retention forms were not statistically significant(P>0.05). 2. Dove-tail form was strongest to bond strength among the three retention forms.

• 대한치과보철학회지
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• 제61권2호
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• pp.113-124
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• 2023

목적: 본 연구의 목적은 임플란트 보철물의 종류 및 특성과 생존율 분석을 통해 성공률을 높이는데 도움이 되는 데에 있다. 대상 및 방법: 원광대학교 치과대학 산본치과병원에서 2011~2020년에 식립한 임플란트 중 한 명의 보철전문의에 의해 수복된 사례에 대하여 그 특성과 실패에 대한 상관관계 등을 조사하였다. 실패의 원인은 골유착 실패, 임플란트주위염, 고정체 파절, 지대주 파절, 나사 파절, 나사 풀림, 보철물 파절, 보철물 유지력 상실 등으로 분류했다. 보철방식, 캔틸레버 여부, 식립 위치 등과 임플란트 실패와의 연관성을 분석했다. 결과 분석은 SPSS ver 25.0 (IBM, Chicago, IL, USA)을 이용하여 Chi-square test, Kaplan-Meier 생존분석 등을 통하여 도출했다. 결과: 총 2587개의 임플란트가 식립되었으며, 그 중 1141개의 임플란트가 단일관(Single Crown)으로, 1446개의 임플란트가 고정성 국소의치(Fixed Partial Denture)로 수복되었고 누적생존율은 88.1%이었다. SC의 성공률은 86.2% (984개), FPD의 성공률은 89.6% (1295개)로 통계적으로 유의한 차이를 보였으며 그 중 유의한 차이가 있었던 요인은 지대주 파절, 나사 파절, 나사 풀림 등이었다 (P < .05). 결론: 10년간의 추적조사 결과 생물학적인 요인보다는 생역학적인 요인으로 인한 실패가 더 많이 발생했고 임플란트의 성공률은 보철방식 별로 상이했으며 영향을 미치는 요인도 상이했다. 추후 임플란트의 성공에 관한 추가적인 연구가 더 필요할 것이다.

• The Journal of Advanced Prosthodontics
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• 제13권4호
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• pp.226-236
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• 2021

PURPOSE. This study aimed to evaluate the effect of incorporating zirconium oxide nanoparticles (nano-ZrO₂) in polymethylmethacrylate (PMMA) denture base resin on flexural properties at different material thicknesses. MATERIALS AND METHODS. Heat polymerized acrylic resin specimens (N = 120) were fabricated and divided into 4 groups according to denture base thickness (2.5 mm, 2.0 mm, 1.5 mm, 1.0 mm). Each group was subdivided into 3 subgroups (n = 10) according to nano-ZrO₂ concentration (0%, 2.5%, and 5%). Flexural strength and elastic modulus were evaluated using a three-point bending test. One-way ANOVA, Tukey's post hoc, and two-way ANOVA were used for data analysis (α = .05). Scanning electron microscopy (SEM) was used for fracture surface analysis and nanoparticles distributions. RESULTS. Groups with 0% nano-ZrO₂ showed no significant difference in the flexural strength as thickness decreased (P = .153). The addition of nano-zirconia significantly increased the flexural strength (P < .001). The highest value was with 5% nano-ZrO₂ and 2 mm-thickness (125.4 ± 18.3 MPa), followed by 5% nano-ZrO₂ and 1.5 mm-thickness (110.3 ± 8.5 MPa). Moreover, the effect of various concentration levels on elastic modulus was statistically significant for 2 mm thickness (P = .001), but the combined effect of thickness and concentration on elastic modulus was insignificant (P = .10). CONCLUSION. Reinforcement of denture base material with nano-ZrO₂ significantly increased flexural strength and modulus of elasticity. Reducing material thickness did not decrease flexural strength when nano-ZrO₂ was incorporated. In clinical practice, when low thickness of denture base material is indicated, PMMA/nano-ZrO₂ could be used with minimum acceptable thickness of 1.5 mm.

