• 제목/요약/키워드: Retentive force

검색결과 48건 처리시간 0.028초

WEAR BEHAVIOR OF ATTACHMENTS FOR IMPLANT RETAINED OVERDENTURE ACCORDING TO MATERIAL IN VITRO

  • Lee Seok-Hyung
    • 대한치과보철학회지
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    • 제41권6호
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    • pp.747-761
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    • 2003
  • Statement of problem. The proper materials of attachments for implant retained overdenture are unknown, such as the correlation between retention and abrasion, as well as the types of materials that are suitable for patrix and for matrix individually. Purpose of this study. The aim of this study was to select a proper clinical attachment system for a successful treatment as well as patient satisfaction. Methods. Retention and abrasion of 14 commercial attachments were measured during 15,000 removes. Results. A retentive part (matrix) which requires elasticity has to be made of gold while the patrix part which does not require elasticity has to be made of titanium. This gold matrix / titanium patrix combination showed the most retentive force and the least retention loss.

반복 하중이 Full veneer crown의 유지력에 미치는 영향에 관한 연구 (THE EFFECT OF CYCLIC LOADING ON THE RETENTIVE STRENGTH OF FULL VENEER CROWNS)

  • 김기연;이선형;정헌영;양재호;허성주
    • 대한치과보철학회지
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    • 제38권5호
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    • pp.583-594
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    • 2000
  • Dislodgement of a crown or extension bridge and the loosening of a retainer of a bridge is a serious clinical problem in fixed restoration. Generally these problems are considered to be associated with deformation of the restoration. During biting, the restoration is subjected to complex forces and deforms considerably within the limit of its elasticity. Deformation of the restoration under the occlusal force induces excessive stress in the cement film, which then leads to the cement fracture. Such a fracture may eventually cause loss of the restoration. Because most of the past retention tests for full veneer crown were done without fatigue loading, they were not exactly simulating intraoral environment. And the purpose of this study was to evaluate the effect of cyclic cantilever loading on the retentive strength of full veneer crowns depending on different type of cements and taper of prepared abutment. Steel dies with $8^{\circ}\;or\;16^{\circ}$ convergence angle were fabricated through milling and crowns with the same method. These dies and crowns were divided into 8 groups. Group 1 : $16^{\circ}$ taper die, cementation with zinc phosphate cement, without loading Group 2 : $16^{\circ}$ taper die, cementation with zinc phosphate cement, with loading Group 3 : $8^{\circ}$ taper die, cementation with zinc phosphate cement, without loading Group 4 : $8^{\circ}$ taper die, cementation with zinc phosphate cement, with loading Group 5 : $16^{\circ}$ taper die, cementation with Panavia 21, without loading Group 6 : $16^{\circ}$ taper die, cementation with Panavia 21, with loading Group 7 : $8^{\circ}$ taper die, cementation with Panavia 21 without loading Group 8 : $8^{\circ}$ taper die, cementation with Panavia 21, with loading After checking the fit of die and crown, the luting surface of dies and inner surface of crowns were air-abraded for 10 seconds. The crowns were cemented to the dies, with cements mixed according to the manufacturer's recommendations. A static load of 5kg was then applied for 10 minutes with static loading device. Twenty-four hours later, group 1, 3, 5, 7 were only thermocycled, group 2, 4, 6, 8 were subjected to cyclic loading after thermocycling. Retentive tests were performed on the Instron machine. From the finding of this study, the following conclusions were obtained 1. Panavia 21 showed significantly higher retentive strength than zinc phosphate cement for all groups (p<0.05). 2. There was a significant difference in the retentive strength between $8^{\circ}\;and\;16^{\circ}$ taper for zinc phosphate cement(p<0.05), but no significant difference for Panavia 21 (p>0.05). 3. Cyclic loading significantly decreased the retentive strength for all groups(p<0.05). 4. For zinc phosphate cement, there was 35% reduction of the retentive strength after loading in the $16^{\circ}$ taper die, 25% in the $8^{\circ}$ taper die, and for Panavia 21, 21% in the $16^{\circ}$ taper die, 18% in the $8^{\circ}$ taper die.

