• 대한치과보철학회지
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• 제35권2호
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• pp.277-295
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• 1997

After clinical adjustment of dental casting restoration, re-polishing procedure is recommanded because the smooth gold sureface is lost. But there is the possibility to get more loose contact than that intended by loss of gold alloy according to the kinds of polishing materials and polishing time. Therefore in this study I polished type II gold alloy with 390gm force, 20,000rpm speed, and 8 kinds of gold alloy polishing materials, fabricated by 4 companies and then measured the amount of loss of gold alloy with Surfcorder SEF-30D and observed alloy surfaces polished by 3 brown rubber points with SEM. The amount of loss of gold alloys polished with 8 kinds of polishing materials and the degree of smoothness of gold alloys according to polishing time and polishing materials were compared. The following results were obtained : 1. When the amount of loss of gold alloys polished with 3 kinds of brown rubber point was compared, Alphalex brown point had the most amount of alloy loss, followed in decreasing order by Shofu brown point and Eveflex brown point. There was statistically significant difference in the amount of alloy loss according to polishing materials. 2. When the amount of loss of gold alloys polished with 5 kinds of green rubber point was compared, Shofu green point had the most amount of alloy loss, followed in decreasing order by Alphaflex green point, Dedeco green clasp polisher, and Eveflex green point. There was statistically significant difference in the amount of alloy loss according to polishing materials except Alphaflex green point and Dedeco green clasp polisher. 3. When the amount of loss of gold alloys polished with all kinds of rubber point was compared, there was no significant difference in Eveflex brown point, Alphaflex green point, and Dedeco green clasp polisher. 4. When average amount of alloy loss per 1 revolution by polishing materials was compared, Alphalex brown point had the greatest value as $0.329{\mu}m$ and Shofu supergreen point had the lowest value as $0.022{\mu}m$. 5. When the degree of sureface smoothness of gold alloy polished with 3 kinds of brown rubber point was compared, In Alphalex brown point surface roughness was completely lost after 20 seconds polishing time, in Shofu brown point 30 seconds, in Eveflex brown point 40 seconds. But in every gold alloys fine scratch formed by rubber points was observed. Based on the results of this study, as rubber polishing materials used in polishing of dental casting restoration after clinical adjustment influenced on the tightness of occlusal or proximal contact, we should make dental casting restoration with minimum error through careful laboratory procedure and form very smooth surface of restoration with tripoli and rouge after use of silicone polishing materials.

• Archives of Plastic Surgery
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• 제37권1호
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• pp.37-45
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• 2010

Purpose: In Korean rhinoplasty, alloplasts such as silicone rubber have been used for dorsal and tip augmentations. However, alloplasts have produced complications such as deviation, exposure, and infection. Although autogenous tissue is an ideal material, the amount of the cartilage in Korean is not sufficient. Therefore, the authors developed a method to harvest the maximum amount of the septal and conchal cartilage. The authors first performed a complete septal extension graft for short and retruded columella and then performed nasal augmentation using various autogenous tissues. Methods: These surgical techniques were performed on 11 patients. Their average age was 27 years. An open approach with a V-shaped columellar labial incision was performed. At first, the complete septal extension graft was fixed on the entire caudal margin of the septum, and the alar cartilage was suspended to the septal extension graft to make the tip projected and the columella advanced caudally. A temporal fascial ball was used for radix augmentation. For dorsal augmentation, a batten-shaped septal cartilage graft wrapped with or without the temporal fascia or a diced cartilage graft wrapped with the temporal fascia was performed. For nasal tip augmentation, a shield graft and a cap graft or a folded conchal cartilage graft was performed.Results: The mean follow-up period was 11.2 months. The overall results were natural and satisfactory. Two patients underwent slight absorption and caudal displacement. With the exception of these cases, no complications were observed. Conclusion: Korean rhinoplastic surgeons are accustomed to using the alloplasts despite of serious complications. When rhinoplasty using autogenous tissue was performed, some complications occurred such as the displacement of the diced cartilage graft wrapped with the fascia, but many of the complications of alloplastic rhinoplasty were avoided. Therefore, we propose that by this time Korean rhinoplastic surgeons need to change their preference from alloplastic rhinoplasty to autogenous rhinoplasty.

