• 대한치과보철학회지
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• 제46권6호
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• pp.628-633
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• 2008

STATEMENT OF PROBLEM: The application of a simple, clinically applicable noninvasive test to assess implant stability are considered highly desirable. So far there is still a controversy about correlation of various tests and implant stability. PURPOSE: In order to assess implant stability, the development of a new method is critical. It's possible to assess implant stability by calculating energy and angular momentum during implant installation. The purpose of this study is to evaluate the correlation of energy and implant stability. MATERIAL AND METHODS: Twenty three implants were installed in two different types of pig bone. Type I bone was retrieved from the distal aspect of the rib, with more cortical bone. Type II bone came from a more proximal region with less cortical components and a higher content of bone marrow and spongeous trabeculae. Insertion torque, removal torque, ISQ values and angular momentum and energy were measured. Pearson Correlation test was done to analyze the relation between RFA, maximum insertion torque, mean insertion torque, bone type, energy and removal torque. RESULTS: Type I bone showed higher removal torque than type II bone. Energy value was significantly correlated with maximum insertion torque and mean insertion torque. RFA values were related with insertion torques but the significance was lower than Energy value. CONCLUSION: Within the limitation of this study energy values were considered clinically predictable method to measure the implant stability.

• Journal of Yeungnam Medical Science
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• 제36권1호
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• pp.43-49
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• 2019

Background: In the osseointegration of dental implants, the implant surface properties have been reported to be some of the most important critical factors. The effect of implant's surfaces created by resorbable blast media (RBM) followed by laser ablation on bone tissue reactions was examined using the removal torque test and histomorphometric analysis. Methods: Two types of dental implants, RBM-laser implants (experimental group) and RBM implants (control group) (CSM implant system, Daegu, Korea; L=6 mm, diameter=3.75 mm) were placed into the right and left distal femoral metaphysis of 17 adult rabbits. Six weeks after placement, removal torque was measured and histomorphometric analysis was performed. Results: The mean removal torque was $24.0{\pm}10.2Ncm$ and $46.6{\pm}16.4Ncm$ for the control and test specimens, respectively. The experimental RBM-laser implants had significantly higher removal torque values than the control RBM implants (p=0.013). The mean values of total and cortical bone to implant contact (BIC) were respectively $46.3{\pm}10.8%$ and $65.3{\pm}12.5%$ for the experimental group, and $41.9{\pm}18.5%$ and $57.6{\pm}10.6%$ for the control group. The experimental RBM-laser implants showed a higher degree of total and cortical BIC compared with RBM implants, but there was no statistical significance (p=0.482, 0.225). Conclusion: The removal torque and BIC of the test group were higher than those of the control group. In this study, the surface treatment created by RBM treatment followed by laser ablation appears to have a potential in improving bone tissue reactions of dental implants.

• The Journal of Advanced Prosthodontics
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• 제1권2호
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• pp.75-84
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• 2009

STATEMENT OF PROBLEM. A number of studies about the nano-treated surfaces of implants have been conducting along with micro-treated surfaces of implants. PURPOSE. The purpose of this study was to get information for the clinical use of nano-treated surfaces compared with micro-treated surfaces by measuring removal torque and analyzing histological characteristics after the placement of various surface-treated implants on femurs of dogs. MATERIAL AND METHODS. Machined surface implants were used as a control group. 4 nano-treated surface implants and 3 micro-treated surface implants [resorbable blast media surface (RBM), sandblast and acid-etched surface (SAE), anodized RBM surface] were used as experimental groups. Removal torque values of implants were measured respectively and the histological analyses were conducted on both 4weeks and 8weeks after implant surgery. The surfaces of removed implants after measuring removal torque values were observed by scanning electron microscopy (SEM) at 8 weeks. RESULTS. 1. Removal torque values of the nano-treated groups were lower than those of micro-treated groups. 2. Removal torque values were similar in the anodized RBM surface groups. 3. On the histological views, there was much of bone formation at 8 weeks, but there was no difference between 4 and 8 weeks, and between the types of implant surfaces as well. CONCLUSION. it is suggested that implant topography is more effective in removal torque test than surface chemistry. To get better clinical result, further studies should be fulfilled on the combined effect of surface topography and chemistry for the implant surface treatments.