• 대한치과보철학회지
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• 제42권2호
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• pp.125-132
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• 2004

Statements of problem: All ceramic fixed partial denture cores can be made by the slip casting method and the advanced alumina tape method. The fracture resistance of these core connector areas is relatively low. Purpose: The purpose of this study is to standardize the appropriate volumetric figure and location of the connectors in the alumina core fabricated in alumina tape to be used in fixed partial dentures by way of topology optimization. Material and method: A maxillary anterior three-unit bridge alumina core with teeth form and surrounding periodontal apparatus model was used to ultimately design the most structurally rigid form of the connector. Loadings from a $0^{\circ}$, $45^{\circ}$ and $60^{\circ}$ to the axis of each tooth were applied and analyzed with the 3-D finite element analysis method. Using the results from these experiments, the topology optimization was applied and the optimal reinforcement layout of connector was obtained and the detail shape in the fixed partial denture core was designed. Results: The modified prosthesis with the form of a bulk in the lower lingual surface of the connector in the event, reduced the stress concentration up to 20% in the 3-D FEA. Conclusion: The formation of a bulk in the lower lingual connector area of an alumina core for a fixed partial denture decreases the stress to a clinically favorable measure but does not harm the esthetic point of view. This result illustrates the possibility of clinical application of the modified form designed by the topology optimization method.

• 구강회복응용과학지
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• 제33권4호
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• pp.321-328
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• 2017

무치악은 총의치나 임플란트 보철물로 수복이 가능하며 임플란트를 이용한 피개의치는 총의치보다 유지와 안정이 우수하고, 임플란트 고정성 보철물에 비해 저렴하고 심미적이다. CM $LOC^{(R)}$ $Pekkton^{(R)}$ 어태치먼트는 여자부가 poly-ether-ketone-ketone으로 마모저항성이 뛰어나다. 한편, SR Ivocap system은 가압주사성형법으로 의치의 수직고경 변화가 적고 강도가 우수하다. 본 증례에서 상악은 4개의 임플란트 식립 후 CM $LOC^{(R)}$ $Pekkton^{(R)}$ 어태치먼트와 SR Ivocap system을 이용한 임플란트 유지 피개의치를, 하악은 가철성 국소의치를 제작하였고 심미적 및 기능적으로 만족스러운 결과를 얻었기에 이를 보고하는 바이다.

• 대한치과보철학회지
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• 제58권4호
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• pp.300-305
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• 2020

목적: 인공치의 표면처리가 3D 프린팅 의치상레진과의 전단결합강도에 미치는 영향을 알아보고 임상적용에 있어 참고하기 위함이다. 재료 및 방법: 3D 프린팅 의치상레진을 3D 프린터를 이용하여 시편을 제작하였고, 인공치의 표면처리는 sandblasting, 프라이머의 적용 유무에 따라 5가지 군으로 나누어, 각 군마다 10개씩 진행하였다. Universal testing machine을 이용하여 전단 결합 강도를 측정하였고, 측정값은 one-way ANOVA로 통계분석 후 Turkey test를 통해 사후검정하였다. 이후 파절된 시편을 주사전자현미경을 이용하여 관찰하였다. 결과: 평균전단결합강도는 표면 처리 하지 않은 군에서 가장 낮은 값을 나타내었으며, 프라이머 처리한 군에서 유의하게 높은 결과 값을 나타내었다(P < .05). 또한 프라이머 처리한 군에서 대부분 응집파절을 나타내었다. 결론: 3D 프린팅 의치상레진에 인공치를 결합 시 인공치의 기계적·화학적 표면처리는 전단결합강도를 증가시켜 3D 프린팅 방식을 사용하여 의치를 제작할 경우 기계적·화학적 표면처리를 통해 인공치의 탈락을 줄일 수 있으며, 특히 sandblasting 과 프라이머를 처리하는 방법이 추천된다.

• 대한치과보철학회지
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• 제62권1호
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• pp.54-63
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• 2024

장기간 사용된 임플란트 피개의치는 부착장치의 마모와 전치부 교합집중, 인공치 파절, 의치의 회전 등을 보일 수 있다. 이러한 문제점은 추가적인 임플란트 식립을 이용한 임플란트보조 국소의치(IARPD, implant assisted removable partial denture)로의 전환으로 개선할 수 있다. 본 증례는 임플란트 피개의치를 사용하는 3급 악간관계 환자에서 전치부에 집중된 교합을 분산하고 의치의 회전방지를 위해 서베이드 크라운을 이용한 IARPD으로 전환하였다. 여러 단계의 임시수복물을 통해 적절한 기능과 심미를 가진 최종보철물의 형태를 결정하였으며 최종 보철물의 적절한 구치부 교합과 임플란트 주위 변연골 유지를 보였기에 이를 보고하는 바이다.