• Archives of Plastic Surgery
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• 제36권4호
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• pp.437-444
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• 2009

Purpose: Transgender is a disorder of gender identity, who have appropriate chromosomal, hormonal and anatomical characteristics corresponding to their sexual phenotype but feel strongly with respect to their sexual identity, that they belong to the opposite sex. There is a persistence discomfort and sense of inappropriateness about one's assigned sex in a person who has reached puberty. Transgender is a psychiatric problem, but surgical method provides more satisfactory adjustment for patients. In gender reassignment surgery for female to male transgender, mastectomy, nipple reduction, hysterectomy, oophorectomy and phalloplasty are included. And as the final operation, recommended for scrotoplasty and artificial testes insertion. So we investigated the necessity and method of scrotoplasty in the final operation of female to male transgender. Method: The authors have long term follow-up of 75 cases female to male transgender during January, 1991 to February, 2008. Among them, 13 cases were evaluated in this study. During phalloplasty, the labium major skin preserved. And this labium majoral skin flap was made for the neoscrotum. At least six months later, artificial testes were inserted in neoscrotum with local anesthesia. Middle sized (3 cm diameter) artificial testes(silicon gel or carving soft silicone implant) were used because of the limitation of the neoscrotum. We evaluated the questionnaire and interview about the postoperative satisfaction in configuration of reconstructed scrotum, and the necessity of operation, the postoperative psychosocioeconomic improvement and limitation of body exposure activities such as swimming, public bathing. Results: Based on this study, satisfaction of reconstructed scrotum after scrotoplasty was improved(92%). The necessity of scrotoplasty was in 92.3% and the postoperative psychosocioeconomic well - being improvement was 77% in answers. Less limitation of activities requiring body exposure was 54% in answers. Most of the patients were satisfied with the results of surgical operation inspite of the operative procedure had some postoperative complications. Conclusion: This study was reported that the scrotoplasty in female to male transgender is not only a conversion of external genitalia but also an improvement of psychosocial state. Most patients sincerely hope to this operation, so we improve our surgical method for more good results.

• 한국방사선학회논문지
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• 제14권2호
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• pp.149-155
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• 2020

방사선 방호복의 대부분은 가공성과 경제성이 매우 우수하고 높은 원자번호를 갖고 있어 방사선 차폐가 우수한 납으로 제작된다. 하지만 납은 유해 중금속으로 분류되어 납중독 등의 위험이 있으며, 착용 시 중량감 및 불편함 등이 크므로 최근에는 납이 아닌 다양한 물질로 차폐 시트에 대한 연구가 이루어지고 있다. 본 연구에서는 인체에 무해한 BaSO₄와 Bi₂O₃두 화합물과 실리콘 재질의 바인더를 혼합하여 기존과 동등한 방사선 차폐능력을 유지하면서도 물리적 특성이 개선된 다층 구조의 차폐 시트에 대한 연구를 수행하였다. 연구 결과 기존의 차폐 시트와 비교하여 본 연구에서 제작된 다층 구조의 방사선 차폐 시트는 동일한 두께를 기준으로 약 9.8 % 우수한 특성을 보였으며 물리적 특성 중 인장 강도는 BaSO₄/nylon/Bi₂O₃ 차폐 시트에서 12.27 N/㎟로 가장 우수한 것으로 분석되었다.

• Archives of Plastic Surgery
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• 제40권5호
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• pp.610-615
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• 2013

Background Cephalometric analysis is essential for planning treatment in maxillofacial and aesthetic facial surgery. Although photometric analysis of the Korean nose has been attempted in the past, anthropometry of the deeper nasal structures in the same population based on computerized tomography (CT) has not been published. We therefore measured three anthropometric parameters of the nose on CT scans in our clinical series of patients. Methods We conducted the current retrospective study of a total of 100 patients (n=100) who underwent a CT-guided radiological measurement at our institution during a period ranging from January of 2008 to August of 2010. In these patients, we took three anthropometric measurements: the nasofrontal angle, the pyramidal angle, and the linear distance between the nasion and the tip of the nasal bone. Results The mean nasofrontal angle was $131.14^{\circ}$ in the male patients and $140.70^{\circ}$ in the female patients. The mean linear distance between the nasion and the tip of the nasal bone was 21.28 mm and 18.02 mm, respectively. The mean nasal pyramidal angle was $112.89^{\circ}$ and $103.25^{\circ}$ at the level of the nasal root, $117.49^{\circ}$ and $115.60^{\circ}$ at the middle level of the nasal bone, and $127.99^{\circ}$ and $125.04^{\circ}$ at the level of the tip of the nasal bone, respectively. Conclusions In conclusion, our data will be helpful in the preparation of silicone implants for augmentation and/or corrective rhinoplasty in ethnic Korean people.