• The Journal of Advanced Prosthodontics
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• 제6권2호
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• pp.126-132
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• 2014

PURPOSE. This study was conducted to evaluate the influence of the implant-abutment connection design and diameter on the screw joint stability. MATERIALS AND METHODS. Regular and wide-diameter implant systems with three different joint connection designs: an external butt joint, a one-stage internal cone, and a two-stage internal cone were divided into seven groups (n=5, in each group). The initial removal torque values of the abutment screw were measured with a digital torque gauge. The postload removal torque values were measured after 100,000 cycles of a 150 N and a 10 Hz cyclic load had been applied. Subsequently, the rates of the initial and postload removal torque losses were calculated to evaluate the effect of the joint connection design and diameter on the screw joint stability. Each group was compared using Kruskal-Wallis test and Mann-Whitney U test as post-hoc test (${\alpha}$=0.05). RESULTS. The postload removal torque value was high in the following order with regard to magnitude: two-stage internal cone, one-stage internal cone, and external butt joint systems. In the regular-diameter group, the external butt joint and one-stage internal cone systems showed lower postload removal torque loss rates than the two-stage internal cone system. In the wide-diameter group, the external butt joint system showed a lower loss rate than the one-stage internal cone and two-stage internal cone systems. In the two-stage internal cone system, the wide-diameter group showed a significantly lower loss rate than the regular-diameter group (P<.05). CONCLUSION. The results of this study showed that the external butt joint was more advantageous than the internal cone in terms of the postload removal torque loss. For the difference in the implant diameter, a wide diameter was more advantageous in terms of the torque loss rate.

• 대한치과보철학회지
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• 제50권4호
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• pp.243-248
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• 2012

연구 목적: 본 연구의 목적은 임플란트 지대주 연결에 사용되는 기성품 나사와 맞춤형 나사의 풀림 토크를 비교하는 것이다. 연구 재료 및 방법: 세가지 임플란트 시스템에(Osstem, Astra, Zimmer) 대해 고정체와 지대주의 연결에 기성품 나사군(대조군)과 맞춤형 나사군(실험군)으로 총 6군(n = 6)으로 나누었다. 조임 토크조절은 디지털 토크 측정기를 이용하였으며 각 임플란트 제조사가 추천한 조임 토크 값을 적용하였다. 체결 10분 후 동일한 조임 토크를 다시 적용하고 5분 후에 풀림 토크력을 측정하였다. 이 과정을 10회 반복 측정하였다. 반복 하중 실험에서는 6개 군(n = 3)에 대해 체결 10분 후 2차 조임 토크를 적용하고 $30^{\circ}$ 경사로 50 N 하중으로 총 1,000,000번 반복 하중을 가하였다. 반복 하중 적용 이후 풀림 토크값을 측정하였다. 통계 방법으로는 10회 반복 측정에서 풀림 토크값의 차이를 비교하기 위해 repeated measures of ANOVA test (${\alpha}$=.05)를 사용하였고, 반복 하중 후 풀림 토크값의 차이를 비교하기 위해서 각 시스템별 Independant t-test로 통계 처리하였다. 결과: 모든 군에서 반복 횟수가 증가할수록 풀림 토크값이 유의성 있게 감소하는 것으로 나타났다(P<.05). 10회 반복 측정 실험에서는 세 종류의 임플란트에서 대조군(기성품나사)과 실험군(맞춤형 나사) 간에 풀림 토크값은 유의차가 없었다(P>.05). 반복 하중 실험에서 세가지 시스템에서 대조군과 실험군 간의 풀림 토크력은 유의한 차이가 없었다(P>.05). 결론: 반복 측정된 풀림력 검사와 반복 하중을 적용 후 풀림력 검사에서 맞춤형 나사와 기성품 나사의 풀림력은 유의한 차이가 없었다.

• 대한치과보철학회지
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• 제50권3호
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• pp.149-155
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• 2012

