• Journal of Oral Medicine and Pain
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• 제30권1호
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• pp.131-140
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• 2005

이 연구의 목적은 어븀 야그 레이저의 상아질과 법랑질에서의 절삭율을 조사하고 레이저 절삭후의 형성된 와동의 미세구조적 변화를 전통적인 핸드피스 드릴을 이용한 와동의 미세구조적 변화와 비교하기 위함이다. 사용된 어븀 야그 레이저는 20 Hz, 15 Hz의 주파수에서 200 mJ, 250 mJ, 300 mJ의 에너지 레벨로 나누어 조사하였다. 다음과 같은 결과가 얻어졌다. 1. 3 W-6 W의 에너지 세기로 조사한 상아질 그룹에서의 절삭율은 약 $1.103{\sim}2.639mm^3/sec$ 이었고 4.5 W$\sim$6 W의 에너지 세기에서는 유의한 절삭율의 차이가 없었다. 2. 3 W-6 W의 에너지 세기로 조사한 법랑질 그룹에서의 절삭율은 약 $0.413{\sim}0.969mm^3/sec$ 이었고 4 W$\sim$6 W의 에너지 세기에서는 유의한 절삭율의 차이가 없었다. 3. 전통적 고속핸드피스 드릴로 삭제된 와동을 주사전자현미경으로 관찰한 결과 도말층으로 덮인 비교적 편평한 표면을 보였다. 4. 레이저로 삭제된 상아질 와동을 주사전자현미경으로 관찰한 결과 도말층이 없으며 상아세관이 열려있는 것이 관찰되었다. 하지만 3 W 이상의 에너지 세기로 조사한 와동에서는 표면이 불규칙하며 파편들이 헐겁게 붙어있는 것이 관찰되었다. 5. 레이저로 삭제된 법랑질 와동을 주사전자현미경으로 관찰한 결과 심하게 파괴된 면이 6 W에서 보였으며 3 W의 에너지 세기에서는 용융된 구상물질이 관찰되었다. 하지만 4 W의 에너지 세기로 조사한 그룹에서는 깨끗하게 절삭된 면이 관찰되었다. 따라서 어븀야그 레이저를 이용하여 치아를 삭제할 때에 가장 효과적이며 열적 손상을 줄일 수 있는 에너지 세기는 상아질에서는 3 W, 법랑질에서는 4 W가 될 수 있을 것이다. 하지만 더 많은 연구와 추가적인 자료들이 필요할 것으로 사료된다.

• Restorative Dentistry and Endodontics
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• 제35권2호
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• pp.134-142
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• 2010

이 연구의 목적은 상아질 지각과민증 모드의 Er,Cr:YSGG 조사가 복합레진 수복물의 미세인장 결합강도에 미치는 영향을 평가하는 것이다. 20개의 발거된 대구치를 사용하여 Er,Cr:YSGG 레이저 적용 유무와 사용된 접착제 시스템(Optibond FL과 Clearfil SE bond), 산의 적용 시간(15초와 20초)에 따라 여섯 그룹으로 나누었다. 노출된 교합면 상아질에 레이저 조사 후 접착제를 도포하고 복합레진으로 수복하였다. 24시간 동안 실온의 증류수에 보관 후 각 그룹 당 12개의 시편을 준비하였다. 모든 시편의 미세인장 결합강도를 측정하고 파절 양상을 관찰하였다. 더불어 레이저를 조사한 시편과 조사하지 않은 시편을 주사현미경을 이용하여 관찰하여 다음과 같은 결과를 얻었다. 1. 레이저를 조사한 그룹은 레이저를 조사하지 않은 그룹보다 낮은 미세인장 결합강도를 나타내었다. 2. 레이저 조사 유무와 관계없이, Optibond FL이 Clearfil SE bond보다 높은 미세인장 결합강도를 나타냈으며, Optibond FL을 사용했을 때 산부식 시간이 20초인 경우가 15초인 경우보다 더 높은 값을 나타내었다. 3. 레이저를 조사한 상아질의 SEM 사진은 관간상아질보다 관주상아질이 더 두드러져 보이며, 상아세관이 열려있으며 도말층은 관찰되지 않았다.

