• 한국기계가공학회지
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• 제15권2호
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• pp.97-103
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• 2016

When chewing forces are repetitively applied to a dental implant, gaps are often generated at the interface surfaces between the abutment and the fixture, which results in some deterioration, such as loosening of the fastening screw, dental retraction, and fixture fractures. To cope with such problems, a sealing-type abutment having a number of grooves along the conical-surface circumference was previously developed, and it showed better sealing performance than conventional ones. To enhance the sealing performance, a new model in which a gold ring is inserted into the top groove of the sealing-type abutment is developed in this study. In addition, a manufacturing process is developed, and performance evaluations, such as fatigue and sealing tests, are carried out. The evaluation results show that the gold-ring-inserted sealing abutment yields better performance than conventional ones.

• 대한치과보철학회지
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• 제42권2호
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• pp.192-209
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• 2004

Purpose : The purpose of this study was to evaluate the machining accuracy and consistency of implant/abutment/screw combination or internal connection type. Material and methods: In this study, each two randomly selected internal implant fixtures from ITI, 3i, Avana, Bicon, Friadent, Astra, and Paragon system were used. Each abutment was connected to the implant with 32Ncm torque value using a digital torque controller or tapping. All samples were cross-sectioned with grinder-polisher unit (Omnilap 2000 SBT Inc) after embeded in liquid unsaturated polyester (Epovia, Cray Valley Inc). Then optical microscopic and scanning electron microscopic(SEM) evaluations of the implant-abutment interfaces were conducted to assess quality of fit between the mating components. Results : 1) Generally, the geometry of the internal connection system provided for a precision fit of the implant/abutment into interface. 2) The most precision fit of the implant/abutment interface was provided in the case of Bicon System which has not screw. 3) The fit of the implant/abutment interface was usually good in the case of ITI, 3I and Avana system and the amount of fit of the implant/abutment interface was similar to each other. 4) The fit of the implant/abutment interface was usually good in the case of Friadent, Astra and Paragon system. The case of Astra system with the inclined contacting surface had the most Intimate contact among them. 5) Amount of intimate contact in the abutment screw thread to the mating fixture was larger in assembly with two-piece type which is separated screw from abutment such as Friadent, Astra and Paragon system than in that with one-piece type which is not seperated screw from abutment such as ITI, 3I and Avana system. 6) Amount of contact in the screw and the screw seat of abutment was larger in assembly of Friadent system than in asembly of Astra system of Paragon system. Conclusion: Although a little variation in machining accuracy and consistency was noted in the samples, important features of all internal connection systems were the deep, internal implant-abutment connections which provides intimate contact with the implant walls to resist micro-movement, resulting in a strong stable interface. From the results of this study, further research of the stress distribution according to the design of internal connection system will be required.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2006년도 추계학술발표회 초록집
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• pp.96-96
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• 2006

• 대한치과보철학회지
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• 제45권6호
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• pp.780-786
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• 2007

Statement of problem. The performance and maintenance of implant-supported prostheses are primarily dependent upon load transmission both at the bone-to-implant interface and within the implant-abutment-prosthesis complex. The design of the interface between components has been shown to have a profound influence on the stability of screw joints. Purpose. The Purpose of this study was to compare the strength and the fatigue resistance of 1-piece and 2-piece abutment connected to oral implant, utilizing an internal conical interface. Material and methods. Twenty $Implatium^{(R)}$ tapered implants were embedded to the top of the fixture in acrylic resin blocks. Ten $Combi^{(R)}$(1-piece) and $Dual^{(R)}$(2-piece) abutments of the same dimension were assembled to the implant, respectively. The assembled units were mounted in a testing machine. A load was applied perpendicular to the long axis of the assemblies and the loading points was at the distance of 7mm from the block surface. Half of 1-piece and 2-piece abutment-implant units were tested for the evaluation of the bending strength, and the others were cyclically loaded for the evaluation of the fatigue resistance until plastic deformation occurred. Nonparametric statistical analysis was performed for the results. Results. Mean plastic and maximum bending moment were $1,900{\pm}18Nmm,\;3,609{\pm}106Nmm$ for the 1-piece abutment, and $1,250{\pm}31Nmm,\;2,688{\pm}166Nmm$ for the 2-piece abutment, respectively. Mean cycles and standard deviation when implant-abutment joint showed a first plastic deformation were $238,610{\pm}44,891$. cycles for the 1-piece abutment and $9,476{\pm}3,541$ cycles for the 2-piece abutment. A 1-piece abutment showed significantly higher value than a 2-piece abutment in the first plastic bending moment (p<.05), maximum bending moment (p<.05) and fatigue strength (p<.05). Conclusion. Both 1-piece and 2-piece conical abutment had high strength and fatigue resistance and this suggests long-term durability without mechanical complication. However, the 1-piece conical abutment was more stable than the 2-piece conical abutment in the strength and the fatigue resistance.

