• 대한치과보철학회지
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• 제41권2호
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• pp.223-231
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• 2003

Statement of problem : Little is known about the effect of a counter-torque device and the internal hexagon of abutment on the tightening torque transmitted to the implant. Purpose : The purpose of this study was to examine the effect of a counter-torque device and the internal hexagon of abutment on the tightening torque transmitted to the implant. Material and Methods : In this study, three types of abutment were used, (1) two-piece conical abutment with hexagon, (2) two-piece conical abutment without hexagon, and (3) one-piece conical abutment without hexagon. The experimental groups were divided into five groups according to the type of abutment and the usage of a counter-torque device. Group I : two-piece conical abutment with internal hexagon was tightened without the use of a counter-torque device. Group II : two-piece conical abutment without internal hexagon was tightened without the use of a counter-torque device. Group III : one-piece conical abutment without internal hexagon was tightened without the use of a counter-torque device. Group IV : two-piece conical abutment with internal hexagon was tightened with the use of a counter-torque device Group V : two-piece conical abutment without internal hexagon was tightened with the use of a counter-torque device. Abutments were tightened 20Ncm torque with the use of manual torque wrench and then torque values were measured by torque-gauge. After the measurement of torque values, all groups were loosened with the use of manual torque wrench and then detorque values were measured by torque-gauge. Results : The results were as follows. 1. There were no differences in torque values among three types of abutment. 2. Regardless of the existence of the internal hexagon of abutment, a counter-torque device decreased the tightening torque transmitted to the implant about 92% 3. In group III showed the highest detorque value, however there were no differences among group I, II, IV and V. Conclusion : Within the limitations of this study, it was concluded that the internal hexagon of abutment has no effect on the tightening torque transmitted to the implant and the detorque value of abutment screw. The use of a counter-torque device is essential to prevent microfracture on the implant-bone interface but has no effect on preload.

• The Journal of Advanced Prosthodontics
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• 제6권6호
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• pp.491-497
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• 2014

PURPOSE. This study evaluated the influence of abutment materials on the stability of the implant-abutment joint in internal conical connection type implant systems. MATERIALS AND METHODS. Internal conical connection type implants, cement-retained abutments, and tungsten carbide-coated abutment screws were used. The abutments were fabricated with commercially pure grade 3 titanium (group T3), commercially pure grade 4 titanium (group T4), or Ti-6Al-4V (group TA) (n=5, each). In order to assess the amount of settlement after abutment fixation, a 30-Ncm tightening torque was applied, then the change in length before and after tightening the abutment screw was measured, and the preload exerted was recorded. The compressive bending strength was measured under the ISO14801 conditions. In order to determine whether there were significant changes in settlement, preload, and compressive bending strength before and after abutment fixation depending on abutment materials, one-way ANOVA and Tukey's HSD post-hoc test was performed. RESULTS. Group TA exhibited the smallest mean change in the combined length of the implant and abutment before and after fixation, and no difference was observed between groups T3 and T4 (P>.05). Group TA exhibited the highest preload and compressive bending strength values, followed by T4, then T3 (P<.001). CONCLUSION. The abutment material can influence the stability of the interface in internal conical connection type implant systems. The strength of the abutment material was inversely correlated with settlement, and positively correlated with compressive bending strength. Preload was inversely proportional to the frictional coefficient of the abutment material.

• 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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• 제40권1호
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• pp.30-41
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• 2002

This study was to evaluate the fabrication method and marginal adaptation of the conical inner crown fabricated with CAD/CAM. The informations on abutment teeth were transferred to a computer with a micro contact digitizer, which had a $50{\mu}m$ accuracy on the master die. A conical inner crown was designed on a computer and a real crown was machined based on this design using CAM. The marginal fit of a computer-machined conical inner crown was assessed using electron microscopy Measurement of the marginal gap between the conical inner crown and the abutment was performed on four different locations (mesial, distal, buccal, and lingual surfaces) of the finish line. The evaluation was based on 10 test specimens. The results were as follow. 1 The mean marginal gap between the conical inner crown and abutment tooth was $83.2{\pm}43{\mu}m$, 28.9% of the specimen showed marginal gap over $100{\mu}m$. 2. The fabrication method using CATRS and CAM provided clinically acceptable marginal fitness compared to conventional casting method (P<0.05).