• Restorative Dentistry and Endodontics
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• 제32권4호
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• pp.327-334
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• 2007

이 연구는 서로 다른 카바이드 버와 다이아몬드 버로 5급 와동을 형성 한 후 SE primer 접착 시스템인 Clearfil SE Bond를 이용한 복합레진 수복 시 버의 종류에 따른 법랑질과 상아질 변연에서의 미세누출 차이를 상호 비교하기 위하여 시행하였다. 4종의 삭제기구를 이용하여 각각 10개의 발거된 대구치의 협면 치경부에 5급 와동을 형성하였다. 1군은 plain-cut carbide fissure bur (no. 245)를 사용한 군, 2군은 cross-cut carbide fissure bur (no. 557)를 사용한 군, 3군은 fine diamond bur (TF-21F: 입자크기 $53\;-\;63\;{\mu}m$)를 사용한 군, 4군은 standard diamond bur (EX-41: 입자크기 $106\;-\;205\;{\mu}m$)를 사용한 군으로 분류하였다. 형성된 와동에 Clearfil SE Bond의 Primer와 Bond를 적용하고 Clearfil AP-X 복합레진을 충전하여 광중합한 후, Sof-Lex disc를 이용하여 마무리와 연마를 시행하였다. 수복된 치아를 2% methylene blue 용액에 24시간 동안 침적시킨 후 각 군의 치아를 협설로 절단하여 광학 입체현미경 하에서 법랑질과 상아질 변연에서의 미세누출 점수를 평가하여 다음과 같은 결과를 얻었다. Clearfil SE Bond와 복합레진을 이용한 5급 와동 수복 시 거친 다이아몬드 버의 사용은 카바이드 버나 미세한 다이아몬드 버에 비해 법랑질과 상아질 변연 모두에서 높은 미세누출을 나타내었다.

• Parasites, Hosts and Diseases
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• 제58권2호
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• pp.195-200
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• 2020

Soil-transmitted helminths, including Ascaris lumbricoides and Trichuris trichiura, are important intestinal parasites mostly affecting younger people in developing countries. In 2014-2015, we performed mass fecal examinations targeting a total of 2,227 schoolchildren in 3 districts (South Dagon, North Dagon, and Hlaing-thar-yar) of Yangon Region, Myanmar, using the Kato-Katz thick smear technique. The egg positive children were subjected to a mass drug administration (MDA) using a single oral dose of 400 mg albendazole. The pre-treatment egg positive rate (EPG/person) of A. lumbricoides averaged 17.2% (15,532); it was 25.2% (21,796), 14.2% (11,816), and 12.8% (12,983) in 3 districts, respectively, and that of T. trichiura averaged 19.4% (1,074), and was 24.1% (1,040), 12.3% (852), and 21.2% (1,330) in 3 districts, respectively. Follow-up fecal examinations performed 4 months post-MDA revealed considerable decreases of A. lumbricoides prevalence (EPG/person) to av. 8.3% (12,429), and 13.7% (17,640), 8.0% (7,797), and 4.5% (11,849) in 3 districts, respectively. However, T. trichiura did not show any recognizable decrease in the prevalence (EPG/person) remaining at av. 18.2% (862), and 18.5% (888), 11.5% (812), and 23.3% (887) in 3 districts, respectively. The results demonstrated difficulty in short-term control of T. trichiura by MDA using albendazole and suggested necessity of either a long-term MDA (>10 years) or changing the albendazole regimen into 2~3-day course (total 800 or 1,200 mg), or using an alternative drug/drug combination.

• Radiation Oncology Journal
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• 제19권2호
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• pp.142-145
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• 2001

