• 대한치과보철학회지
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• 제36권1호
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• pp.150-165
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• 1998

For the purpose of evaluating the effect of both direct retainer design and bony absorption degree around abutment of indirect retainer on the supporting tissue of abutment of indirect retainer, dislodging force was transmitted to unilateral distal extension RPD bases. Analysis of stress distributed within the supporting tissue around abutment of indirect retainer was carried out. Using three-dimensional photoelastic stress analysis method and the conclusion is a follows. 1. According to the extent of force which the direct retainer of the most distal abutment tooth, the amount of force transmitted to the abutment tooth of indirect retainer was small. 2. Of all the cases, Mandibular first premolar which was used abutment tooth of indirect retainer, buccal, mesial and distal sides represented compression stress and lingual side represented tensile stress. 3. The more bone resorption of abutment tooth of indirect retainer, the more distortion of buccal and distal side of abutment tooth was existed and the extent of compression stress which was existed and distal side to abutment tooth was large. 4. When the alveolar bone around the abutment with indircet retainer is normal. The amount of force transmitted on abutment with indirect retainer was small in the order of Akers clasp, RPA clasp, RPI clasp. 5. When the alveolar bone around the abutment with indirect retainer has been absorbed 20% and 30%, the amount of force transmitted on abutment with indirect retainer was small in the order of RPA calsp, RPI clasp, Akers clasp. 6. When denture is displaced, shape of the direct retainer reciprocating abutment affect much the function of indirect retainer.

• 대한치과보철학회지
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• 제33권3호
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• pp.413-439
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• 1995

The purpose of this study was to evaluate the stress distribution developed in the supporting structures by mandibular distal extension removable partial dentures with 2 different direct retainer designs and with or without indirect retainer and abutment splinting. The examined direct retainers on the second bicuspid abutment tooth were Akers clasp and RPA clasp, the indirect retainer was located on the mesial fossa of the first bicuspid, and the first and second bicuspid were splinted in case of tooth splinting. Total 8 cases were compared and analyzed with 3-dimensional finite element method. 150N were applied vertically on the artificial teeth of the removable partial denture, and then stress distribution patterns were analyzed and compared. The results were as follows : 1. The forces transmitted to the abutment tooth were primarily from the occlusal rests. 2. The abutment tooth was displaced distally when the force was applied. The compressive stress was observed at the distal root surface of the abutment tooth and the tensile stress, at the mesial root surface. 3. The denture base was displaced posteriorly and inferiorly when the force was applied. At the more distal portion of the denture base, the greater displacement was observed.And the anterior portion of the major connector was displaced superiorly. 4. The occlusal rest placed on the distal part of the abutment tooth tended to tip the tooth more posteriorly than did one on the mesial part of that tooth. 5. Severe superior displacement was observed at the anterior portion of the major connector in case of removable partial dentures without indirect retainer. 6. In case of tooth-splinting, the stress was distributed through all the root surface of both abuments. In case of no tooth-splinting, the stress was concentrated on the distal root surface of the primary abutment.

• 대한치과보철학회지
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• 제28권2호
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• pp.183-197
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• 1990

The purpose of this study was to analyse the magnitude and distribution of stresses using a Photoelastic model from and distal - extension removable partial dentures With four designed indirect retainers. The designs of the indirect retainers were as follows : Design No. 1 : Aker's clasp on 1st bicuspid with no indirect retainer. Design No. 2 : Aker's clasp on 1st bicuspid with indirect retainer on canine. Design No. 3 : Extension of the reciprocal arm of Aker's clasp toward incisal rest on canine. Design No. 4 : Connection with the indirect retainer as in No. 2 and extension of reciprocal arm of Aker' s clasp. A photoelastic model was made of the epoxy resin(PL - 1) and hardner(PLH - 1) and coated with plastic cement -1(PC -1) at the lingual surface of the epoxy model and set with chrome - cobalt partial dentures. A unilateral vertical load of 10kg to the right 1st molar and a vertical load of 10kg to the middle portion of the metal bar crossing both the 1st molars of the right and left, were applied. With the use of specially designed jig, fixture; loading device and the reflective circular polariscope, we obtained the following results : 1. When the unilateral vertical load and the vertical load of the middle portion of the metal bar were applied, design No. 2, 3 and 4 exhibited the higher stress concentration at the root apices and their surrounding tissues of the primary and secondary abutment teeth. 2. When the unilateral vertical load applied to design No. 2,3 and 4 the root apices of the primary and secondary abutment teeth and their surrounding tissues and the nonloaded side of edentulous area exhibited and even stress distribution. 3. When the vertical load was applied, the stress concentration fringe in the primary and secondary abutment teeth was in the order of No. 1,4,2 and 3. 4. No.1 and 4 exhibited the higher distrorted stress concentration at the primary teeth and the edentulous area in the nonloaded side. 5. No.2 design reduced the stresses at the apices of the alveoli of the primary abutment teeth bilaterally as well as on the crest of the residual ridge on the nonloaded side. 6. No. 2 design exhibited the most favorable stress distribution.