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의치인상채득(義齒印象採得)에 관련(關聯)되는 응용물리학(應用物理學) (Applied physics in relation to Denture Impression Making)

  • 김영수
    • 대한치과보철학회지
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    • 제9권1호
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    • pp.79-83
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    • 1969
  • 1) 가능(可能)한한 조직(組織)이 변형(變形)되지 않아야 한다. 2) Atmospheric pressure를 이용(利用)하기 위(爲)하여 peripheral border 에 있어서의 조직변형(組織變形)이 필요(必要)한 경과(境過)는 그 정도(程度)가 eiastic force가 retentive force 보다 크지 않도록 최소한(最小限)으로 해야 한다. 3) Denture base와 조직(組織)의 원형간(原形間)에는 접촉(接觸)이 밀접(密接)해야 한다. 그래야 saliva의 film 균일(均一)하고 얇게 될 수 있다. 4) Atmospheric pressure는 denture의 retention과 중요(重要)한 연관성이 있으므로 physiologic seal area를 형성(形成)해 주는 것이 유리(有利)하다. 5) Ridge의 형태(形態)도 denture의 retention 대(對)한 하나의 중요(重要)한 인자(因子)이다. 6) Denture에 의(依)해서 피개(被蓋)되는 면적(面積)은 retention에 관계(關係)되는 한 인자(因子)로써 피개면적(被蓋面積)이 클수록 유지력(維持力)이 커진다. 7) Saliva의 viscosity도 retention의 한 인자(因子)가 된다. 8) Friction은 retention의 한 인자(因子)가 될수는 있으나 병인적(病因的)인 증상(症狀)을 유발(誘發)할수 있으므로 이용(利用)해서는 않된다.

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관절원판 절제술후 중간삽입물 고정에 피브린 접착제의 응용 (APPLICATION OF FIBRIN ADHESIVE IN DISK REPLACEMENT AFTER MENISCECTOMY)

  • 정훈;김형근;김영수;유기준;안병근
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제14권3호
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    • pp.175-184
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    • 1992
  • Meniscectomy is indicated for the internal derangement of disk with perforation and gross morphological changes, nonreactive to conservative treatment procedures. After the meniscectomy, permanent disk replacement can be followed. Variable materials have been introduced for disk replacement. Of them, relatively harder replacing materials should have been fixed with surgical wire only. This poor fixation method provide inadequate retentive force and conclusively can be attributed to postoperative noise, poor prognosis. We tried to use biocompatible fibrin adhesive in order to obtain additional fixation force in the method above mentioned and treated two patients with the late stage of internal derangement of disk In both cases, satisfactory results were obtained.

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다양한 중합방법에 따른 악안면 보철용 폴리우레탄과 자가중합 레진 간의 결합력에 관한 연구 (A Study on the Adhesiveness between Polyurethane Sheet for Maxillofacial Prostheses and Autopolymerizing Acrylic Resin in Various Polymerization Methods)

  • 김두열;조인호
    • 구강회복응용과학지
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    • 제16권2호
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    • pp.123-132
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    • 2000
  • The field of maxillofacial prosthetics is concerned with the prosthetic reconstruction of missing head and neck tissue. Currently, facial prostheses are usually applied in cases of defects caused by the surgical removal of tumors or congenital defects. While silicone has been most widely used for the reconstruction of missing maxillofacial defects, it does not have ideal physical properties. Therefore, bonding a thin polyurethane sheet to silicone prostheses was recommended. In this case skin adhesives were used for the retention of maxillofacial prostheses. But retention of devices has always been problematic. The contributions of implants can be made to solve these problems. Implants have reduced the need for adhesive use, simplifying cleaning procedures and thus extending the life of the prostheses. For implant-retained prostheses, retentive matrix is necessary to hold attachments and/or magnets. The retentive matrix is usually fabricated with autopolymerizing acrylic resin or visible light- polymerized resin. The purpose of this study was to compare the adhesion-in-peel force of silicone adhesive to autopolymerizing acrylic resin and polyurethane sheet with two different surface textures : pumice polish only or retention groove, and three surface primers : Dow corning 1205 primer or Dow corning S-2260 primer or FactorII A-304 primer, and two polymerization methods : room temperature or dry heat oven. The t-peel bond strength of specimens was determined as described in ASTM Standard D1876-72. The results were statistically analyzed using the ANOVA test, multiple range test and t-test The results were as follows. 1. The t-peel bond strength of A-304 primer was the highest and statistically higher than that of S-2260(p<0.05). 2. The t-peel bond strength of specimens with retention groove was statistically higher than that of specimens polished with pumice(p<0.05). 3. The t-peel bond strength of specimens polymerized in dry heat oven was statistically higher than that of specimens in room temperature(p<0.01).