목적 : 극심한 백혈구 증가증($10^5/mm^3$ 이상)을 동반한 급성 백혈병은 뇌내 출혈로 인한 조기 급사의 위험이 높은 질환이다. 응급 전두개 방사선조사는 비교적 단순하게 이 문제에 대처할 수 있는 방법으로 본 저자들은 24명의 극심한 백혈구 증다증을 보인 환아에서의 전두개 방사선 치료의 경험을 보고하고자 한다. 대상 및 방법 : 1990년부터 1998년까지 40명의 극심한 백혈구 증가증을 보이는 급성 백혈병 환아가 응급 전두개 방사선 조사를 위해 의뢰되었다. 이들중 24명의 환아의 초기 병록의 검색이 가능하였다. 환자군은 남아가 16명, 여아가 8명이었으며 연령 분포는 2세에서 13세(중앙값 9.5세) 였다. 초기의 백혈구 수치는 $109,910/mm^2$ 에서 $501,111/mm^2$의 범위에 있었다. 모든 환자에게 말초 혈액 도말 검사를 시행하였고 응급 전두개 방사선조사는 백혈구 수치가 $10^5/mm^2$ 이상이며, 말초 혈액에서 림프구모세포가 관찰된 환자들에게 시행되었다. 모든 환자는 염기성 전해질을 포함한 정맥 수액요법과 경구 allopurinol 복용의 처치를 받았다. 전두개 방사선 조사는 진단일로부터 시작되었으며 2Gy의 분할 조사선량으로 1회 시행받은 환아가 4명, 2회 시행받은 환아가 20명이었다. 결과 : 백혈구 수는 19명의 환아에게서 감소를 나타냈으며 방사선조사 후 뇌내 출혈은 관찰되지 않았다. 5례의 조기 사망이 있는데 4례는 대사적 합병증과 관련된 것이었고 1례는 방사선조사 전에 일어난 뇌내 출혈로 인한 사망으로 방사선조사 5시간 후에 사망하였다. 전두개 방사선조사 후에 즉각적인 부작용은 관찰 되지 않았다. 결론 : 이상의 결과에서 극심한 백혈구 증가증을 보이는 소아 백혈병 환자에게 응급 전두개 방사선조사는 안전하게 그리고 효과적으로 이용될 수 있을것이다.

• 대한수의학회지
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• 제37권2호
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• pp.409-416
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• 1997

Bovine theileriosis caused by Theileria sergenti is the tick-borne intraery- throcytic piroplasmosis, that occurs in most regions of Korea. It results in severe economic losses on a farm caused by anemia, milk production loss, abortion and death. This study was undertaken to confirm the effects of the growth hormone and the insulin-like growth factor-I which are associated in the growth of cattle infected by T sergenti. The blood of one hundred and twenty ten-month Holstein was collected and the prepared blood smear was stained with acridine orange to investigate their parasitemia. And the hematological profiles were observed. According to the value of the hematocrit, they were categorized into four groups : Group 1 was under 20 percent, groups 2 and 3 were from over 21 to under 30 percent and from over 31 to under 35 percent and group 4 was over 36 percent. As the value of the hematocrit decreased, parasitemia(%) in erythrocytes was observed to increase(Y=-1.064X + 30.537, r=0.660). The amounts of the growth hormone and the insulin-like growth factor-I in the serum were measured by the radioimmunoassay. The growth hormone in serum of the group 1, group 2, group 3 and group 4 were observed as $0.238{\pm}0.043nmol/l$, $0.21{\pm}0.024nmol/l$, $0.366{\pm}0.035nmol/l$ and $0.646{\pm}0.223nmol/l$, respectively. The quantitative of the insulin-like growth factor-I in the same groups were observed also as $209.686{\pm}18.94ng/ml$, $250.9{\pm}12.609ng/ml$, $279.3{\pm}8.883ng/ml$ and $365.9{\pm}22.45ng/ml$, respectively. It can be concluded that the growth hormone and the insulin-like growth factor-I were observed to decrease in severe anemia due to theileriosis.

• Journal of Periodontal and Implant Science
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• 제29권1호
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• pp.51-63
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• 1999