연구 목적: 이 논문은 임플란트 고정체가 골융합이 이루어지기전 의원성 동요가 있을 경우 골결합에 어떤 영향을 미치는지를 알아 보고자 한다. 연구 재료 및 방법: 실험에 사용한 임플란트는 직경 3.73 mm, 길이 4 mm의 순수한 타이타늄과 RBM ($MegaGen^{(R)}$: Ca-P) 처리된 임플란트(Grade IV)를 사용하였다. 몸무게 3.5kg 이상의 토끼(Female, New Zealand White)의 한쪽 경골에 2개씩 양쪽 다리에 임플란트를 식립하여 모두 80개의 임플란트가 식립되었다. 비틀림 제거력(Removal torque)의간격에 따라 그룹 I (6주), 그룹 II (4일+6주), 그룹 III (4일+1주+6주), 그룹 IV (1주+6주), 그룹 V (1주+1주+6주), 그룹 VI (2주+6주), 그룹 VII (2주+1주+6주), 그룹 VIII (3주+6주), 그룹 IX (3주+1주+6주), 그룹 X (10주)으로 10개의 그룹으로 나누었다. 본 실험에서 그룹 I과 그룹X가 대조군이며, 비틀림 제거력은 digital torque gauze (Mark-10, USA)를 사용하여 6주와 10주에 측정하였다. 실험군에서는 마지막 비틀림 제거력을 측정하기 전에 의원성 동요를 가하여 한 번 혹은 두 번 비틀림 제거력을 측정하여 그 수치를 기록하였다. 그 후, 대조군을 제외하고 비틀림 제거력을 측정한 임플란트는 가급적 원래의 위치로 돌려 놓고 봉합을 하였다. 모든 실험군은 마지막 비틀림 제거력 측정전까지 6주간의 치유기간을 주었으며, 마지막 비틀림 제거력은 실험군 첫 번째 또는 두 번째 비틀림 제거력값과 비교하여 결과를 분석하였다. 결과: 마지막 비틀림 제거력 측정값에서 그룹X (10주)의 값이 대조군인 그룹 I (6주)의 값보다 높았으나, 통계적으로는 유의하지 않았다. 실험군과 대조군 사이의 통계적으로 유의한 차이를 보이지 않았다(P>.05). 첫 번째 비틀림 제거력 측정치에서, 실험군(4일혹은1주)에서 다른 실험군(2주혹은3주)의 수치보다 낮은 값을 보였다. 치유기간에 따른 각 실험군의 비교에서, 최종 비틀림 제거력 값이 첫 번째 비틀림 제거력 값 보다 현저히 높은 값을 보였다. 결론: 골유착이 형성되기 전 한 번 또는 두 번 의원성으로 동요는, 만약 충분한 치유기간을 가지게 될 경우 임플란트의 골유착에 영향을 주지 않는다.

• The Journal of Advanced Prosthodontics
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• 제11권6호
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• pp.305-312
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• 2019

PURPOSE. The purpose of this study was to compare computer-aided design/computer-aided manufacturing (CAD/CAM) abutment and prefabricated abutment in Morse taper internal connection type implants after cyclic loading. MATERIALS AND METHODS. The study was conducted with internal type implants of two different manufacturers (Group Os, De). Fourteen assemblies were prepared for each manufacturer group and divided into 2 groups (n=7): prefabricated abutments (Os-P, De-P) and CAD/CAM abutments (Os-C, De-C). The amount of axial displacement and the removal torque values (RTVs) were measured before and after cyclic loading (10⁶ cycles, 3 Hz with 150 N), and the tensile removal force to dislodge the abutments was measured after cyclic loading. A repeated measures ANOVA and a pattern analysis based on the logarithmic regression model were conducted to evaluate the effect of cyclic loading on the axial displacement. The Wilcoxon signed-rank test and the Mann-Whitney test was conducted for comparison of RTV reduction% and tensile removal forces. RESULTS. There was no significant difference between CAD/CAM abutments and prefabricated abutments in axial displacement and tensile removal force; however, significantly greater RTV reduction% after cyclic loading was observed in CAD/CAM abutments. The correlation among the axial displacement, the RTV, and the tensile removal force was not significant. CONCLUSION. The use of CAD/CAM abutment did not significantly affect the amount of axial displacement and tensile removal force, but presented a significantly greater removal torque reduction% than prefabricated abutments. The connection stability due to the friction at the abutment-implant interface of CAD/CAM abutments may not be different from prefabricated abutment.

• 구강회복응용과학지
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• 제31권3호
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• pp.203-211
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• 2015

목적: 완전한 골-임플란트 결합을 가졌던 임플란트가 갑자기 골유착을 잃은 경우의 시간에따른 재골유착을 연구하기 위함이다. 연구 재료 및 방법: 23마리 토끼의 좌우 경골에 각각 2개씩 실험목적으로 제작한 RBM임플란트를 식립 후, 6주 후에 1차로 비틀림 제거력을 측정한 다음, 임플란트를 다시 재위치 침하시키고, 4일, 7일, 11일, 2주, 4주, 6주, 그리고 8주의 재침하시간 경과 후 2차로 비틀림 제거력을 측정하고 시편을 제작하여 조직 형태학적 검사를 하였다. 통계학적 검사를 위해 paired t-test를 시행했고, One-way ANOVA와 Tukey's post-hoc test 통해 그룹간 차이를 비교하여 다음과 같은 결과를 얻었다. 결과: 1차 비틀림 제거력과 비교해봤을 때 2차에서 11일 후에는 증가했으며, 2주 후부터 유의성 있게 증가하였다. 형광조사검사에서, 7일 후부터 골-임플란트 계면 사이에 형광밴드가 나타나는 광물화 현상이 관찰되고, 11일 후부터는 분명한 골 형성이 나타났다. 결론: 토끼에서는 11일 이후가 되면 충분한 재골유착을 얻을 수 있었다.