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짧은 티타늄 지대주에 합착된 CAD/CAM 금속 코핑의 시멘트 종류에 따른 유지력 비교 (Retention of CAD/CAM Metal Copings Cemented on Short Titanium Abutments with Different Cements)

  • 김효정;송은영;윤지영;이시호;이용근;오남식
    • 구강회복응용과학지
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    • 제28권2호
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    • pp.119-126
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    • 2012
  • 시멘트 유지 임플란트 지지 수복물은 치과 치료에 일상적으로 사용된다. 임플란트와 지대주 나사연결의 안정적인 견고함과 골유합 임플란트의 높은 생존율로 인해 높은 강도를 가진 시멘트의 사용이 점차 늘어나고 있다. 그러나 CAD/CAM을 이용하여 제작한 금속 코핑의 유지력에 대해 이용할 수 있는 임상 자료가 없다. 네 종류의 시멘트를 이용하여 티타늄 지대주와 CAD/CAM을 이용하여 제작한 금속 코핑의 유지력을 평가하는 것과 시멘트 유지력에 대한 sandblasting의 효과를 알아보고자 함이다. 40개의 티타늄 지대주 블록(Innovium, 세라젬바이오시스, 대한민국)을 제작하여 네 그룹으로 나누었다. 40개의 금속 코핑을 CAD/CAM을 이용하여 제작하고 금속 코핑의 교합면 상방부에 유지력 테스트를 위해 구멍을 형성하였다. 네 종류의 시멘트는 Fujicem(Fuji, Japan), Maxcem Elite(Kerr, USA), Panavia F2.0(Kurarary, Japan), Superbond C&B(Sunmedical, Japan)이다. 금속 코핑과 티타늄 지대주를 제조사의 지시대로 시멘트 혼합하여 합착하고 100% 습도 하에 37도에서 24시간 동안 보관 후 유지력 테스트하였다. 유지 실패가 발생하는 힘을 newton으로 기록하고 실패의 양상 또한 기록하였다. 유지력의 평균과 표준 편차를 ANOVA와 Paired t-test 로 통계분석하였다. Panavia F2.0이 Fujicem과 Maxcem Elite보다 통계적으로 유의하게 높은 유지력을 보였다(p<0.05). Sandblasting이 모든 시멘트에서 유의하게 유지력을 증가시켰다(p<0.05). 유지력 실패의 양상은 대부분의 시멘트가 금속 코핑 내부에 남아있는 접착성 실패였다. 본 연구의 한계 내에서 Panavia F2.0이 Fujicem이나 Maxcem Elite보다 통계적으로 유의하게 큰 유지력을 보였고(p<0.05), Fujicem과 Maxcem Elite는 유지력의 차이를 보이지 않았다. Sandblasting처리는 모든 실험군에서 유지력의 향상을 보였다. 따라서 임플란트 지대주에 합착된 금속 코핑의 유지력은 표면 거칠기와 시멘트의 종류에 영향을 받는다.

수종수복용 Pin의 유지력에 관한 실험적 연구 (AN EXPERIMENTAL STUDY ON RETENTIVE PROPERTIES OF VARIOUS PINS IN DENTIM)

  • 이명종
    • 대한치과의사협회지
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    • 제15권11호
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    • pp.763-766
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    • 1977
  • The Purpose of this study was to observe force required to remove some kinds of pin from dentin. The teeth were embedded within a resin cylinder and the occlusal surface was sectioned at a right angle to the axis of the cylinder to expose dentin surface. Thread mate system pin (minim and regular), friction Iocked pin and cemented pin were tested Pin holes were drilled by handpiece and depths of pin holes were tested 1,2 and 3mm. After insertion of the pins into pinhole, tensile loading was performed on the Instron testing machine at the speed of 0.5 inch/min. Results were follewed: 1. In retention, the cemented pins are the least, the friction locked pins intermediate and the self threading pins the greatest in all pins. In self threading pins, regalar pin has greater retention than minim pin 2. The deeper the depth of the pin hole is, the more the retention of the pin increases.