Exposure of the root surface due to gingival recession after periodontal surgery, elicit pain response when exposed to mechanical, heat, chemical or osmotic irritation. Especially patients treated with periodontal surgery, show high frequency. There have been reports that the 1 out of 7 patients complains of dentinal hypersensitivity. There have been many studies on the clinical effects of various materials on the treatment of dentinal hypersensitivity. The purposes of this study were to evaluate the effect of sodium chloride and potassium oxalate and to observe the relationship between the dentinal hypersensitivity and surface characteristics such as dentinal tubule size and number. This study included 20 teeth which were scheduled for extraction and had no pulpal disease. These teeth were divided into Root planing group, EDTA group, NaCl group and Oxalate group. Dentinal hypersensitivity is measured by tactile, pressured air and cold water using NRS (Numerical Rating Scales). Teeth were extracted under local anesthesia and each specimen was sectioned to a size about 3 X 5 mm and was examined under the scanning electron microscope (X2,000) The results were as follows, 1. The EDTA group exhibited significantly increased dentinal hypersensitivity comparing with the other groups. 2. The NaCl and Oxalate groups showed significantly reduced dentinal hypersensitivity comparing with the EDTA group. 3. As a method for dentinal hypersensitivity measurement, it was presumed thet tactile sensitivity test was not sensitive method but air blast test and cold water test were adequate method. 4. In a SEM study, the root planing group exhibited amorphous smear layer and showed no dentinal tubule orifice, but the EDTA group showed the large number of dentinal tubules. On the other hand, the NaCl and Oxalate groups did not show exposed dentinal tubules. The NaCl group showed more rough root surface than the EDTA group, and the Oxalate group showed many participates to be presumed as calcium oxalate particle. As the results from this study, root planing couldn't expose the dentinal tubule and NaCl and potassium oxalate occluded exposed dentinal tubule effectively. Dentinal hypersensitivity has close relationship with the exposure of dentinal tubules, especially with it's size and number.

• 한국임상약학회지
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• 제10권3호
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• pp.101-106
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• 2000

Menopausal women experience urogenitory and vasomotor symptoms with increased risk of osteoporosis and cardiovascular diseases, which can be reduced by hormone replacement therapy. However unopposed estrogen therapy has been associated with an increased risk of endometrial hypeiplasia or cancer. The objectives of this study were to compare effects of continuous vs. sequential hormone replacement therapy (HRT) on lipid profile, bone mineral density and menopausal symptoms of postmenopausal women and to assess how they perceive the menopause and HRT culturally. In this retrospective study, women in menopause longer than 6 months, normal in the mam-mogram and Papanicolaou smear, cholesterol level lower than 190 mg/dL or triglyceride level lower 4han 500 mg/dL were treated with Srogen (conjugated equine estrogen 0.625 mg tablet) and Provera (medroxyprogesterone acetate 2.5 mg tablet) for continuous treatment(CT) or Cycloprogynova (Estradiol valerate 2 mg and Norgestrel 0.5 mg complex tablet) for sequential treatment(ST). They were evaluated for lipid profile, bone mineral density, menopausal symptoms, side effects and their perception of menopause and HRT. As results, total sixty-seven patients out of ninety-four enrollees were included in final analysis (33 in continuous therapy, 34 in sequential therapy). There were significant decrease in total cholesterol ($15.04\pm3.17$, p=0.0001), LDL ($19.72\pm3.27$, p=0.0001), and increase in HDL ($5.89\pm1.63$, p=0.0001). Bone minora) density increased significantly with HRT ($0.02\pm0.11$, p=0.0001). But, there were no significant differences in change of lipid profile between continuous and sequential therapy: Total cholesterol, $13.12\pm4.7\;vs.\;16.91\pm4.3;\;LDL\;20.53\pm4.1\;vs.\;18.93\pm5.12:HDL\;7.15\pm2.3\;vs.\;4.67\pm2.2,\;p>0.05$. Incidences of flush reduced from $75\%\;(CT)\;to\;3.13\%\;and\;71.88\%\;(ST)\;to\;9.35\%$. The change of endometrium and breast were found 3 (CT) and 5 (ST) women, respectively. Most of women recognized that HRT is necessary $(70\%)$ for postmenopausal period but did not understand well the cardiovascular protective effect. In conclusion, hormone replacement therapy was effective in improving lipid profile, bone mineral density and menopausal symptoms in both continuous and sequential treatments with similar efficacy.

• 대한치과보존학회:학술대회논문집
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• 대한치과보존학회 2001년도 추계학술대회(제116회) 및 13회 Workshop 제3회 한ㆍ일 치과보존학회 공동학술대회 초록집
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• pp.577-577
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• 2001