• 대한치과교정학회지
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• 제41권6호
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• pp.447-453
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• 2011

Objective: We compared the shear bond strength (SBS) of lingual retainers bonded to bovine enamel with three different resins using direct and indirect methods. Methods: Both ends of pre-fabricated twisted ligature wires were bonded to bovine enamel surfaces using Light-Core, Tetric N-Flow, or Transbond XT. Phosphoric acid-etched enamel surfaces were primed with One-Step prior to bonding with Light-Core or Tetric N-Flow. Transbond XT primer was used prior to bonding with Transbond XT. After 24 hours in water at $37^{\circ}C$, we performed SBS tests on the samples. We also assigned adhesive remnant index (ARI) scores after debonding and predicted the clinical performance of materials and bonding techniques from Weibull analyses. Results: Direct bonding produced significantly higher SBS values than indirect bonding for all materials. The SBS for Light-Core was significantly higher than that for Tetric N-Flow, and there was no significant difference between the direct bonding SBS of Transbond XT and that of Light-Core. Weibull analysis indicated Light-Core performed better than other indirectly bonded resins. Conclusions: When the SBS of a wire retainer is of primary concern, direct bonding methods are superior to indirect bonding methods. Light-Core may perform better than Transbond XT or Tetric N-Flow when bonded indirectly.

• 대한치과교정학회지
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• 제32권2호통권91호
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• pp.143-153
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• 2002

콤포지트와 여러가닥 강선을 사용하여 제작된 접착식 보정장치는 심미적이며, 효과적인 보정장치라 할 수 있다. 이 연구는 접착식 보정장치의 전단접착강도를 측정하고, 접착식 보정장치의 제작 시 사용하는 여러가닥 강선 및 접착방법의 이상적인 조합을 제시하기 위해 디자인되었다. 교정치료를 위해 발거한 건전한 상하악 소구치 160개를 사용하여 80개의 시편을 제작하였다. 접착면적 및 강선의 길이, 콤포지트의 두께를 동일화하고, 직접접착 및 간접접착의 방법으로 여러가닥 강선을 접착하여 접착식 보정장치를 제작하였다. 만능시험기를 사용하여 각 시편에서의 전단접착강도 및 강선의 탈락시까지의 신장량을 측정하여, 다음과 같은 결론을 얻었다. 1. 6가닥, 0.0155인치의 강선에서 가장 큰 최대 접착강도를 보이고, 3가닥, 0.0195인치의 강선에서 가장 작은 최대 접착강도를 보였는데, 그 차이는 유의할 만큼 크지 않았다(p<0.05). 즉 강선의 직경 및 가닥수는 접착강도와 큰 연관성이 없다. 2. 3가닥, 0.015인치의 강선에서 가장 큰 신장량을 보여 주었고, 3가닥, 0.0195인치 강선에서 가장 작은 신장량을 보여주었다(p<0.05). 강선의 직경이 작을수록 신장량은 크게 나타났으나, 강선의 가닥수는 신장량과 큰 연관성이 없다. 3. 두 가지 접착방법의 비교에서 간접 접착술식을 사용했을 때 더 큰 접착강도 및 신장량을 보여 주었고, 통계적으로 유의한 차이를 나타냈다(p<0.05).

• 대한치과보철학회지
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• 제14권1호
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• pp.66-71
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• 1976

The purpose of this investigation was to evaluate the mouth preparation and design of removable partial dentures. A total of 187cases for the prefabricated partial denture frameworks in both maxillary and mandibular semi-dentulous situations (66 cases and 203 cases) was selected from this study. The evaluations of mouth preparation and design observed here involved the classification of edentulous spaces, status of abutment splinting with location, design of direct retainer and structure of maxillary major connector according to the incidence of both dental arches, ages, sexes and segment of semidentulousness. The analyzed results were as follows: 1) The order of frequency rate in removable partial denture construction was Class II (50.27%), Class I (36. 90%), Class III (10.69%), and Class IV (2.14 %). 2) The distribution on design of maxillary removable partial denture prosthesis was 33.22% and 64.11% in mandibular removable partial denture prosthesis. 3) The age distribution of removable partial denture prosthesis was prominent after40 years (41.71%). 4) The design pattern of maxillary major connectors was in order of anteroposterior bar, single palatal bar, palatal strap, U-shape connector. 5) The design pattern of direct retainer was in order of Aker's clasp, I-bar clasp, backaction clasp, cuspid universal clasp. 6) The abutment for partial denture clasp splinted between premolar and premolar and its frequency rate revealed 53.44%. 7) It seemed that the location and design of the indirect retainer showed accepatble limit.

