• Title/Summary/Keyword: Pontic

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A study on the difference analysis between an ideal and a clinical shape in case of manufacturing a metal-ceramic pontic substructure (금속-도재 가공치 하부구조 제작에서 이상적인 형태와 임상에서 사용되는 형태의 차이 분석)

  • Kim, Wook-Tae;Im, Su-Yeon
    • Journal of Dental Rehabilitation and Applied Science
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    • v.32 no.1
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    • pp.8-15
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    • 2016
  • Purpose: The purpose of this research is to determine whether pontic metal substructures, which are currently used in clinical surgeries, are designed appropriately and identify the problems that can occur due to their shape, size, and position. Then it aimed to emphasize the importance of making and designing pontic metal substructures based on basic principles. Materials and Methods: This research measured pontic basal surface (P1) used sample metal substructures in this study, gingiva margin (P2), and the porcelain thickness of maximum infrabulge of labial surface around 1/3 of cervix dentis (P3). One-way ANOVA analysis was carried out to test the differences among groups, Tukey Honestly Significant Difference Test was conducted for statistical analysis among groups. Results: For porcelain thickness and SD value, the P1 part was $1.2-1.8({\pm}0.17)mm$ for experimental group 1, $1.2-1.7({\pm}0.17)mm$ for experimental group 2, and $0.4-2.8({\pm}0.92)mm$ for experimental group 3. Next, the P2 part was $1.4-1.6({\pm}0.07)mm$ for experimental group 1, $1.3-1.8({\pm}0.07)mm$ for experimental group 2, and $0.5-2.7({\pm}0.67)mm$ for experimental group 3. The P3 part was $1.4-1.7({\pm}0.10)mm$ for experimental group 1, $1.5-2({\pm}0.10)mm$ for experimental group 2, and $0.9-3.1mm({\pm}0.90)$ for experimental group 3. There was no significance when One-way ANOVA analysis/Tukey Honestly Significant Difference Test was conducted for statistical analysis among groups (P > 0.05). Conclusion: The suggested metal substructures can be used clinically as they meet the requirements that pontic must have.

A STUDY ON THE STRESS DISTRIBUTION OF CANTILEVER BRIDGE UNDER MAXIMUM BITE FORCE AND FUNCTIONAL BITE FORCE USING THREE DIMENSIONAL FINITE ELEMENT METHOD (최대교합 및 기능교합시 하악구치부 연장가공의치에 발생하는 응력에 대한 삼차원 유한요소법적 연구)

  • Park Chang-Keun;Lee Sun-Hyung;Chung Hun-Young;Yang Jae-Ho
    • The Journal of Korean Academy of Prosthodontics
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    • v.32 no.4
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    • pp.484-514
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    • 1994
  • Cantilever bridge is widely used by mny clinicians, but its worst mechanical character, so called Class I lever system, makes dentists hesitate to restore the missing tooth with it. Therefore it is important to study stress of the cantilever bridge. In this study, two models of cantilever bridges that restores the missing mandibular second molar with two abutment teeth were constructed. One model was a type of cantilever bridge supported by a normal alveolar bone, the other one was supported by an alveolar bone resorbed to its 1/3 of root length. Maximum bite force(550N) and funtional maximum bite force(300N) were vertically applied to the distal end of the pontic, distal 1/3, and distal half of the pontic. And each force was also applied to centric occlusal contacts as a distributed force. Total 16 loading cases were compared and analyzed with 3-dimensional finite element method. The results were as follows: 1. The stress was concentrated on the joint of the pontic and the retainer, grooves, and distal cervical margin of the posterior retainer. 2. In case of maximum bite force(550N) at the end of the pontic, the risk of fracture at the joint of the pontic and the retainer was high. 3. In case of distributed force in centric occlusion and functional maximum bite force(300N), the stresses were less than the yield strength of the type VI gold for any loading cases. 4. In case of alveolar bone resorption, the occlusal force to the cantilever pontic caused more stress on the root apex and less stress on the alveolar crest region of the distal surface of the posterior abutment. 5. In case of alveolar bone resorption, the displacement was larger than that of normal alveolar bone in all loading cases.

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Pontic site development and soft tissue transfer of the esthetic area: a case report (심미적 부위에서 가공치 하방 잔존치조제의 형성 및 연조직 복제 모형을 이용한 고정성 보철물 수복증례)

  • Kim, Hak-Cheon;Noh, Kwantae;Kwon, Kung-Rock;Kim, Hyeong-Seob
    • The Journal of Korean Academy of Prosthodontics
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    • v.51 no.4
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    • pp.323-331
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    • 2013
  • Soft tissue collapse around prepared teeth and pontic is inevitable after removal of the provisional restoration during the impression taking procedures. When inserting gingival retraction cord, soft tissue is displaced to an undesired contour. Viscosity of impression material also causes gingival displacement. Therefore, the consideration to transfer the prosthetically contoured soft tissue to master cast is required, especially in the esthetic area. In this report, the methods to maintain the soft tissue contour and transfer to the mastercast will be introduced. Harmonious contour of the soft tissue can be achieved with provisional restoration and be transferred to the master cast with two different techniques mentioned in this case report.