• The Journal of Advanced Prosthodontics
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• 제1권2호
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• pp.85-90
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• 2009

STATEMENT OF PROBLEM. Over the years, resin-bonded fixed partial dentures (RBFPDs) have gone through substantial development and refinement. Several studies examined the biomechanics of tooth preparation and framework design in relation to the success rate of RBFPDs and considered retention and resistance form essential for increase of clinical retention. However, these criteria required preparations to be more invasive, which violates not only the original intentions of the RBFPD, but may also have an adverse effect on retention due to loss of enamel, an important factor in bonding. PURPOSE. The object of this in vitro study was to compare the dislodgement resistance of the new types of RBFPDs, the conventional three-unit fixed partial denture, and conventional design of RBFPD (Maryland bridge). MATERIAL AND METHODS. Fifty resin mandibular left second premolars and second molars were prepared on dentiforms, according to the RBFPD design. After model fabrication (five group, n = 10), prostheses were fabricated and cemented with zinc phosphate cement. After cementation, the specimens were subjected to tensile loading at a cross head speed of 4 mm/min in a universal testing machine. The separation load was recorded and analyzed statistically using one-way analysis of variance followed by Duncan's multiple range test. RESULTS. Group V, the pin-retained RBFPDs, had the highest mean dislodgement resistance, whereas specimens of group II, the conventional RBFPDs, exhibited a significantly lower mean dislodgement resistance compared to the other 4 groups (P <.05). There were no significant differences between group I, III, and IV in terms of dislodgement resistance (P>.05). Group V had the highest mean MPa (N/$mm^2$) (P <.05). There was no significant difference between groups I, II, III and IV (P > .05). CONCLUSION. Within the limits of the design of this in vitro study, it was concluded that: 1. The modified RBFPDs which utilizes the original tooth undercuts and requires no tooth preparation, compared with the conventional design of RBFPDs, has significantly high dislodgement resistance (P < .05). 2. The modified RBFPDs which utilizes the original tooth undercuts and requires minimal tooth preparation, compared with the conventional FPDs, has significantly no difference in retention and dislodgement resistance)(P>.05). 3. The pin-retained FPDs showed a high dislodgement resistance compared to the conventional three-unit FPDs (P<.05).

• 대한치과보철학회지
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• 제49권2호
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• pp.106-113
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• 2011

연구 목적: 전통적인 초기의 접착성 고정성 보철물이 가능한 보존적이고 가역적인 치료를 추구했지만 유지력의 상실이 큰 문제가 되면서 임상적 성공률이 낮은 단점이 있었다. 이러한 한계를 극복하고자 하는 여러 연구들 중, 자연 치아의 언더컷과 구조물의 각기 다른 삽입로를 이용하여 유지력을 얻는 3-piece형태의 변형된 접착성 고정성 보철물이 제안되었다. 이 연구의 목적은 변형된 형태의 접착성 고정성 보철물을 이용하여 수복 치료를 받은 환자에 대한 후향적 연구를 통하여 임상가들의 상실치 수복을 위한 치료 계획 수립에 도움을 주고자 함이다. 연구 재료 및 방법: 한 개 혹은 그 이상의 치아가 상실되어 수복을 요하여 2007년부터 연세대학교 치과대학병원 보철과에 내원하여 자연치아의 언더컷과 구조물의 각기 다른 삽입로를 이용하는 변형된 형태의 접착성 고정성 보철물 수복 치료를 받은 23명의 환자중 주기적 검사가 가능한 21명을 대상으로, 후향적으로 임상 및 방사선 검사 결과를 평가하였다. 결과 및 결론: 자연치아의 언더컷과 구조물의 각기 다른 삽입로를 이용한 접착성 고정성 보철물을 이용한 21명증례, 71 unit의 최대 25개월 (평균 7개월)간의 후향적 연구에서 다음과 같은 결과를 얻었다. 1. 자연치아의 언더컷과 구조물의 각기 다른 삽입로를 이용한 접착성 고정성 보철물은 단기간의 follow-up 에서 보철물의 탈락, 파절등의 기계적인 실패가일어나지 않았다. 2. 보철물 주변의 치주조직은 비교적 안정되었다. 3. 방사선 사진상 유의성있는 골흡수를 보이지 않았다.

• Journal of Korean Dental Science
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• 제10권1호
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• pp.29-34
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• 2017

Purpose: The purpose of this study was to evaluate the microleakage of various types of resin-bonded fixed partial dentures (RBFPDs) after artificial aging. Materials and Methods: Forty models with missing first molar were fabricated using artificial resin teeth and were divided into four groups: Group A, conventional RBFPDs design; Group B, modified RBFPDs design; Group C, assembled 3-piece RBFPDs design; and Group D, assembled 3-piece RBFPDs with different occlusal rest positions. Half of the specimens underwent chewing simulation process (240,000 cycles, 50 N load, 1.7 Hz) and thermocycling (temperatures $5^{\circ}C{\sim}55^{\circ}C$, dwelling time 30 seconds) and the remaining 20 specimens didn't receive any treatment. All the specimens were immersed in 2% methylene blue solution for 24 hours to evaluate microleakage, and were sectioned at the middle part of abutment teeth. To evaluate the microleaskage, a dye penetration was calculated. Result: With artificial aging, cyclic loading and thermocycling, a 3-piece RBPFD and a 2-piece RBPFD using original tooth undercuts have significantly lower microleakge (P<0.05) compared to the conventional design of RBPFD and modified RBPFD. Conclusion: Within the limit of this experiment, the assembled RBFPDs exhibited a smaller microleakage than the conventional RBFPDs, implying that the assembled RBFPDs can be more effective for reducing the dislodgement of the RBFPDs.