• 대한치과보철학회지
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• 제44권3호
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• pp.314-324
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• 2006

Statement of problem. Osseointegration is important mechanism of dental implant but it is not easy to evaluate. Indirect measurement is non-invasive and clinically applicable but they need more study about correlation between indirect values and degree of osseointegration. Purpose. The aims of this study were to evaluate the coefficient of correlation between indirect measurement and direct measurement under different healing time, and assessment of effect of initial insertion torque to the implant stability. Material and Methods. 20 rabbits received 3 implants on each side of tibia. Three kinds of implants (machined surface implant, Sandblasted with Large grit and Acid etched implant, Resorbable Blast Media treated implant) were used. During the surgery implant insertion torque were measured with $Osseocare^{TM}$. After the 1, 4, 8, 12 weeks of healing time, animals were sacrificed and stability values (Implant Stability Quotient with $Osstell^{TM}$, removal torque with torque gauge) were measured. Results. The Bone quality of rabbit tibia was classified into 2 groups according to the insertion torque. Resonance frequency analysis (ISQ) and removal torque showed positive correlation until $4^{th}$ week (r=0.555, p=0.040). After $8^{th}$ week (r=0.011, p=0.970) the correlation became weak and it turned negative at $12^{th}$ week (r=-0.074, p=0.801). Insertion torque and ISQ showed changing correlation upon the healing time ($1^{st}$ week: r=0.301, p=0.033, $4^{th}$ week: r=-0.429, p=0.018, $8^{th}$ week: r=0.032, p=0.865, $12^{th}$ week: r=-0.398, p=0.029). Insertion torque and removal torque has positive correlation but it was not statistically significant ($1^{st}$ week: r=0.410, p=0.129, $4^{th}$ week: r=0.156, p=0.578, $8^{th}$ week: r=0.236, p=0.398, $12^{th}$ week: r=0.260, p=0.350). Conclusion. In this study, bone quality may affect the degree of osseointegration positively during healing time and correlation between ISQ and degree of osseointegration can be different according to the healing time and bone quality.

• 대한치과보철학회지
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• 제52권4호
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• pp.298-304
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• 2014

목적: 본 선행 연구는 recombinant human transforming growth factor-${\beta}2$ (rhTGF-${\beta}2$)/ poly lactic-co-glycolic acid (PLGA) 복합체를 타이타늄 임플란트에 처리하였을 때 골 유착에 미치는 영향을 알아보기 위해 시행된 것으로 토끼 모델을 사용하였다. 재료 및 방법: 8개의 임플란트를 300V에서 3분 동안 양극 산화하였다. 그 중 4개는 electrospray법으로 rhTGF-${\beta}2$/PLGA를 코팅하여 실험군으로 설정하였다. 4마리의 New Zealand rabbit의 tibiae에 1개씩의 실험군과 대조군 임플란트를 식립하였으며, 3주와 6주에 2마리씩 희생하여 micro-computed tomography(microCT) 촬영 후 분석하였다. 결과: Scanning electron microscope (SEM) 사진에서 rhTGF-${\beta}2$/PLGA 입자가 임플란트 표면에 균일하게 분산되어 있음을 확인하였다. MicroCT 분석 결과 통계적으로 유의하지는 않지만 rhTGF-${\beta}2$/PLGA를 처리한 임플란트가 bone volume/total volume (BV/TV)와 trabecular thickness (Tb.Th) 값이 더 높은 경향성을 보였으며, cross sectional view에서 더 많은 골이 형성되었음을 확인하였다. 결론: rhTGF-${\beta}2$/PLGA 표면처리된 임플란트가 주변 골의 양적 성장을 촉진시킬 수 있으며 임플란트 초기 골 유착을 증진시킬 수 있는 가능성을 보였다.