• 대한치과보철학회지
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• 제47권3호
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• pp.320-327
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• 2009

연구목적: 가철성 국소의치의 장기적 예후를 보증하고자 하는 많은 노력에도 불구하고, 부적절한 제작 및 유지관리로 인해 가철성 국소의치와 연관된 합병증은 여전히 관측되고 있다. 이에 본 연구에서는 가철성 국소의치의 임상적 상태를 조사하여 보철 진료의 임상적 참고자료와 후학연구의 기초자료로 도움이 되고자 하였다. 연구 재료 및 방법: 2008년 1월에서 8월까지 부산대학교병원 치과 보철과에 내원한 환자 중 가철성 국소의치를 사용 중인 성인을 대상으로 가철성 국소의치와 지대치에 연관된 임상적 상태를 조사 평가하였다. 결과 및 결론: 본 연구의 결과는 다음과 같았다. 1. 전체 가철성 국소의치의 추정수명은 4.0년이었고, 평균 장착 기간은 5.3년이었다. 2. 가철성 국소의치 성공, 실패 평가에서 45개의 보철물이 실패했으며. 전체 369개의 지대치 중 18개 (4.9%)의 지대치가 상실되었다. 3. 가철성 국소의치의 상, 하악 위치, Kennedy 분류, 대합치의 조건에 따른 추정 수명은 차이가 없었으며, 성공률과 실패율도 차이가 없었다 (P > .05). 4. 가철성 국소의치의 주연결장치는 상악에서 palatal plate 주연결장치 (55%)가 가장 많이 설계되었으며, 하악에서는 linguoplate 주연결장치 (52%), lingual bar 주연결장치 (45.3%) 순으로 조사되었다. 5. 가철성 국소의치의 직접유지장치는 circumferential type (74%), bar type (15%), 기타 (11%) 순으로 조사되었다. 6. 전체 140개의 I급과 II급 가철성 국소의치 중 63%의 보철물에 간접유지장치가 설계되어 있었다. 7. 보철물의 주된 결함은 과도한 구치부 인공치 마모 (27.9%), 보철물의 손상 (23.2%), 안정성의 부족 (22.6%) 순으로 발생하였으며, 전체 보철물의 81%가 최소한 1개의 결함을 가지고 있었다.

• 대한치과의사협회지
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• 제49권2호
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• pp.77-84
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• 2011

The benefits of implant supported overdenture are readily apparent for the fully edentulous patients and have been well documented, however, there is deficiency of the studies regarding the combination of implants with removable partial dentures for partially edentulous patients. The purpose of this article is to review the literature concerning implants with removable partial dentures and evaluate the evidence for this clinical approach. Through many clinical case reports and studies we have searched from a broad variety of journals, we present the six considerations needed to contemplate respecting implants with removable partial denture in partially edentulous patients. First, the connection between abutment tooth and removable partial denture has to be rigid and the link between implant and removable partial denture should be hinged. Second, a mesial rest acts better in the point of force distribution for distal extension removable partial denture and splinting between implants is also a favorable choice. Third, T bar has an advantage for implants which are used as abutments in distal extension removable partial denture. Forth, as we all known functional impression is better way to reproduce movement for distal extension removable partial denture. Fifth, indirect retainer and guiding plane on the proximal surfaces of terminal abutment teeth are important in preventing denture base lifting. Sixth, implants in conjunction with removable partial denture is superior in the esthetic and phonetic as well as cost-effective point of view. We also suggest that which place we should install implants for force distribution and which diameter and length of implants should be used. in this review article, we recommend to locate the implant near of the abutment tooth for esthetics or near of first molar position for good stress distribution. The diameter and length of implant also influence to stress distribution. When we compare to conservative partial denture, patients go for removable partial denture using implants due to convenience, better support and retention according to several studies. But it is true that we need to study more on this subject and collect long term follow up cases before we discuss on it. So it is enough to bring this subject into the surface of prosthetic treatment by this article.