• 한국재료학회지
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• 제14권12호
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• pp.893-899
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• 2004

Even though Ti-6Al-4V has gained popularity as an implant material, the possible dissolution of Al and V ions in body fluids remains a matter of concern. Though commercially pure Ti (Cp-Ti) overcomes this problem, the mechanical strength of pure titanium remains very low. Thus, in this experiment Cp-Ti was processed by Equal channel angular processing (ECAP), in order to increase the mechanical strength. The biocompatibility of ECAP-Ti, Cp-Ti and Ti-6Al-4V was examined by the apatite formation on each sample surface, after treating the surface with 5M NaOH and soaking in Simulated body fluids (SBF). Initially, the samples were mechanically polished on silicone carbide paper (#2000). The polished samples were treated with 5M NaOH solution at $60^{\circ}C$ for 24 hours. The NaOH treated samples were washed gently with distill water and dried at $40^{\circ}C$ for 1 day. The dried samples were heat treated in air at $600^{\circ}C$ for 1 hour. The surface morphology of these samples were studied using SEM and XRD. The SEM studies showed network of pores in all samples. The XRD showed oxide layer formation on Cp-Ti and Ti-6Al-4V. samples. However the oxide layer in ECAP-Ti was not substantial. These samples were immersed in SBF, kept at $36.5^{\circ}C$ for seven days period. At the end of 7 days, the apatite formation was confirmed only on Cp-Ti and was not observed in Ti-6Al-4V and ECAP-Ti. These observations of apatite formation relate to the fact that Cp-Ti showed greater oxide layer than other samples. The apatite examined was confirmed as tricalcium phosphate (TCP) using EDS and XRD.

• Restorative Dentistry and Endodontics
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• 제22권1호
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• pp.396-412
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• 1997

The purpose of this study is to observe the corrosion characteristics of five dental amalgams(CAULK FINE CUT, OPTALLOY II, DISPERSALLOY, TYTIN, and VALIANT) in the solutions with fluoride compound through the anodic polarization curve obtained by using a potentiostat. After each amalgam alloy and Hg being triturated, the triturated mass was inserted into the cylindrical metal mold, and condensed by hydraulic pressure(160 kg/$cm^2$). Each specimen was removed from the metal mold. Specimens were polished with the silicone carbide grinding paper 24 hours after condensation and stored at room temperature for 1 week. The anodic polarization curves were employed to compare the corrosion behaviours of the amalgams in 0.9 % saline solution and in the saline solutions with 2.2 ppm, 0.05 %, 2 % NaF, and 8 % $SnF_2$ at $37^{\circ}C$ with 3-electrode potentiostat. After the immersion of specimen in electrolyte for 30 minutes, the potential scan was begun. The potential scan range was -1500m V to + 800m V(vs. S.C.E.) in the working electrode and the scan rate was 50 mV/sec. The results were as follows, 1. The corrosion potential, the potential of anodic current peak, and transpassive potential in the saline solutions with NaF shifted to lower direction than those in normal saline solution, and the current density in the saline solutions with NaF was higher than that in normal saline solution. The differences were increased as the concentrations of NaF became higher. 2. The corrosion potential and transpassive potential in the saline solution with $SnF_2$ shifted to higher direction than those in normal saline solution, and the current density in the saline solution with $SnF_2$ was higher than that in normal saline solution after the corrosion potential. The anodic polarization curves in the saline solution with $SnF_2$ had no outstanding anodic current peak. 3. The corrosion potentials for high-copper amalgams were much higher than those for CAULK FINE CUT and OPTALLOY II in normal saline solution, but, as the concentrations of fluoride compound became higher, the differences in corrosion potentials between them were decreased. The corrosion potentials had the similarity in the saline solution with 2% NaF or 8% $SnF_2$. 4. The current density for TYTIN was the lowest among the others in normal saline solution and in the saline solution with 2.2 ppm or 0.05 % NaF. 5. There was no significant difference in current density between Pd-enriched VALIANT and other high-copper amalgams.