• 대한치과보철학회지
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• 제41권4호
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• pp.393-404
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• 2003

Statement of problem. Higher incidence of prosthetic complications such as screw loosening, screw fracture has been reported for posterior single tooth implant. So, there is ongoing research regarding stability of implant-abutment interface. One of those research is increasing the implant diameter and prosthetic table width to improve joint stability. In another part of this research, internal conical type implant-abutment interface was developed and reported joint strength is higher than traditional external hex interface. Purpose. The purpose of this study is to compare stress distribution in single molar implant between external hex butt joint implant and internal conical joint implant when increasing the implant diameter and prosthetic table width : 4mm diameter, 5mm diameter, 5mm diameter/6mm prosthetic table width. Material and method. Non-linear finite element models were created and the 3-dimensional finite element analysis was performed to see the distribution of stress when 300N static loading was applied to model at $0^{\circ},\;15^{\circ},\;30^{\circ}$ off-axis angle. Results. The following results were obtained : 1. Internal conical joint showed lower tensile stress value than that of external hex butt joint. 2. When off-axis loading was applied, internal conical joint showed more effective stress distribution than external hex butt joint. 3. External hex butt joint showed lower tensile stress value when the implant diameter was increased. 4. Internal conical joint showed lower tensile stress value than external hex butt joint when the implant diameter was increased. 5. Both of these joint mechanism showed lower tensile stress value when the prosthetic table width was increased. Conclusion. Internal conical joint showed more effective stress distribution than external hex joint. Increasing implant diameter showed more effective stress distribution than increasing prosthetic table width.

• 구강회복응용과학지
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• 제24권1호
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• pp.77-89
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• 2008

이 연구의 목적은 원추형 내측 연결 임플랜트 시스템에서 하중조건에 따른 지대주의 침하 및 적합도를 평가하는 것이다. 본 연구에서는 내부 원추형 연결방식의 Alloden implant system (Nei Corp. Korea)의 고정체와 2종류(conventional, FDI)의 지대주를 사용하였다. 임상에서 Alloden 임플랜트는 지대주와 고정체 연결시 처음에 손으로 지긋이 눌러 고정시킨 후 mallet을 이용하여 약 3회정도 타격을 가하여 고정한다. 이때 타격시의 정확한 힘을 측정하여 각 실험군에 적용시켰다. 적용 횟수는 손가락으로 누르는 힘을 1회, mallet으로 타격하는 힘을 3회, 저작력으로 가정한 20kg의 힘을 지대주의 침하가 생기지 않을때까지 각각의 표본에 적용하였다. 그 후 각 단계에 대한 지대주의 침하량을 Vernier caliper를 이용하여 측정하였다. 임플랜트는 불포화 폴리에스터(Epovia, Cray Valley Inc. Korea)에 매몰하여 중합시켰고 모든 표본을 절삭한 후 연마하여 주사전자현미경을 통하여 분석, 평가하였다.

• 구강회복응용과학지
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• 제24권3호
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• pp.269-281
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• 2008

골유착성 임플란트 보철물에서 피로나 과하중에 의해 보철유지 나사나 지대주 나사의 파절, 보철물의 파절, 또는 고정체의 파절 등과 같은 기계적 강도와 연관된 문제점이 발생할 가능성이 높다. 임플란트 시스템의 기계적인 강도에 영향을 주는 요소에는 고정체와 나사의 직경, 재료적 특성, 연결부 디자인, 지대주 디자인 등이 있으며, 이 중 임플란트 고정체와 지대주간의 연결부 디자인은 임플란트 시스템의 기계적인 연결상태와 연결부 안정성을 결정하는 주요소이다. 대부분의 기계적 강도에 관한 연구에서처럼 단일하중에 의한 압축굽힘강도나, 단기적인 반복하중 후의 결과만을 평가하여 임플란트 시스템의 장기적인 안정성을 예측하기에는 한계가 있다. 연구 목적: 이에 본 연구에서는 external butt joint와 internal conical joint를 갖는 임플란트 시스템(오스템사)의 연결부 디자인에서 각각 다른 두 가지 지대주를 사용하여, 연결부 및 지대주 디자인이 기계적 강도에 미치는 영향을 압축굽힘강도는 물론 내구성한계를 측정하여 알아보고자 하였다. 연구 재료 및 방법: External butt joint인 US II에서는 통상적인 UCLA 지대주 형태의 Cemented abutment(BJT)와 굽힘 저항성을 증가시키기 위해 나사 두부가 지대주 상단에 위치하도록 설계된 Safe abutment(BJS)를, internal conical joint인 SS II에서는 one-piece형의 Solid abutment(CJO)와 two-piece형의 ComOcta abutment(CJT)를 지대주로 사용하였다. ISO 규정을 참고하여 단일 임플란트, 변연골 흡수, 그리고 $30^{\circ}$ 경사하중 조건에서 압축굽힘강도와 내구성한계를 측정하였고 실패 양상을 관찰한 결과 다음과 같은 결론을 얻었다. 결과 및 결론: 1. 압축굽힘강도는 BJS군(1392.0N), CJO군(1261.8N), BJT군(1153.2N), 그리고 CJT군(1110.2N) 순으로 낮아졌으며(P<.05), CJT군과 BJT군 사이에는 차이가 없었다(P>.05) 2. 내구성한계는 CJO군(600N), CJT군(453N), BJS군(360N) 그리고 BJT군(300N) 순으로 낮아졌다. 3. 압축굽힘강도는 연결부 디자인 또는 지대주 디자인에 따라 차이를 보였으며, 내구성한계에 있어서는 연결부 디자인이 더 주된 요소로 작용하였다.

