• The korean journal of orthodontics
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• v.30 no.6 s.83
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• pp.677-685
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• 2000

Anchorage plays an important role in orthodontic treatment. Because of limited anchorage Potential and acceptance problems of intra- or extraoral anchorage aids, endosseous implants have been suggested and used. However, clinicians have hesitated to use endosseous implants as orthodontic anchorage because of limited implantation space, high cost, and long waiting period for osseointegration. Titanium miniscrews and microscrews were introduced as orthodontic anchorage due to their many advantages such as ease of insertion and removal, low cost, immediate loading, and their ability to be placed in any area of the alveolar bone. In this study, a skeletal Class II Patient was treated with sliding mechanics using M.I.A.(micro-implant anchorage). The maxillary micro-implants provide anchorage for retraction of the upper anterior teeth. The mandibular micro-implants induced uprighting and intrusion of the lower molars. The upward and forward movement of the chin followed. This resulted in an increase of the SNB angle, and a decrease of the ANB angle. The micro-implants remained firm and stable throughout treatment. This new approach to the treatment of skeletal Class II malocclusion has the following characteristics . Independent of Patient cooperation. . Shorter treatment time due to the simultaneous retraction of the six anterior teeth . Early change of facial Profile motivating greater cooperation from patients These results indicate that the M.I.A. can be used as anchorage for orthodontic treatment. The use of M.I.A. with sliding mechanics in the treatment of skeletal Class II malocclusion increases the treatment simplicity and efficiency.

• The Journal of Korean Academy of Prosthodontics
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• v.42 no.6
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• pp.664-670
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• 2004

Statement of problem. One of the common problems of dental implant prosthesis is the loosening of the screw that connects each component, and this problem is more common in single implant-supported prostheses with external connection. Purpose. The purpose of this study was to examine the changes of detorque values of abutment screws with external connection in different abutment heights. Materials and methods. After cyclic loading on three different abutment heights, detorque values were measured. Abutments were retained with titanium abutment screws tightened to 30 Ncm (30.5 kgmm) with digital torque gauge as recommended by the manufacturer. Replacing abutments, implants and titanium abutment screws with new ones at every measurement, initial detorque values were measured six times. In measuring de torque values after cyclic loading, Avana Cemented Abutments of 4.0 mm collar, 7.0 mm height (Osstem Co., Ltd., Seoul, Korea) were used with three different lengths of 5.0, 8.0, 11.0 mm. Shorter abutments were made by milling of 11.0 mm abutment to have the same force-exercised area of 4.5 mm diameter. Sine curve force (20N-320N, 14Hz) was applied, and detorque values were measured after cyclic loading of 2 million times by loading machine. Detorque values of initial and after-loading were measured by digital torque gauge. One-way ANOVA was employed to see if there was any influence from different abutment heights. Results. The results were as follows: 1. The initial detorque value was 27.8$\pm$0.93 kgmm, and the ratio of the initial detorque value to the tightening torque was 0.91(27.8/30.5). 2. Measured detorque values after cyclic loading were declined as the height of the abutment increased, that was, 5.0 mm; 22.3$\pm$0.82 kgmm, 8.0 mm; 21.8$\pm$0.93 kgmm, and 11.0 mm; 21.3$\pm$0.94 kgmm. 3. One-way ANOVA showed no statistically significant differences among these (p>0.05). 4. Noticeable mobility at the implant-abutment interface was not observed in any case after cyclic loading at all.

• The Journal of Korean Academy of Prosthodontics
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• v.39 no.1
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• pp.71-83
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• 2001

The purpose of this study was to compare the effects of various surface treatments by measuring removal torque on bone healing around titanium implants. 40 Screw-shaped cp titanium implants with length of 4mm, outer diameter of 3.75mm, and pitch-height of 0.5mm were used Group 1 was left as machined(control), Group 2 was blasted with $50{\mu}m\;Al_2O_3$, group 3 was blasted and etched in etching solution($NH_4OH : H_2O_2:H_2O= 1 : 1 : 5$) at $90^{\circ}C$ for 1 minute group 4 was blasted and oxidated under pure oxygen at $800^{\circ}C$. The implant surface roughness was analyzed with SEM and CLSM(Confocal Laser Scanning Microscope) and implants were placed in proximal tibial metaphysis of 10 New Zealand White rabbits. After 3 months of healing period, removal torque of each implant was measured to compare bone healing around implant. The results obtained were as follows 1. In SEM view, blasting increased the roughness of the surface, but etching of that rough surface decreased the roughness due to the removal of the tip of the peak. Oxidation also decreased the roughness due to formation of needle-like oxide grains on the implant surface. 2. The Sa value from CLSM was least in the machined group($0.47{\mu}m$), greatest in blasted group($1.25{\mu}m$), and the value decreased after etching($0.91{\mu}m$) and oxidation($0.94{\mu}m$). 3. The removal torque of etched group(24.5Ncm) was greater than that of machined group(16.7Ncm) (P<0.05), and was greatest in the oxidated group(40.3Ncm) and the blasted group(34.7Ncm).

• The Journal of Korean Academy of Prosthodontics
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• v.42 no.3
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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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• v.34 no.1
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• pp.149-162
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• 2004

This study was performed to evaluate the effect of freeze-dried bone graft on space-making capacity and bone formation in the procedure of guided bone regeneration with titanium reinforced ePTFE membrane. After decortication in the calvaria, GBR procedure was performed on 8 rabbits with titanium reinforced ePTFE membrane filled with human FDBA(Rocky Mountain Tissue Bank,Aurora Co., USA). Decortication was performed to induce the effect of bone forming factor from bone marrow. The animals were sacrificed at 2 weeks, 4 weeks, 8 weeks and 12 weeks after the surgery. Non-decalcified specimens were processed for histologic analysis. πle results of this study were as follows: 1. Titanium reinforced-ePTFE membrane was biocompatable and capable of maintaining the space-making. 2. FDBA particle was surrounded with connective tissues but there was no evidence on new bone formation. 3. FDBA particle resorbed continuously but it remained until 12weeks after the surgery. Within the above results, TR-ePTFE membrane could be used effectively for Guided bone regeneration but It was assumed that FDBA does not appear to contribute to bone formation.