• Journal of Korean Dental Science
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• 제4권1호
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• pp.26-32
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• 2011

Purpose: The quality of implant surface is one of the factors that influence wound healing of implant site and subsequently affect osseointegration. The objective of modification of the surface properties of an implant is to affect the biological consequence. The purpose of this study is to evaluate the biologic response of osseous tissue to anodized implants. Materials and Methods: Two machined titanium implants for control group were installed in a tibia of each rabbit and two anodized implants for test group were installed in the other tibia of each rabbit. At the moment the implants were installed, resonance frequency analysis (RFA) values were measured. After healing periods of 1, 2, 3, and 7 weeks, the implants were uncovered and RFA values were measured again. Removal torque was measured for one implant in the test group and one implant in the control group. Histological evaluation was executed in the other implants. Results: Both of test group and control group have the tendency of greater RFA change rate and removal torque value as healing periods became longer, but were statistically insignificant (P>0.05). However, in the case of the same healing period, the test group tended to have greater RFA change rate and removal torque than the control group (P<0.05). More active new bone formation from endosteal surface was noted on the anodized surface than machined surface in specimen after 1 week. There were no significant differences between the test group and control group in histological evaluations. Conclusion: In summary, the anodized surface showed slightly favorable results and it is postulated that it may facilitate improved stability in bone.

• Journal of Periodontal and Implant Science
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• 제29권1호
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• pp.209-231
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• 1999

Even though titanium(Ti) and its alloys are the most used dental implant materials, there are some problems that Ti wears easily and interferes normal osteogenesis due to the metal ions. Ti coated with bioactive ceramics such as hydroxyapatite has also such problems as the exfoliation or resorption of the coated layer, Recent studies on implant materials have been proceeding to improve physical properties of the implant substrate and biocompatibility of the implant surfaces. The purpose of the present study was to examine the physical property and bone tissue compatibility of bioinert nitrides ion plated Ti, Button type specimens(14mm in diameter, 2.32rrun in height) for the abrasion test and cytotoxicity test and thread type implants(3.75mm in diameter, 6mm in length) for the animal experiments were made from Ti(grade 2) and 316LVM stainless steel. Ti specimens were ion plated with TiN, ZrN by the low temperature arc vapor deposition, and the depth profile of the TiN/Ti, ZrN/Ti ion plated surface was examined by Auger Electron Spectroscopy. Three kind of button type specimens .of TiN/Ti, ZrN/Ti and Ti were used for abrasion test, and HEPAlClC7 cells and CCD cells were cultivated for 4 days with the specimens for cytotoxicity test. Thread type implants of TiN/Ti, ZrN/Ti, Ti, 316LVM were implanted on the femur of 6 adult dogs weighing 10kg-13kg. Two dogs were sacrified for histological examination after 45 days and 90 days, and four dogs were sacrified for the removal torque test of the implant') after 90 days. The removal torque force was measured by Autograph (Shimadzu Co., AGS-1000D series, Japan). Abrasion resistance of TiN/Ti was the highest, and that of ZrN/Ti and Ti were followed. The bioinert nitride ion plated Ti had much better abrasion resistance, compared with Ti, In the cytotoxicity test, the number of both cells were increased in all specimens, and there were no significant difference in cytotoxic reaction among all groups (p>0.1), In histological examination, 316LVM showed the soft tissue engagement in interface between the implant and bone, but the other materials after 45 days noted immature new bone formation in the medullary portion along the implant surface, and those after 90 days showed implant support by new bone formation in both the cortical and the medullary portion, The removal torque force of Tilv/Ti showed significantly higher than that of Ti(p(O,05). The difference in removal torque force between TiN/Ti and ZrN/Ti was not significant(p>0.05), and that of 316LVM was lowest among all groups(p<0.05). These results suggest that bioinert nitrides ion plated Ti can resolve the existing problems of Ti and bioactive ceramics, and it may be clinically applicable to human.