• Journal of Periodontal and Implant Science
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• 제48권4호
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• pp.202-212
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• 2018

Purpose: Bone-to-implant contact (BIC) is difficult to measure on micro-computed tomography (CT) because of artifacts that hinder accurate differentiation of the bone and implant. This study presents an advanced algorithm for measuring BIC in micro-CT acquisitions using a spiral scanning technique, with improved differentiation of bone and implant materials. Methods: Five sandblasted, large-grit, acid-etched implants were used. Three implants were subjected to surface analysis, and 2 were inserted into a New Zealand white rabbit, with each tibia receiving 1 implant. The rabbit was sacrificed after 28 days. The en bloc specimens were subjected to spiral (SkyScan 1275, Bruker) and round (SkyScan 1172, SkyScan 1275) micro-CT scanning to evaluate differences in the images resulting from the different scanning techniques. The partial volume effect (PVE) was optimized as much as possible. BIC was measured with both round and spiral scanning on the SkyScan 1275, and the results were compared. Results: Compared with the round micro-CT scanning, the spiral scanning showed much clearer images. In addition, the PVE was optimized, which allowed accurate BIC measurements to be made. Round scanning on the SkyScan 1275 resulted in higher BIC measurements than spiral scanning on the same machine; however, the higher measurements on round scanning were confirmed to be false, and were found to be the result of artifacts in the void, rather than bone. Conclusions: The results of this study indicate that spiral scanning can reduce metal artifacts, thereby allowing clear differentiation of bone and implant. Moreover, the PVE, which is a factor that inevitably hinders accurate BIC measurements, was optimized through an advanced algorithm.

• 한국임상수의학회지
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• 제37권5호
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• pp.261-269
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• 2020

The purpose of this study is to investigate the clinical effects of carboxymethyl chitosan (CMC) and adipose-derived mesenchymal stem cells (MSCs) on osteoarthritis (OA). Thirty New Zealand white rabbits were used as cranial cruciate ligament transection and partial meniscectomy models. The rabbits were divided into five groups (n = 6) according to the intra-articular injection materials: the control group with PBS, the HA group with hyaluronic acid, the CMC group with CMC, the MSC group with MSCs emerged in PBS, and the MSC+CMC group with CMC and MSCs. Knee thickness, extension angle, gross morphology, histopathology and immunohistochemistry were performed to evaluate the effects of CMC and MSCs on rabbit OA. On the morphologic and histologic examination, the articular surfaces of the femur and tibia were markedly damaged in control group with higher Mankin score and lower cartilage surface thickness. However, OA related cartilage defects were alleviated by the treatment of MSC and/or CMC. The expressions of apoptotic and inflammatory cytokines were decreased and cartilage extracellular matrix (ECM) related collagens I and II were enhanced by the treatment of MSC and/or CMC. In conclusion, this study showed that CMC and MSC treatments have a beneficial effects on OA via the protection of cartilage damage, the stimulation of ECM, and the inhibition of inflammatory and apoptotic reaction.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제28권5호
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• pp.434-444
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• 2006

This study was performed to evaluate the effects of three different implant surface treatments to the bone formation during osseous healing period under unloading conditions. Machined, double-acid etched and anodic oxidized implants were inserted into tibia of 3.0 - 3.5 kg NZ white male rabbits and 2 animals of each group were sacrificed at 2, 4 and 8 weeks. The specimens containing implant was dehydrated and embedded into hard methylmethacrylate plastic. After grinding to $50{\mu}m$, the specimens were stained with Villanueva bone stain. From each specimen, histomorphometric evaluation and the bone implant contact rate were analysed with optical microscope. The results were as follows; 1. In the scanning electronic microscopic examination, machined surface implant had several shallow and paralleled scratches on plain surface, double acid-etched implant had lots of minute wrinkles, rough valley and also irregularly located craters that looked like waves, anodic oxidized surface implant had porosity that minute holes were wholly distributed on the surface. 2. After 2 weeks of implantation, the percentages of bone-to-implant contact in the machined implant, double acid-etched implant and anodic oxidized implant were 26.85%, 62.64% and 59.82%, after 4 weeks of implantation they were 64.29%, 77.85% and 75.23%, and after 8 weeks they were 82.66%, 85.34% and 86.39%. 3. After 2 weeks of implantation, the percentages of bone area between threads in the machined implant, double acid-etched implant and anodic oxidized implant were 21.55%, 42.81%, and 40.33%, after 4 weeks of implantation they were 49.32%, 62.60% and 75.56%, and after 8 weeks they were 71.62%, 87.73% and 83.94%. In summary, percentages of implant surface contacted to bone trabeculae and bone formation area inside threads in double acid-etched implants and anodic oxidized implants were greater than machined implants in early healing stage. These results suggest that double acid-etched and anodic oxidized surface implants could reduce the healing period for osseointegration and may enable to do early function.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제42권4호
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• pp.187-192
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• 2016