• 구강회복응용과학지
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• 제36권2호
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• pp.95-103
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• 2020

목적: 본 연구의 목적은 내부연결 원추형 임플란트의 육각구조 유무가 임플란트 지대주 장축변위와 임플란트 지대주 나사의 풀림토크에 미치는 영향을 평가하고자 하였다. 연구 재료 및 방법: 내부연결 원추형 임플란트를 육각구조를 가진 지대주 그룹(HEX)과 육각구조를 갖지 않는 지대주 그룹(CON)으로 나누고 각 그룹 당 10쌍의 시편을 체결하였다. 지대주 나사를 30 Ncm 조임회전력을 가하여 체결한 뒤 장축변위 및 풀림토크값을 측정하고 250 N 수직적 반복하중을 100,000회 가한 뒤 장축변위 및 풀림토크값을 측정하였다. 각 단계마다 디지털 마이크로미터를 이용하여 임플란트 직경과 수직적 높이를 측정하였고 전자 토크게이지를 이용하여 풀림토크값을 측정하였다. 각 군간의 값의 유의차를 확인하기 위하여 독립 표본 T 검정을 이용하여 통계분석하였다(α = 0.05). 결과: HEX 군은 조임회전력을 가한 뒤 유의하게 높은 장축변위를 나타내였다(P < 0.05). HEX 군과 CON 군은 수직적 반복하중 후 장축변위에 유의한 차이를 보이지 않았다(P = 0.052). HEX 군과 CON 군은 수직적 반복하중 전, 후 풀림토크값 모두 유의한 차이를 보이지 않았다(P = 0.057 and P = 0.138). 모든 그룹에서 반복하중 후 풀림토크값 상실율이 증가하였다(P < 0.05). 결론: 내부연결 원추형 임플란트에서 육각구조를 가진 경우 장축 변위가 더 컸으며, 그 외의 연결부 안정성은 유사하였다. 모든 그룹에서 반복하중 후 풀림토크값 상실율이 증가하였다.

• 대한치과의사협회지
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• 제53권5호
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• pp.360-367
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• 2015

Purpose : The purpose of this study was to evaluate the effect of amount of cantilever in intra-crown according to implant fixture position on mechanical strength of internal conical joint type implant. Materials and Methods : Internal conical joint type implant fixture, abutment screw, abutment was connected and gold alloy prostheses were fabricated and cemented on abutment. For fatigue fracture test, the specimens were loaded to the 350 N, 2,000,000 cycle on 3, 4, 5, and 6 mm off-center of gold alloy prostheses. The fracture pattern of implant component was observed. Results : No fatigue fracture found on 3 and 4 mm group. But initial crack pattern found on 3 specimens of 4 mm group. Fatigue fracture found on all specimens of 5 mm group. But complete fracture was not observed. One specimen of 6 mm group fracture completely. Implant fixture fracture wax not observed. Conclusion : The mechanical failure of implant prostheses increased with the loading area farther from center of implant fixture. To reduce mechanical problem of internal joint type implant, surgical and prosthetic consideration is needed.

• 구강회복응용과학지
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• 제30권3호
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• pp.206-214
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• 2014

목적: 내부 원추형 연결형태 임플란트에서 지대주 나사의 좌면각도가 연결부의 기계적 안정성에 미치는 영향을 알아보기 위함이다. 연구 재료 및 방법: 원추형 연결구조 티타늄 임플란트와 시멘트 유지형 지대주, 텅스텐 카바이드 코팅된 티타늄 합금 지대주 나사를 사용하였다. 좌면각도가 $45^{\circ}$와 $90^{\circ}$를 갖는 지대주와 지대주 나사를 제작하여 30 Ncm 조임회전력으로 지대주를 체결한 후 하중을 가하고 체결 및 하중 부여에 따른 침하량을 측정하였다(n = 5). 유압식 피로시험기에 임플란트를 고정하고 스테인리스 스틸 금속관을 지대주에 합착하였다. 이 후 반복 하중을 가한 후 풀림토크 변화량을 측정하고, 압축굽힘강도와 피로강도를 측정하였다(n = 5). 결과: 지대주 침하량은 지대주나사 체결 시 가장 크게 나타났으며(P < 0.05), 나사체결과 하중부여에 따른 총 침하량은 $45^{\circ}$군보다 $90^{\circ}$군에서 더 크게 측정되었다(P < 0.05). 반복하중 부여 후 풀림 토크, 그리고 최대 압축굽힘강도와 피로강도는 통계적으로 유의한 차이를 보이지 않았다(P > 0.05). 결론: 본 실험조건하에서 지대주 나사머리의 원추형 설계가 지대주의 총 침하량을 약간 감소시키는 효과를 나타냈으나, 연결부의 전체적인 기계적 안정성에 미치는 영향은 크지 않을 것으로 판단된다.