• Journal of Technologic Dentistry
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• v.34 no.2
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• pp.67-73
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• 2012

연구 목적: 임플란트의 하부구조를 상부 구조와 연결하는 레진시멘트의 접착강도를 높이기 위한 기계적 화학적인 표면처리 방법들이 연구 되고 있다. 이 연구에서 다양한 크기의 $Al_2O_3$ sandblasting과 Silano Pen으로 표면처리한 티타늄과 레진 시멘트의 접착강도를 알아보고자 한다. 연구 방법: 12개의 티타늄(Ti-6A1-4V)시편을 디스크 형태로 제작하여 자가중합 수지에 매립하였다. 이들을 각각 6개의 군으로 나누어 $50{\mu}m$, $90{\mu}m$, $110{\mu}m$ 등 3가지 크기의 $Al_2O_3$로 sandblasting 하는 조건과 $Al_2O_3$로 sandblasting한 후 Silano Pen(Bredent, bredent GmbH &Co.KG, Senden, Germany)을 사용한 군으로 나누었다. 표면처리 한 티타늄 표면에 레진시멘트(Duolink dual syringe, Bisco, USA)으로 접착하였다. 그 후 증류수($37^{\circ}C$)에 24시간 보관 후 접착강도 실험을 시행하였고, SEM을 사용하여 표면처리 한 표면과 접착강도 실험 후 파절양상을 관찰하였다. 결과: 통계학적 분석에 따르면 Silano Pen을 사용하여 표면처리한 군들의 접착강도가 높았다(P<0.05). 결론: Silano Pen을 사용하는 것이 티타늄과 레진시멘트의 접착강도를 증가 시킨다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2016.11a
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• pp.119-119
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• 2016

Over the last years the anodic formation of ordered $TiO_2$ nanotube layers has created significant scientific interest. Titanium oxide nanotube formation on the titanium or titanium alloy surface is expected to be important to improve cell adhesion and proliferation under clinical conditions. It should be possible to control the nanotube size and morphology for biomedical implant use by controlling the applied voltage, alloying element, current density, anodization time, and electrolyte. $TiO_2$ nanotubes show excellent biocompatibility, and the open volume in the tubes may be exploited as a drug release platform and so on. Therefore, in this study, Nanotube shape on the Ti-29Nb-xHf alloys with applied potentials was reserched. $TiO_2$ nanotube formation on Ti-29Nb-xHf alloys was carried out using anodization technique as a function of applied DC potential (10 V to 30 V and 30 V to 10 V) and anodization time for 60~120 min in $1MH_3PO_4$ with small additions of (0.8 wt. %, to 1.2 wt. %) NaF. The morphology change of anodized Ti-29Nb-xHf alloys was determined by FE-SEM, XRD, and EDS.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.5
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• pp.115-120
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• 2012

Metals used orthopedic in human magnetic resonance imaging scan of the metal to be inserted, The information to users about the image distortion is to propose a basis for judgment. Metals used orthopedic on Stainless, Titanium and Clip using ferromagnetic artifacts and distortion of the image were measured. Using Phantom "Effect of Metals used in Orthopedic on Magnetic Resonance ImagingI" pig in a paper subsequently was carried out using the same bone. Experimental results using a pure Titanium is a relatively high diagnostic value was found that.

• Journal of the Korean Society of Safety
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• v.23 no.6
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• pp.1-6
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• 2008

Machine operator and quality are affected by chip during cutting process to product machine parts. This paper presents a study of the influence of cutting conditions on the surface roughness obtained by turning using Taguchi method for safety of turning operator. In the machining of titanium alloy, high cutting temperature and strong chemical affinity between the tool and the work material are generated because of its low thermal conductivity and chemical reactivity. Therefore titanium alloys are known as difficult-to materials. An orthogonal array, the signal-to-noise ratio, the analysis of variance are employed to investigate the cutting characteristics of implant material bars using tungsten carbide cutting tools of throwaway type. Also Experimental results by orthogonal array are compared with optimal condition to evaluate advanced reliability. Required simulations and experiments are performed, and the results are investigated.

• The korean journal of orthodontics
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• v.36 no.4
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• pp.295-307
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• 2006

Objective: The purpose of this study was to compare the histological and biomechanical characteristics of self-tapping and self-drilling microscrew implants. Methods: 112 microscrew implants (56 self-drilling and 56 self-tapping) were placed into the tibia of 28 rabbits. The implants were loaded immediately with no force, light (100 gm), or heavy force (200 gm) with nickel-titanium coil springs. The animals were sacrificed at 3- and 5-weeks after placement and histologic and histomorphometric analysis were performed under a microscope. Results: All microscrew implants stayed firm throughout the experiment. There was no significant difference between self-drilling and self-tapping microscrew implants both in peak insertion and removal torques. Histologic examinations showed there were more defects in the self-tapping than the self-drilling microscrew implants, and newly formed immature bone was increased at the interface in the self-tapping 5-week group. There was proliferation of bone towards the outer surface of the implant and/or toward the marrow space in the self-drilling group. Histologically, self-drilling microscrew implants provided more bone contact initially but the two methods became similar at 5 weeks. Conclusion: These results indicate the two methods can be used for microscrew implant placement, but when using self-tapping microscrew implants, it seems better to use light force in the early stages.