Objectives: In this study, we investigated whether a high-fat diet (HFD) affected the bone implant connection (BIC) in peri-implant bone. Materials and Methods: Four male rabbits were used in this study. Dental implant surgery was introduced into each tibia, and four implants were integrated into each animal. In both the normal diet (ND) group (n=2) and HFD group (n=2), 8 implants were integrated, for a total of 16 integrated implants. The animals continued with their respective diets for 12 weeks post-surgery. Afterward, the rabbits were sacrificed, and the BIC was assessed histomorphometrically. Results: Histologic and histomorphometric analyses demonstrated that BIC was not impaired in the HFD group compared to the ND group. Conclusion: Within the limitations of this study, we found that HFD did not decrease the BIC in rabbit tibias.

• 대한치과보철학회지
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• 제42권3호
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• pp.294-300
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• 2004

The present experimental study was designed to address two issues. The first was to investigate whether oxidation voltage of titanium implants influenced bone tissue responses after an in vivo implantation. The second aim was to investigate secondary stability change after 1 to 3months period. Screw-shaped implants with a wide range of oxide properties were prepared by electrochemical oxidation methods, where the oxide thickness varied in the range of $3-15{\mu}m$. The micro structure revealed pore sizes of $1-3{\mu}m$, the crystal structures of the titanium oxide were amorphous, anatase and a mixture of anatase and rutile type. Bone tissue responses were evaluated by resonance frequency measurements that were undertaken 1 to 3months after insertion in the rabbit tibia. It was concluded that no statistical difference of RFA values was found between the groups, RFA gains after Imonth and 3months were calculated.

• Journal of Periodontal and Implant Science
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• 제33권4호
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• pp.625-641
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• 2003

Background: This study presents a biomechanical and histometric comparison of bone response to implants with various area of hydroxyapatite(HA) coating. Methods: The implants were placed in the tibia of 10 rabbits weighing 2.5-3.5kg. The control group had a machined surface, the experimental group 1 had 50${\mu}m$ thick HA coated in a band form, and the experimental group 2 had 50${\mu}m$ thick HA coated on the entire surface. 8 weeks after implantation, the animals were sacrificed. Removal torque was measured and histologic preparation was also performed for histologic and histometric analysis. Bone to implant contact as well as percentage of bone area inside threads were measured. ANOVA post hoc, and t-test were used for statistical analysis with p-value p<0.05. Results: 1. The removal torques were 9.36${\pm}$5.64 Ncm, 48.40 ${\pm}$ 16.66 Ncm, and 82.37${\pm}$22.56 Ncm for the control, exp. 1, and exp. 2 group respectively. Statistically significant difference were found among all the groups(p<0.05). 2. Bone to implant contact in the cortical bone were 38.94${\pm}$10.9 %, 66.90${\pm}$14.1 %, 73.00${\pm}$19.4 %, in the marrow bone, 8.30${\pm}$5.4%, 14.59${\pm}$5.9%, 18.54${\pm}$11.8%, and in total, 22.40${\pm}$10.1%, 31,17${\pm}$7.5%, 41.41${\pm}$12.2% for the control, exp. 1, and exp. 2 group respectively . In the cortical bone, exp. 1, and exp. 2 group showed statistically significantly higher contact compared to control group. Total contact and in the marrow bone, only exp. 2 group showed statistically significantly higher contact compared to control group(p<0.05). In all the groups significantly higher contact were observed in the cortical bone compared to the marrow bone(p<0.05). 3. Percentage of bone area inside threads in the cortical bone were 55.68${\pm}$7.25%, 55.19${\pm}$13.19%, 57.04${\pm}$13.33%, in the marrow bone, 12.34${\pm}$14.61%, 17.56${\pm}$20.04%, 20.26${\pm}$12.83%, and in total, 30.30${\pm}$12.46%, 31.57 ${\pm}$15.15%, 34.25${\pm}$12.56% for the control, exp.1, and exp. 2 group respectively. There was no statistical difference among the groups. In all the groups significantly higher bone area were observed in the cortical bone compared to the marrow bone(p<0.05)

