• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.17-18
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• 2010

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.3
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• pp.206-213
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• 2011

Purpose: The aim of this study was to evaluate the clinical value of Osstem$^{(R)}$ USII plus system implants. Clinical and radiographic data were analyzed for 88 implants placed and functionally loaded for a 12 month period at the Yonsei University Dental Hospital. Materials and Method: Based on the patient's medical records, clinical factors and their effects on implant marginal bone resorption, distribution and survival rate were analyzed. The marginal bone loss was evaluated at implant placement and during a 6 to 12 months functional loading period. The independent sample t-test was used to evaluate the interrelationship between the factors (${\alpha}$=0.05), and one way repeated measures ANOVA was used to compare the amount of marginal bone resorption. Results: The cumulative survival rate for 88 implants was 100%. The marginal bone resorption from implant placement to prosthetic delivery was 0.24 mm and the average marginal bone resorption from prosthetic delivery to 12 months of functional loading was 0.19 mm. The total average bone resorption from implant placement to 12 months of functional loading was 0.43 mm. There were no statistically differences in the amount of marginal bone resorption when implants were placed in the maxilla or the mandible (P>.05), however, implants placed in the posterior areas showed significantly more marginal bone loss than those placed in the anterior areas (P<.05). Conclusion: Based on these results, the short term clinical success rate of RBM surface treated external connection domestic implants showed satisfactory results and the marginal bone loss was in accord with the success criteria of dental implants.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.3
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• pp.319-326
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• 2012

For many years, ceramics have been used in fixed prosthodontics for achieving optimal esthetics. but, they have another use as well. Many studies today show ceramics can be used for biomaterials. In the beginning researchers made a start in the study of aluminium oxide and sapphire for biomaterial. The appearance of Zirconia began a new phase of research. Zirconia was introduced into implantology as an alternative to titanium, because of its white color, good mechanical properties and superior biocompatibility. But it is not easy to surface treatment in comparison with titanium. To overcome the limitation, interconnected porous bodies of zirconia were fabricated by sintering technique. And the technique of coating was developed. Therefore, some zirconia implants are currently available. It is thought that Research of biomaterials as a variety of puposes for the use of zirconia is looking very promising. The purpose of this paper reviews are to evaluation of zirconia as biomaterials.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.05a
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• pp.47.2-47.2
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• 2009

인체의 뼈와 같은 손상된 경조직을 치료 또는 대체하기위한 정형외과용 임플란트를 설계하는데 있어 뼈의 생체역학적 특성과 유사한 성질을 갖는 다공성 지지체에 대한 연구가 최근 관심을 끌고 있다. 다공성 지지체는 조직이 원활히 재생될 수 있어야 하며, 또한 주변 조직과도 생물학적인 고착이 잘 되도록 기공들이 상호 연결된 구조를 가져야 한다. 이와 같은 다공성 지지체용 소재를 제조하기 위하여 본 연구에서는 타이타늄 분말을 사용하여 3차원 적층조형공정으로 다공성 타이타늄 지지체를 제조하였다. 제조된 다공체의 물성 및 기계적 특성을 평가하기 위하여 압축시험과 변형해석을 수행하였으며, 아울러 제조된 지지체의 생체적합성 향상을 위하여 양극산화 공정 등의 표면처리를 수행하여 그에 대한 특성을 평가하였다. 분말야금 공정으로 제조된 지지체는 골조직의 성장에 적합한 약 $300\sim400{\mu}m$의 기공 크기를 갖도록 제어하였고, 기공도는 60~75%로 제어하였다. 아울러 다공성 타이타늄의 생체적합성을 부여하기 위하여 양극산화공정으로 지지체의 표면에 Ca 및 P을 포함하는 산화층을 형성시키는 표면처리를 수행하였다. 양극산화공정에 의하여 표면에 미세기공을 포함하는 산화층을 형성시킬 수 있었으나 이와 같은 표면구조는 조골세포의 부착과 영향에는 큰 영향을 미치지 않는 것으로 확인되었다.

• Journal of Dental Rehabilitation and Applied Science
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• v.30 no.4
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• pp.278-288
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• 2014

Purpose: The aim of the study was to evaluate preprosthetic initial survival rate and factors associated with survival of osseointegrated implants placed in edentulous area of maxilla and mandible and to suspect the possible causes leading to failure. Materials and Methods: A total of 2158 endosseous implants that had been inserted between 2004 through 2013 were placed in 770 patients. The clinical comparisons were performed to evaluate implant loss in relation to age and gender of patients, position, system, length and diameter of implant, and bone graft technique. Results: According to position, the survival rates were 98.23% in maxillary anterior site, 96.98% in maxillary posterior site, 97.85% in mandibular anterior site and 98.76% in mandibular posterior site (P < 0.05). According to diameter of implant, the survival rates were 100% under 3.0 mm, 97.09% between 3.0 to 3.5 mm, 98.19% between 3.5 to 4.0 mm and 98.29% between 4.0 to 4.5 mm but relatively lower survival rate was 75% in 5.0 mm-over (P < 0.05). The survival rates of implants were 89.51%, 98.28%, 98.34% and 99.27% in the group with isolated sinus graft, with isolated GBR, with sinus graft and GBR simultaneously and without bone graft, especially (P < 0.05). Conclusion: This study establishes a relationship between survival rate of implant and position, diameter of implant system and bone graft technique. In conclusion, there were low survival rates in maxillary posterior site, in dental implants with wide diameter of 5 mm-over, and in the group with isolated sinus graft.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2013.05a
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• pp.215-215
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• 2013

임플란트 소재로서 순 타이타늄은 높은 응력이 발생하는 부위에는 그 강도가 충분하지 않은 것으로 지적되었으며, 이러한 이유로 인해서 그의 대용합금에 대한 연구가 진행되고 있다. 본 연구에서 ${\beta}$형 타이타늄 합금 Ti-32Nb-5Zr 합금을 시험재료로 선택한 다음 양극산화와 석회화 순환처리에 의해서 표면을 개질한 결과, HAp 석출이 빠르게 가속되었을 뿐만 아니라 신생골 생성량과 골결합력이 크게 개선된 결과를 보여주었다.