• 대한치과보철학회지
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• 제41권6호
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• pp.762-771
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• 2003

Statement of problem. In dentistry, the minimally prepared inlay resin-bonded fixed partial denture (FPD) made of new ceromer / fiber-reinforced composite (FRC) was recently introduced. However, the appropriate dimensions for the long-term success and subsequent failure strength are still unknown. Purpose. The aim of this study was to investigate the most fracture-resistible thickness combination of the ceromer / FRC using a universal testing machine and an AE analyzer. Material and Methods. A metal jig considering the dimensions of premolars and molars was milled and 56-epoxy resin dies, which had a similar elastic modulus to that of dentin, were duplicated. According to manufacturer's instructions, the FRC beams with various thicknesses (2 to 4 mm) were constructed and veneered with the 1 or 2 mm-thick ceromers. The fabricated FPDs were luted with resin cement on the resin dies and stored at room temperature for 72 hours. AE (acoustic emission) sensors were attached to both ends, the specimens were subjected to a compressive load until fracture at a crosshead speed of 0.5 mm/min. The AE and failure loads were recorded and analyzed statistically. Results. The results showed that the failure strength of the ceromer/FRC inlay FPDs was affected by the total thickness of the connectors rather than the ceromer to FRC ratio or the depth of the pulpal wall. Fracture was initiated from the interface and propagated into the ceromer layer regardless of the change in the ceromer / FRC ratio. Conclusion. Within the limitations of this study, the failure loads showed significant differences only in the case of different connector thicknesses, and no significant differences were found between the same connector thickness groups. The application of AE analysis method in a fiber-reinforced inlay FPD can be used to evaluate the fracture behavior and to analyze the precise fracture point.

• The Journal of Advanced Prosthodontics
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• 제2권4호
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• pp.134-141
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• 2010

PURPOSE. The objective of this study was to evaluate fracture strength of collarless metal-ceramic FPDs according to their metal coping designs. MATERIALS AND METHODS. Four different facial margin design groups were investigated. Group A was a coping with a thin facial metal collar, group B was a collarless coping with its facial metal to the shoulder, group C was a collarless coping with its facial metal 1 mm short of the shoulder, and group D was a collarless coping with its facial metal 2 mm short of the shoulder. Fifteen 3-unit collarless metal-ceramic FPDs were fabricated in each group. Finished FPDs were cemented to PBT (Polybutylene terephthalate) dies with resin cement. The fracture strength test was carried out using universal testing machine (Instron 4465, Instron Co., Norwood MA, USA) at a cross head speed of 0.5 mm/min. Aluminum foil folded to about 1 mm of thickness was inserted between the plunger tip and the incisal edge of the pontic. Vertical load was applied until catastrophic porcelain fracture occurred. RESULTS. The greater the bulk of unsupported facial shoulder porcelain was, the lower the fracture strength became. However, there were no significant differences between experimental groups (P > .05). CONCLUSION. All groups of collarless metal-ceramic FPDs had higher fracture strength than maximum incisive biting force. Modified collarless metal-ceramic FPD can be an alternative to all-ceramic FPDs in clinical situations.

• The Journal of Advanced Prosthodontics
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• 제4권4호
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• pp.204-209
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• 2012

PURPOSE. The aim of this systematic review is to address treatment outcomes of Mandibular implant overdentures relative to implant survival rate, maintenance and complications, and patient satisfaction. MATERIALS AND METHODS. A systematic literature search was conducted by a PubMed search strategy and hand-searching of relevant journals from included studies. Randomized Clinical Trials (RCT) and comparative clinical trial studies on mandibular implant overdentures until August, 2010 were selected. Eleven studies from 1098 studies were finally selected and data were analyzed relative to number of implants. RESULTS. Six studies presented the data of the implant survival rate which ranged from 95% to 100% for 2 and 4 implant group and from 81.8% to 96.1% for 1 and 2 implant group. One study, which statistically compared implant survival rate showed no significant differences relative to the number of implants. The most common type of prosthetic maintenance and complications were replacement or reattaching of loose clips for 2 and 4 implant group, and denture repair due to the fracture around an implant for 1 and 2 implant groups. Most studies showed no significant differences in the rate of prosthetic maintenance and complication, and patient satisfaction regardless the number of implants. CONCLUSION. The implant survival rate of mandibular overdentures is high regardless of the number of implants. Denture maintenance is likely not inflenced substantially by the number of implants and patient satisfaction is typically high again regardless os the number of implants.