• 대한화장품학회지
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• 제36권3호
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• pp.227-231
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• 2010

파우더 파운데이션은 사용이 간편하고 수정화장이 용이하여 고객들이 많이 사용하고 있으며, 파우더 파운데이션을 만드는 방법은 건식방식, 소성방식, 그리고 습식방법으로 크게 분류할 수가 있다. 이 중 습식방법은 이미 잘 알려진 바와 같이 back injection 방법과 front injection 방법이 있으며, 본 논문에서는 front injection 방법을 사용해 실험을 진행하였다. 실험결과 용매의 종류에 따른 경도 변화를 살펴보면 휘발성 실리콘이나 탄화수소계 휘발성 물질을 이용할 때 보다 정제수를 이용할 때 경도가 높게 나타났으며, 사용감 측면에서는 물보다는 탄화수소계 휘발성 물질과 휘발성 실리콘 등을 사용했을 때, 고객 선호도가 높게 나타났다. 또한 코팅물질 변화에 따른 경도 변화로는 아미노산계 코팅물질을 사용하였을 때 경도가 상승하는 효과를 나타냈으며, 실리콘 코팅 물질을 사용했을 때 경도 상승효과가 미비한 것으로 나타났다. 이러한 결과를 토대로 각 대상 고객에 맞는 처방을 개발하고자 할 때 사용감과 경도의 상관관계를 알고, 처방설계에 이용한다면 고객이 원하는 사용감에 한발 더 접근할 수 있으리라 생각된다.

• 치위생과학회지
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• 제15권2호
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• pp.226-231
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• 2015

본 연구는 세 가지 종류 스캐너에 따른 정확도를 비교 평가하기 위하여 시행되었다. 경석고 모형과 스캐너로 채득한 디지털 모형에 각 4지점씩 계측지점을 선정하였고, 이들 4지점사이를 DVC와 디지털 모형 측정 프로그램을 이용하여 길이를 측정하고, 다음과 같은 결론을 도출하였다. 세 가지 종류의 스캐너 가운데 레이저 스캐너가 백색광 스캐너나 청색광 스캐너보다 높은 정확도를 나타내었으나 이 세 가지 종류의 스캐너 모두가 임상적으로 사용하는 것이 가능하다.

• Restorative Dentistry and Endodontics
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• 제22권2호
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• pp.751-760
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• 1997

Resin-modified glass ionomers were introduced in 1988 to overcome the problems of moisture sensitivity and low early mechanical strengths of the conventional glass ionomers, and to maintain their dinical advantages. The purpose of this study was to evaluate the bi-axial fracture strength of four resinmodified glass-ionomers(Fuji II LC, Vitremer, Dyract, VariGlass), one resin composite material(Z-100), and one conventional glass-ionomer(Fuji II). Three specimens of each material and shade combination were made according to the manufacturers' instructions. Materials were condensed into metal mold with a diameter of 10mm and a thickness of 2.0mm and pressed between two glass plates. Resin-modified glass ionomers were polymerized using a Visilux II light curing unit by irradiating for 60 seconds from both sides, and conventional glass ionomer was cured chemically. After specimens were removed from the molds, surfaces were polished sequentially on wet sandpapers up to No. 600 silicone carbide paper. The specimens were thermocycled for 2,000 cycles between $5^{\circ}C$ and $55^{\circ}C$ distilled water. After thermocycling, bi-axial fracture strengths were measured using a compressive-tensile tester(Zwick 1456 Z020, Germany) with the cross head speed of 0.5mm/minute. The results were as follows: 1. Two factors of the kind and color of materials had a main effect on bi-axial fracture strength (p<0.01), and bi-axial fracture strength was influenced significantly by the kinds of materials (p<0.01). But there was no significant interaction between two variables of the kind and color of materials (p>0.05). 2. Comparing the mechanical properties of the materials, the elastic modulus of Z100 was higher than any other material, and there was no difference in the displacement at fracture among materials. The bi-axial fracture strength of Z100 was significantly higher than any other material, and that of resin-modified glass ionomers was significantly higher than that of conventional glass ionomer (p<0.05). 3. In the same material group, the color of material had little influence on the mechanical properties.