• Journal of Dental Rehabilitation and Applied Science
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• v.25 no.4
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• pp.361-374
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• 2009

For successful osteogenesis around the implants, interaction between implant surface and surrounding tissue is important. Biomechanical bonding and biochemical bonding are considered to influence the response of adherent cells. But the focus has shifted surface chemistry. The purpose of this study is to evaluate the MC3T3-E1 osteoblast like cell responses of magnesium (Mg) ion implanted titanium surface produced using a plasma source ion implantation method. Commercially pure titanium disc was used as substrates. The discs were prepared to produce four different surface, A: Machine turned surface, B: Mg implanted surface, C: sandblasted surface, D: sandblasted and Mg implanted surface. MC3T3 El osteoblastic like cells were cultured on the disc specimens. Cell adhesion, proliferation, differentiation, and synthesis of extracellular matrix were evaluated. The cell adhesion morphology was evaluated by SEM. RT PCR assay was used for assessment of cell adhesion, proliferation and differentiation. ALP activity was measured for cell differentiation. The results of this study were as follows: 1. SEM showed that cell on Mg ion groups was more proliferative than that of non Mg ion groups. On the machine turned surface, cell showed some degree of contact guidance in aligning with the machining grooves. 2. In RT PCR analysis, osteonectin and c-fos mRNA were more expressed on sandblasted and Mg ion implanted group. 3. ALP activity was not significantly different among all groups. Within the limitations of this study, the following conclusions were drawn: It might indicate Mg ion implanted titanium surface induce better bone response than non Mg ion groups.

• Korean Journal of Dental Materials
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• v.45 no.4
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• pp.257-274
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• 2018

The purpose of this study was to evaluate the effect of acid-treatment conditions on the surface properties of the RBM (Resorbable Blast Media) treated titanium. Disk typed cp-titanium specimens were prepared and RBM treatments was performed with calcium phosphate ceramic powder. Acid solution was mixed using HCl, $H_2SO_4$ and deionized water with 4 different volume fraction. The RBM treated titanium was acid treated with different acid solutions at 3 different temperatures and for 3 different periods. After acid-treatments, samples were cleaned with 1 % Solujet solution for 30 min and deionized water for 30 min using ultrasonic cleanser, then dried in the electrical oven ($37^{\circ}C$). Weight of samples before and after acid-treatment were measured using electric balance. Surface roughness was estimated using a confocal laser scanning microscopy, crystal phase in the surface of sample was analyzed using X-ray diffractometer. Surface morphology and components were evaluated using Scanning Electron Microscope (SEM) with Energy Dispersive X-ray spectroscopy (EDX) and X-ray Photoemission Spectroscopy (XPS). Values of the weight changes and surface roughness were statistically analyzed using Tukey-multiple comparison test (p=0.05). Weight change after acid treatments were significantly increased with increasing the concentration of $H_2SO_4$ and temperature of acid-solution. Acid-treatment conditions (concentration of $H_2SO_4$, temperature and time) did not produce consistent effects on the surface roughness, it showed the scattered results. From XRD analysis, formation of titanium hydrides in the titanium surface were observed in all specimens treated with acid-solutions. From XPS analysis, thin titanium oxide layer in the acid-treated specimens could be evaluated. Acid solution with $90^{\circ}C$ showed the strong effect on the titanium surface, it should be treated with caution to avoid the over-etching process.

• Journal of dental hygiene science
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• v.16 no.1
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• pp.70-76
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• 2016

The objective of this study was to fabricate hydroxyapatite (HA) containing titania layer by HA blasting and anodization method to obtain advantages of both methods and evaluated biocompatibility. To fabricate the HA containing titania layer on titanium, HA blasting treatment was performed followed by microarc oxidation (MAO) using the electrolyte solution of 0.04 M ${\beta}$-glycerol phosphate disodium salt n-hydrate and 0.4 M calcium acetate n-hydrate on the condition of various applied voltages (100, 150, 200, 250 V) for 3 minutes. The experimental group was divided according to the surface treatment procedure: SM (simple machined polishing treatment), HA, MAO, HA+MAO 100, HA+MAO 150, HA+MAO 200, HA+MAO 250. The wettability of surface was observed by contact angle measurement. Biocompatibility was evaluated by cell adhesion, and cell differentiation including alkaline phosphatase activity and calcium concentration with MC3T3-E1 cells. The porous titanium oxide containing HA was formed at 150 and 200 V. These surfaces had a more hydrophilic characteristic. Biocompatibility was demonstrated that HA titania composite layer on titanium showed enhanced cell adhesion, and cell differentiation. Therefore, these results suggested that HA containing titania layer on titanium was improved biological properties that could be applied as material for dental implant system.

• Journal of Dental Rehabilitation and Applied Science
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• v.37 no.4
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• pp.259-267
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• 2021

Peri-implantitis, in which inflammation caused by plaque and biofilm on the implant surface spreads to the hard tissue, can be treated by decontamination of the implant surface and reconstruction of the lost hard tissue through surgical methods. We have described the management of 3 peri-implantitis cases by decontamination of the implant surface using a round titanium brush and regenerative therapy. All cases showed clinical improvements, and no further radiographic bone loss was observed during a 2-year follow-up. This treatment method can be effective for clinical improvement and bone regeneration. However, a longer follow-up period is necessary to support these outcomes.