The lastest concepts in bonding are "total etch", in which both enamel and dentin are etched with an acid to remove the smear layers, and "wet dentin" in which the dentin is not blown dry but left moist before application of the bonding primer. Ideally, the application of a bonding agent to tooth structure should be insensitive to minor contamination from oral fluids. Clinically contaminations such as saliva, gingival fluid, blood and handpiece lubricant are often encountered by dentists during preparation of a restoration. The aim of this study was to evaluate the effect of contamination by hem-ostatic agents on shear bond strength of compomer restorations. One hundred and ten extracted human maxillary and mandibular molar teeth were collected. The teeth were cleaned from soft tissue remnant and debris and stored in physiologic solution until they were used. Small flat area on dentin of the buccal surface were wet ground serially with 400, 800 and 1200 abrasive paper on automatic polishing machine. The teeth were randomly divided into 11 groups. Each group was conditioned as follows: Group 1 : Dentin surface was not etched and not contaminated by hemostatic agents. Group2 : Dentin surface was not etched but was contaminated by Astringedent (Ultradent product Inc., Utah, U.S.A.). Group3 : Dentin surface was not etched but was contaminated by Bosmin (Jeil Phann, Korea.). Group4 : Dentin surface was not etched but was contaminated by Epri-dent (Epr Industries, NJ, U.S.A.). Group5: Dentin surface was etched and not contaminated by hemostatic agents. Group 6 : Dentin surface was etched and contaminated by Astringedent. Group7 : Dentin surface was etched and contaminated by Bosmin. Group8 : Dentin surface was etched and contaminated by Epri-dent. Group9 : Dentin surface was contaminated by Astringedent. The contaminated surface was rinsed by water and dried by compressed air. Group10 : Dentin surface was contaminated by Bosmin. The contaminated surface was rinsed by water aud dried by compresfed air. Group 11 : Dentin surface was contaminated by Epri-dent. The contaminated surface was rinsed by water and dried by compresfed air. After surface conditioning, F2000 was applicated on the conditoned dentin surface. The teeth were thermocycled in distilled water at $5^{\circ}C\;and\;55^{\circ}C$ for 1000 cycles. The samples were placed on the binder with the bonded compomer-dentin interface parallel to the lmife-edge shearing rod of the Universal testing machine(Zwick 020, Germany) running at a cross head speed of 1.0mmimin. There were no significant differences in shear bond strength between groups 1 and group 3 and 4, but group 2 showed significant decrease in shear bond strength compared with group 1. There were no significant differences in shear bond strength between group 5 and group 7 and 8, but group 6 showed significant decrease in shear bond strength compared with group 5. There were no significant differences in shear bond strength between group 5 and group 9, 10 and 11.

• Restorative Dentistry and Endodontics
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• 제22권1호
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• pp.479-489
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• 1997

The purpose of this study was to evaluate the effect of the Nd : YAG laser on the tooth hypersensitivity by the observation of the morphological changes of the dentinal surface irradiated with Nd : YAG laser by use of SEM. In 40 mandibular and maxillary molars without any carious lesion or restoration, severe attrition and abrasion, Enamel was removed with fine grit diamond bur and exposed dentinal surfaces were polished with Soflex discs. In control group (10 teeth), exposed dentinal surfaces were acid-etched with 10 % Maleic acid for 15 seconds. In the experimental group 1 (10 teeth), acid-etched dentinal surfaces with 10% Maleic acid were prepared by Nd : YAG laser (6 watts power, 1 psi water, 18 psi air) for 2 minutes. In the experimental group 2 (10 teeth), exposed dentinal surfaces were irradiated with Nd: YAG laser (10 watts power, 3 psi water, 10 psi air) until the painted black stains on the dentinal surfaces were completely removed. In the experimental group 3 (10 teeth). dentinal surfaces were prepared with Nd : YAG laser (6 watts power, 1 psi water, 18 psi air) until the painted black stanins on them were completely removed and then the irradiated dentinal surfaces were acid-etched with 10 % Maleic acid for 15 seconds. The specimens were routinely processed and observed with scanning electron microscope. The results were as follows : 1. In the irradiated dentinal surfaces, the characteristics of the melting and recrystalization on the dentinal surfaces were observed. Compared with the results in the control group, we could observe that in the irradiated dentinal surfaces, the aperture of the dentinal tubules were reduced and there were more debris obstructing the dentinal tubules. 2. In the irradiated dentinal surfaces, crater structures were commonly present and in the crater bottoms, there were a lot of bead like melted dentin structures, which had the ruptured opening in the center of them. 3. The melted dentins and cracks in the smear layer were less frequently observed in the irradiated dentinal surfaces using copious cooling water than in the irradiated dentinal surfaces using scare cooling water.