• 대한치과보철학회지
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• 제60권1호
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• pp.1-8
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• 2022

목적: 본 연구는 Healing abutment case (HA case)를 이용한 Healing abutment (HA)의 효과적인 세척에 대하여 알아보고자 구강 미생물을 위상차현미경으로 관찰하였다. 대상 및 방법: 임플란트를 동일 악에 2개 이상 식립 한 32명의 환자, 총 64개의 HA (실험군 32, 대조군 32)를 선정하여 실험군은 알코올 솜으로 세척 후 HA case에 넣어 0.05% chlorhexidine 소독용액을 담은 초음파세척기에서 5분간 세척하였고, 대조군은 알코올 솜으로 세척하였다. 관찰 시기는 1차, 2차 내원 시 각 군을 세척 전 관찰하였고, 실험군은 1차 내원 시 세척 후 추가로 관찰하였다. 이 때 미생물의 양에 대하여 400배의 위상차현미경으로 관찰하였다. 결과: 1차 내원 시 각군의 구강미생물 양을 관찰한 결과 통계적 유의한 차이는 없었으며, 성별, 상·하악, 협·설측에 따른 차이도 없었다. 치은연상, 연하에 따른 구강미생물 양은 통계적으로 유의한 차이를 보였으며(P < .05), 실험군 세척 전·후 비교에서도 유의한 차이를 보였다(P < .05). 2차 내원 시 각 군별 비교에서 구강미생물 양의 유의한 차이를 보였다(P < .05). 결론: Healing abutment case를 이용한 healing abutment의 세척은 단순 알코올 솜 세척에 비해 효과가 있는 것으로 사료된다.

• 대한치과보철학회지
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• 제29권2호
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• pp.129-145
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• 1991

The purpose of this study was to analyze the stresses and displacements of various esthetic restorations and abutment teeth. The finite element models of central incisor were divided into four groups according to the types of restoration. Three load cases were applied; 1) 45 degrees on the incisal edge, 2) horizontal force on the labial surface, and 3) 26 degrees diagonally on the lingual surface. Material property, geometry, and load conditions of each model were inputed to the two dimensional finite element program and stresses and displacements were analyzed. Results were as follows; 1. In the cases of porcelain fused gold ann and porcelain laminate venner, stresses were equally distributed in supporting abutment tooth. 2. The metal coping of porcelain fused gold u and collarless porcelain fused gold crown functioned as a good stress distributor. 3. When the horizontal load applied, the highest tensile and compressive stresses were seen in the cervical margin of restoration and the dentin of the abutment tooth. 4. The highest displacement of restoration was seen when load was applied at an mee of 26 degrees diagonally in lingual surface of tooth in centric occlusion. 5. The influence of loading direction on the stresses and displacements in the restoration was greater than that of various design. 6. The possibility of fracture was highest in porcelain jacket crown.

• 대한치과보철학회지
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• 제44권1호
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• pp.85-102
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• 2006

Statement of problem: Currently, there are some 20 different geometric variations in implant/abutment interface available. The geometry is important because it is one of the primary determinants of joint strength, joint stability, locational and rotational stability. Purpose: As the effects of the various implant-abutment connections and the prosthesis height variation on stress distribution are not yet examined this study is to focus on the different types of implant-abutment connection and the prosthesis height using three dimensional finite element analysis. Material and method. The models were constructed with ITI, 3i TG, Bicon, Frialit-2 fixtures and solid abutment, TG post, Bicon post, EstheticBase abutment respectively. And the super structures were constructed as mandibular second premolar shapes with 8.5 mm, 11 mm, 13.5 mm of crown height. In each model, 244 N of vertical load and 244 N of $30^{\circ}$ oblique load were placed on the central pit of an occlusal surface. von Mises stresses were recorded and compared in the crowns, abutments, fixtures. Results: 1. Under the oblique loading, von Mises stresses were larger in the crown, abutment, fixture compared to the vertical loading condition. 2. The stresses were increased proportionally to the crown height under oblique loading but showed little differences with three different crown heights under vertical loading. 3. In the crown, the highest stress areas were loading points under vertical loading, and the finish lines under oblique loading. 4. Under the oblique loading, the higher stresses were located in the fixture/abutment interface of the Bicon and Frialit-2 systems compared to the ITI and TG systems. Conclusions: The stress distribution patterns of each implant-abutment system had difference among them and adequate crown height/implant ratio was important to reduce the stresses around the implants.

