• Korean Journal of Materials Research
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• v.8 no.7
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• pp.613-615
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• 1998

임프란트의 외표면적이 골과의 결합의 정도에 미치는 영향을 알아보기 위하여 10개의 grade ll 티타늄 임프란트를 사용하여 이를 직경 3미리와 5미리의 2개의 군으로 나누어 10마리의 토끼의 무릅뼈에 삽입하였다. 6주후에 동물들을 희생시키고 회전제거력을 Tohnichi 15-BTG-N Torque garge Manometer로 측정하여 5nmwlrrud 그룹의 회전제거력이 3mm직경 그룹의 회전제거력보다 큰 것을 확인하였다. (p=0.008)

• The korean journal of orthodontics
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• v.38 no.5
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• pp.328-336
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• 2008

Objective: The purpose of this study was to compare the torque resistance to removal of sandblasted large grit and acid etched (SLA) surface treated orthodontic mini-implants and smooth surface orthodontic mini-implants as well as performing histologic observations. Methods: Two groups of custom screw shaped orthodontic mini-implants (C-implant, 1.8 mm outer diameter $\times$ 9.5 mm length, Cimplant, Seoul, Korea) were designated. 22 SLA treated C-implants (SLA group) and 22 machined surface C-implants (machined group) were placed in the tibia metaphysis of 11 adult New Zealand white rabbits. Following a 6-week healing period, the rabbits were sacrificed. Subsequently, the C-implants were removed under reverse torque rotation with a digital torque measuring device and independent t-test was performed. Selected tissues were prepared for histologic observation. Results: The SLA group presented a higher mean removal torque value (6.286 Ncm) than the machined group (4.491 Ncm) which was statistically significant (p < 0.005). Histologic observation revealed a trend of more new bone formation in contact with the screw surface in the SLA group than the smooth group. Conclusions: The results of this study suggested that SLA surface treatment can enhance the osseintegration potential for C-orthodontic mini-implants.

• The korean journal of orthodontics
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• v.37 no.6
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• pp.400-406
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• 2007

The purpose of this experimental study was to evaluate the effect of immediate orthodontic loading on the stability at the bone-implant interface of titanium miniscrews in a rabbit model. Methods: Forty titanium miniscrews (1.6 mm diameter, 8 mm length) were inserted in the tibiae of 10 rabbits. Twenty test group miniscrews were subjected to continuous orthodontic forces of 200g immediately after implantation for a period of 6 weeks. The remaining 20 control group miniscrews were left unloaded for the same follow-up interval. Removal torque values were recorded using a digital torque gauge. An independent t-test was performed. Results: All the miniscrews were stable, and exhibited no mobility or displacement throughout the experimental period. Histologically, miniscrews were well-integrated into bone. No statistically significant differences in removal torque data were found between the loaded test and the unloaded control groups. Conclusions: These findings suggest that titanium miniscrews can be used as anchoring units for orthodontic tooth movement immediately after insertion.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.4
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• pp.328-334
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• 2019

Purpose: The aim of this study was to confirm if Laser-treated implants were soaked in 0.9% NaCl solution for 2 weeks could increase the surface hydrophilicity, and the Remoal Torque of each implant that inserted in rabbit tibia for initial healing period of 10 days. Materials and methods: Twenty machined titanium surface screws were produced with a diameter 3 mm, length 8 mm. Ten screws had their surface treated with a laser only (laser treated group), and the other 10 were soaked in saline for 2 weeks after surface treatment with a laser (laser treated + saline soaked group). Implants were inserted in rabbit tibia (ten adult New Zealand white rabbits), and the RTQ of each implant was measured after 10 days. The wettability among implants was compared by measuring the contact angle. Surface composition and surface topography were analyzed. Results: After 10 days, the laser treat + soaking group implants had a significantly higher mean RTQ than the laser treated implants (P = .002, < .05). There were no significant morphological differences between groups, and no remarkable differences were found between the two groups in the SEM analysis. Conclusion: Saline soaking implants is expected to produce excellent RTQ and surface analysis results.

• The korean journal of orthodontics
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• v.36 no.5
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• pp.324-330
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• 2006

Objective: The purposes of this study were to evaluate the differences between sand blasted, large grit and acid-etched (SLA) treated mini-implants and smooth surface orthodontic mini-implants in relation to the removal torque as well as the histologic analysis. Methods: Custom-made, screw-shaped, titanium implants with a length of 9.5 mm and an outer diameter of 1.8 mm were divided into 2 groups; the SLA group (20 SLA treated orthodontic mini-implants) and the smooth surface group (20 smooth surface mini-implants), and placed In the tibia metaphysis of 10 rabbits. Each rabbit had 4 mini-implants placed, 2 in each tibia. The right tibia were implanted with the SLA group mini-implants and the left tibia had the smooth group mini-implants placed. Each mini-implant group were immediately applied with a continuous traction force of 150 g using a Ni-Ti coil spring. The rabbits were sacrificed 6 weeks post-surgically. Subsequently, the legs were stabilized, the Ni-Ti coil springs were removed and the mini-implants were removed under reverse torque rotation with a digital torque gauge. Results: 6 weeks after placement, the SIA group presented a higher mean removal torque value (8.29 Ncm) than the smooth group (3.34 Ncm) and histologic analysis revealed a higher new bone formation aspect along the screw in the SLA group. Conclusion: Results of this study indicates that SLA treated mini-implants may endure higher orthodontic forces without loosening.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.4
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• pp.335-341
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• 2019