• 구강회복응용과학지
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• 제24권1호
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• pp.41-56
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• 2008

상용 임플란트의 표면을 개질하기 위해 물리적, 화학적 방법을 이용한 새로운 표면이 증가하고 있으며 이에 대한 골반응도 다를 것으로 예상할 수 있지만 대부분의 연구는 단순히 기계절삭형 임플란트와의 비교만을 하고 있다. 본 연구에서는 4종의 다른 개질된 표면을 가진 상용 임플란트를 가토의 경골에 식립한 후 생역학적, 조직형태학적으로 비교하였다. 연구 결과, 모든 임플란트는 6주 후 안정적인 골유착을 이루고 있었으며 4종의 표면개질의 차이에 의한 공진주파수 및 조직형태학적 골반응의 차이는 없었으며 표면개질을 비교하기 위해 피질골 하방으로 증식한 골을 비교하는 것이 유용하였다. 생역학적, 조직형태학적 골반응에 비해 미세단층촬영(micro-CT)를 이용하는 비교법은 유용성과 정확도가 낮은 것으로 나타났다.

• The Journal of Advanced Prosthodontics
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• 제1권2호
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• pp.107-112
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• 2009

STATEMENT OF PROBLEM. Macroscopic and especially microscopic properties of implant surfaces play a major role in the osseous healing of dental implants. Dental implants with modified surfaces have shown stronger osseointegration than implants which are only turned (machined). Advanced surface modification techniques such as anodic oxidation and Ca-P application have been developed to achieve faster and stronger bonding between the host bone and the implant. PURPOSE. The purpose of this study was to investigate the effect of surface treatment of titanium dental implant on implant stability after insertion using the rabbit tibia model. MATERIAL AND METHODS. Three test groups were prepared: sandblasted, large-grit and acid-etched (SLA) implants, anodic oxidized implants, and anodized implants with Ca-P immersion. The turned implants served as control. Twenty rabbits received 80 implants in the tibia. Resonance frequencies were measured at the time of implant insertion, 2 weeks and 4 weeks of healing. Removal torque values (RTV) were measured 2 and 4 weeks after insertion. RESULTS. The implant stability quotient (ISQ) values of implants for resonance frequency analysis (RFA) increased significantly (P <. 05) during 2 weeks of healing period although there were no significant differences among the test and control groups (P >. 05). The test and control implants also showed significantly higher ISQ values during 4 weeks of healing period (P < .05). No significant differences, however, were found among all the groups. All the groups showed no significant differences in ISQ values between 2 and 4 weeks after implant insertion (P >. 05). The SLA, anodized and Ca-P immersed implants showed higher RTVs at 2 and 4 weeks of healing than the machined one (P < .05). However, there was no significant difference among the experimental groups. CONCLUSION. The surface-modified implants appear to provide superior implant stability to the turned one. Under the limitation of this study, however, we suggest that neither anodic oxidation nor Ca-P immersion techniques have any advantage over the conventional SLA technique with respect to implant stability.