• 구강회복응용과학지
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• 제25권4호
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• pp.349-360
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• 2009

목적: 임플란트 보철 수복에서 심미적 요구도가 증진되면서 최근에는 고강도, 고인성을 지니면서 생체적합성 우수하고 치아의 색과 조화로운 지르코니아 지대주의 사용이 증가하는 추세이다. 몇몇 임상보고를 통해 지르코니아 지대주의 우수한 주위조직 반응과 단기간의 성공적인 결과가 보고 되었으나, 장기간의 안정성을 평가하는 기계적 강도에 관한 연구는 미흡한 실정이다. 이에 본 연구에서는 직경, 각도, 연결방식이 상이한 임플란트 고정체 - 지르코니아 지대주의 단순 파절강도와 반복하중에 의한 피로한계 측정을 통해 지르코니아 지대주의 기계적 안정성을 평가해 보고자 하였다. 재료와 방법: ISO규정에 따라 지르코니아 지대주-고정체를 변연골이 3mm 흡수된 조건에서 $30^{\circ}$경사하중으로 압축굽힘강도를 측정하고, 그 값의 80%를 최대하중으로 10%를 최소하중으로 하여 10Hz의 sine형 반복하중을 $5{\times}10^6$ 주기를 초과하는 조건의 내구성한계를 측정하였다. 지르코니아 지대주로는 regular diameter를 가지면서 external butt joint의 straight 지대주와 $17^{\circ}$ angled 지대주, 그리고 narrow diameter 이면서 external butt joint의 straight 지대주와 internal conical joint의 straight 지대주를 사용하였다. 압축굽힘강도 값을 일원분산분석과 사후검정으로 검증하였으며, 피로파절면을 전자주사현미경을 통해 관찰했다. 결과: 압축굽힘강도는 최소 927N 이상으로, 직경의 차이에 따른 유의한 차이를 보였으며( P<.05), 내구성 한계는 503N에서 868N까지의 번위를 보였다. 결론: 지르코니아 지대주는 구강내 기능하중을 견딜수 있는 적절한 기계적 강도를 가지는 것으로 판단된다.

• 대한치과보철학회지
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• 제40권3호
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• pp.275-286
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• 2002

Statement of problem. Surface alteration of the implant screws after function may be associated with mechanical failure. Theses metal fatigue appears to be the most common cause of structural failure. Purpose. The purpose of this study was to evaluate surface alteration of the implant screws after function through the examination of used and unused implant screws in SEM(scanning electron microscope). Materials and methods. In this study, abutment screws(Steri-oss, 3i), gold retaining screw(3i) and titanium retaining screw(3i) were retrieved from patients. New, unused abutment and retaining screws were prepared for control group. Each of the old, used screws was retrieved with a screwdriver. And retrieved implant complex of Steri-oss system was prepared for this study. Then, SEM investigation and EDS analysis of abutment and retaining screws were performed. And SEM investigation of cross-sectioned sample of retrieved implant complex was performed. Results. In the case of new, unused implant screws, as maunfactured circumferential grooves are regularly examined and screw thread are sharply remained. Before ultrasonic cleansing of old, used implant screw, a lot of accumulation and corrosion products were existed. After ultrasonic cleansing of old, used implant screws, circumferential grooves as examined before function were randomly deepened and scratches increased. Also, dull screw thread was examined. More surface alterations after function were examined in titanium screw than gold screw. And more surface alteration was examined when retrieved with driver than retrieved without driver. Conclusions. These surface alteration after function may result in the screw instability. Regularly cleansing and exchange of screws was recommended. We recommend the use of gold screw rather than titanium screw, and careful manipulation of the driver.

• 구강회복응용과학지
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• 제26권4호
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• pp.389-403
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• 2010

이전부터 사용된 티타늄, 금합금 지대주 및 최근 사용이 급증한 지르코니아 지대주와 임플란트의 계면에 대한 비교 연구와 동적하중이 계면에 미치는 영향에 관한 연구가 많지 않은 실정이다. 본 연구에서 지대주 종류와 동적 하중에 따른 미세간극의 차이를 주사전자현미경 분석을 통하여 비교평가 하였다. USII ${\phi}3.75{\times}11.5mm$ (Osstem Co., Seoul, Korea) 티타늄 임플란트에 티타늄 지대주, 지르코니아 지대주, 주조 금합금 (UCLA plastic) 지대주를 각 군당 7개씩, 30Ncm의 조임회전력으로 연결하였다. 25-250N의 sine형 동적하중을 장축 방향에서 $30^{\circ}$ 경사로 $10^5$회 시행하였다. 하중 전후에 계면의 미세간극을 순측, 구개측, 근심측, 원심측 부위에서 측정하였고, 그 결과 동적 하중으로 인한 통계적 유의성은 없었다. 지대주 종류에 따른 미세간극을 비교한 결과, 동적하중 시행 전후 모두 UCLA 군과 티타늄 군, UCLA 군과 지르코니아 군 사이에 통계적으로 유의한 차이를 보였다(p<0.05). 티타늄 군과 지르코니아 군 사이에는 유의한 차이를 보이지 않았다. UCLA 지대주는 정밀 연삭된 티타늄, 지르코니아 지대주 보다 더 큰 미세간극을 보였고 $10^5$회 동적하중은 미세간극에 영향을 미치지 않았다.