Purpose: Chemically strong-acids (HF and $HCl/H_2SO_4$) dual etching implant surfaces have higher strengths of osseointegration than machined implant surfaces. However, the dual acid treatment deteriorates the physical properties of the titanium by weakening the fatigue resistance of the implant and causing microcracks. The removal torque comparison between the dual-acid etched (hydrochloric acid, sulfuric acid, HS) and single-acid etched implants (hydrochloric acid, H) could reveal the efficiency of implant surface acid treatment. Materials and methods: Nine $3.75{\times}4mm$ dual-acid etched SLA implants and nine single-acid etched SLA implants were inserted into New Zealand rabbit tibias. After 10 days, removal torque, roughness, and wetting angle were measured. Results: Mean removal torque values were as follows: Mean removal torque were 9.94 Ncm for HS group and 9.96 Ncm for H group (P=.995). Mean surface roughness value were $0.93{\mu}m$ for HS group and $0.84{\mu}m$ for H group (P=.170). Root mean square roughness (RSq) values were $1.21{\mu}m$ for HS group and $1.08{\mu}m$ for H group (P=.294), and mean wetting angle values were $99^{\circ}$ for HS group and $98^{\circ}$ for H group (P=.829). Statistical analysis showed no significant difference between the removal torques, roughness, or wetting angles of the two groups. Conclusion: In this experiment, we found no significant difference in removal torque, roughness, or wetting angle between dual-acid etched and single-acid etched implants.

• The Journal of Korean Academy of Prosthodontics
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• v.56 no.1
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• pp.1-7
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• 2018

Purpose: The purpose of this study is to investigate the effect of the titanium implant soaked in saline after RBM surface treatment on the initial osseointegration by comparing the removal torque and the surface analysis compared to the titanium implant with only RBM surface treatment. Materials and methods: The control group was RBM surface treated implants (RBM), and the test group was implants soaked in saline for 2 weeks after RBM surface treatment (RBM+Sal). The control and test group implants were placed in the left and right tibiae of 10 rabbits, respectively, and at the same time, the insertion torque (ITQ) was measured. After 10 days, the removal torque (RTQ) was measured by exposing the implant site. FE-SEM, EDS, Surface roughness and Raman spectroscopy were performed for the surface analysis of the new implant specimens used in the experiments. Results: There was no significant difference in insertion torque and removal torque between RBM surface treated titanium implants and saline-soaked titanium implants after RBM surface treatment. Conclusion: Saline soaking after RBM surface treatment of titanium implants did not positively affect the initial osseointegration as compared to titanium implants with only RBM surface treatment.

• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.1
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• pp.1-9
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• 2018

Purpose: The purpose of this study is to investigate the effect of the titanium implant soaked in saline after RBM and acid etched surface treatment on the initial osseointegration by comparing the removal torque and the surface analysis compared to the titanium implant with only RBM and acid etched surface treatment. Materials and Methods: The control group was RBM and acid etched surface treated implants (RBM + HCl), and the test group was implants soaked in saline for 2 weeks after RBM and acid etched surface treatment (RBM + HCl + Sal). The control and test group implants were placed in the left and right tibiae of 10 rabbits, respectively, and at the same time, the insertion torque (ITQ) was measured. After 10 days, the removal torque (RTQ) was measured by exposing the implant site. FE-SEM, EDS, Surface roughness and Raman spectroscopy were performed for the surface analysis of the new implant specimens used in the experiments. Results: There was significant difference in insertion torque and removal torque between control group and experimental group (P = 0.014 < 0.05). Surface roughness of experimental group is higher than control group. Conclusion: Saline soaking after RBM and acid etched surface treatment of titanium implants were positively affect the initial osseointegration as compared to titanium implants with only RBM and acid etched surface treatment.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.10a
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• pp.57-62
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• 2001

밀링은 회전공구를 사용하여 금속을 제거하는 효율적인 방법으로, 특히 수직밀링은 고능률절삭의 이점 때문에 널리 사용되는 금속절삭 가공방법중의 하나이다. 그러나 밀링커터는 단속절삭 공구로서 절삭 날의 단속절삭작용에 의한 변동절삭력과, 여러 날의 동시가공에 의한 절삭력의 교란 때문에 가공능률, 가공정밀도, 기계와 공구의 수명향상에 문제가 되어 왔다. 이러한 문제점들을 해결하기 위하여 기계설계자들은 절삭력의 교란에 의하여 일어나는 진동을 줄이기 위하여 기계구조의 강성을 증가시켰으나 이석은 고비용을 필요로 하게 되므로 공구 형상을 개선하여 안정된 절삭을 시도하였다.

• Journal of the Korea Convergence Society
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• v.10 no.2
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• pp.21-28
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• 2019

The study was to expand the choice of electric toothbrush by number of operations of the plaque removal effect on the tooth surface. Three different toothbrushes were selected for oscillations and pulsations type of electric toothbrush. A is Oral-B D12 (7,600 pulsations), B is Oral-B D16 (20,000 oscillations and a 7,600 pulsations), C is Oral-B D20 (40,000 oscillations and an 8,800 pulsations). In each trial, each tooth was brushed for 2 seconds. For the 10 trials. And each tooth was coated with 1layer, 2layers and 3layers. After the experiment, the plaque removal effect was calculated and analzed using the Image J program(p<0.05). According to the study, C toothbrush had the highest rate of plaque removal effect. Based on this results of the study, dental worker will need to evaluate oral hygiene and recommend appropriate toothbrushes according to oral conditions.