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Effect of hemispherical dimples at titanium implant abutments for the retention of cemented crowns

  • Jung-Hoon Choi;Seong-Joo Heo;Jai-Young Koak;Seong-Kyun Kim;Ji-Man Park;Jin-Soo Ahn
    • The Journal of Advanced Prosthodontics
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    • 제15권2호
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    • pp.63-71
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    • 2023
  • PURPOSE. The aim of this study was to assess the effect of hemispherical dimple structures on the retention of cobalt-chromium (Co-Cr) crowns cemented to titanium abutments, with different heights and numbers of dimples on the axial walls. MATERIALS AND METHODS. 3.0-mm and 6.0-mm abutments (N = 180) and Co-Cr crowns were prepared. The experimental groups were divided into two and four dimple groups. The crowns were cemented by TempBond and PANAVIA F 2.0 cements. The retention forces were measured after thermal treatments. A two-way Analysis of Variance (ANOVA) and post-hoc Tukey HSD test were conducted to analyze change in retention forces by use of dimples between groups, as well as t test for the effect of abutment height change (α = .05). RESULTS. Results of the two-way ANOVA showed a statistically significant difference in retention force due to the use of dimples, regardless of the types of cements used (P < .001). A significantly higher mean retention forces were observed in the groups with dimples than in the control group, using the post hoc Tukey HSD test (P < .001). Results of t test displayed a statistically significant increase in the retention force with 6.0-mm abutments compared with 3.0-mm abutments (P < .001). The groups without dimples revealed adhesive failure of cements, while the groups with dimples showed mixed failure of cements. CONCLUSION. Use of hemispherical dimples was effective for increasing retention forces of cemented crowns.

Prosthetic reconstruction with an obturator using swing-lock attachment for a patient underwent maxillectomy: A clinical report

  • Seong, Dong-Jae;Hong, Seoung-Jin;Ha, Seung-Ryong;Hong, Young-Gi;Kim, Hyo-Won
    • The Journal of Advanced Prosthodontics
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    • 제8권5호
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    • pp.411-416
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    • 2016
  • Patients who underwent resection of maxilla due to benign or malignant tumor, or accident will have defect in palatal area. They get retention, support and stability from remaining tissues which are hardly optimal. The advantage of swing-lock attachment design is having multiple contacts on labial and lingual side of the abutment teeth by retentive strut and palatal bracing component. Because the force is distributed equally to abutment teeth, abutment teeth of poor prognosis can be benefited from it. It is also more advantageous to cover soft tissue defects which are hard to reach with conventional prosthesis. A 56-year-old female patient who had undergone a maxillectomy due to malignant melanoma complaining of loose and unstable surgical obturator. Surveyed crowns were placed on #12, 26, and 27. Teeth #11, 21, 22, and 23 had lingual rest seat and #24 had mesial rest seat to improve stability and support of the obturator. This clinical report presents the prosthetic management of a patient treated with obturator on the maxilla using swing-lock attachment to the remaining teeth.

시멘트 유지형 임플란트 지대주의 높이와 축면경사도가 보철물의 유지력에 미치는 영향 (Effect of different abutment height and convergence taper on the retention of crowns cemented onto implant-supported prostheses)

  • 변태희;김부섭;정인성
    • 대한치과기공학회지
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    • 제30권1호
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    • pp.57-63
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    • 2008
  • The purpose of this study was to ascertain the effect of different abutment height and different taper of abutment on retention force of cemented implant-supported prostheses. Test specimens consisted of different abutment height group(3mm, 4mm, 5mm, 6mm, 7mm) and different taper(degrees) abutment group($4^{\circ},\;5^{\circ},\;6^{\circ},\;7^{\circ},\;8^{\circ}$). The surfaces of abutments and crowns were manufactured and finished by automatic lathe(CNC). Luting cement(Tokuso Ionomer) was prepared according to the manufacturer's instruction. And the cylinders were sealed onto the abutments and loaded in compression at 5kg for 10minutes. Excess cement was removed from the abutment-cylinder junction and the specimens were stored at room temparature for 24 hours. Specimens were tested in tension using a universal testing machine. Within the limits of this study, the following conclusions were drawn: 1. The increase in abutment height result in improvement in retention strength(P<0.05). 2. The increase in taper of abutment result in decrease in retention strength(P<0.05). 3. The decrease in abutment height result in decrease in retention strength, besides has a significantly lower retention strength at 3mm abutment height. 4. The increase in taper of abutment result in decrease in retention strength, besides has a significantly lower retention strength at $7^{\circ}$ abutment.

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