태연혈(太淵穴)의 유침 시간에 따른 체온 변화 -적외선체열촬영(赤外線體熱撮影)을 중심으로-

이봉효 ( Bong Hyo Lee ),이경민 ( Kyung Min Lee ),박지하 ( Ji Ha Park ),김민서 ( Min Seo Kim ),김산들 ( San Deul Kim ),박병규 ( Byeong Gyu Park ),양현동 ( Hyun Dong Yang ),예성호 ( Sung Ho Yea ),이호정 ( Ho Jung Lee ),최재원 ( Jae 경락경혈학회 2012 Korean Journal of Acupuncture Vol.29 No.2

Objectives: This study was performed to find the desirable remaining time of needle in the acupuncture treatment. Methods: The 21 volunteers were given acupuncture at LU9 vertically and needles were remained for 2 min, 10 min, 15 min, 30 min, respectively. The thermographic change induced by acupuncture was measured with Digital Infrared Thermographic Image at the following acupoints: LU11, LU10, LU9, LU8, LU5, LU1, and PC7. The statistical significance of thermographi change was evaluated using paired t-test and post hoc Wilcoxon test. Results: The most significant changes after acupuncture were produced when needles were remained for 10 min or 15 min. LU11, LU5, LU1, and PC7 were the point at which all of the remaining time produced significant change commonly. At LU11, the biggest change was produced when needle was remained for 15 min, while at LU5, LU1, and PC7, the biggest change was produced when needle was remained for 30 min, and the smallest change was produced when needle was remained for 10 min at all of acupoints of LU11, LU5, LU1, and PC7. The unbalance between left side and right was decreased the most largely in 15 min group. Conclusions: The results of this study suggest that the desirable remaining time of acupuncture needle might be 15 min.

측방가압충전시 Nickel-Titanium spreader의 사용유무가 근관충전효과에 미치는 영향

민경산,홍찬의,조용범 대한치과보존학회 2000 Restorative Dentistry & Endodontics Vol.25 No.3

Lateral condensation with gutta-percha and sealer has been shown to provide an excellent apical seal: however, the lateral condensation technique has demonstrated less favorable apical leakage results in curved canals when compared with straight canals. Placement of endodontic spreaders to within 1 to 2mm of the root canal working length has been advocated for Optimum gutta-percha obduration. Due to their stiffness, stainless-steel(SS) spreaders will often fail to achieve this position in curved canals. Newly marketed nickel-titanium (NT) spreaders may offer an advantage in this regard due to the increased flexibility of these instruments. The purpose of this study was to evaluate the effect of NT finger spreader on the sealing ability in lateral condensation technique, compared with conventional SS finger spreader. Twenty four standardized resin models simulating curved canals(30 degree) were groups and instrumented to a #30 master apical ale size with Ni-Ti Profile .04 taper series using step down technique. Each groups was obdurated with pique using SS finger spreader, NT finger spreader. And then, each model was sectioned horizontally with microtome at 1, 2, 3, 4, smm levels from the apex. At each of 5 levels, ratio of the area of gutta-percha was obtained by calculating the area of Ntta-percha to the total area of the canal. The data collected were then analyzed statistically using a t test for indepent samples. The results as follows: 1.The total mean ratio of area of gutta-percha was 89.20±7.00(%) for SS sprender group. 99.20±5.17(%) for NT spreader group.There was statistically significant difference between each group(p〈0.05). 2.At 3mm level, the mean ratio of area of Ntta-percha was 88.32±5.41(%) for SS spreader group, 95.25±2.60(%) for NT spreader group. There was statistically significant difference between each group(p〈0.05) . At 1,2,4mm levels, NT spreader group showed greater mean ratio of area of gutta-percha than SS spreader group, too. But there was no statistically significant difference. 3.At 5mm level, the mean ratio of area of Ntta-percha was 91.83±3.42(%) for SS spreader group. 87.91±3.68(%) for NT spreader group. There was statistically significant difference between each group(p〈0.05). This study concluded that the NT spreader demonstrated somewhat favorable apical sealing efffct than 55 spreader in prepared curved canals. The clinical use of NT spreaders may enhance our ability to create better apical seals in curved canals, but further studies in this area will help clarify some of fhe remainingareas with which practitioners are concerned, such as compaction forces exerted by NT spreaders.

24시간 혈압 감시를 통한 만성 뇌졸중 환자에서의 야간 혈압 강하 현상의 연구

정산,이병철,유경호,정승철,김성민,권기한,황성희 대한신경과학회 1996 대한신경과학회지 Vol.14 No.4

한국인의 상악 제1대구치 근심 협측 치근의 근관형태에 관한 연구

민경산,김용관 關東大學校 醫科大學 醫科學硏究所 2003 關東醫大學術誌 Vol.7 No.1

The purpose of this study was to determine the percentage of anatomical canal configurations of the mesiobuccal root of the maxillary first molar in Korean patients. One hundred and fifty extracted maxillary first molar was used in this study. The distobuccal and palatal roots were amputated for radiographic convenience. Preoperative radiographs were taken of the remaining crown and mesiobuccal root from mesiodistal and buccopalatal directions for each tooth. Endodontic access cavities were prepared and size 15 K file were placed to the apexes. postoperative radiographs with files in place were taken from the two directions, as before. Of the 150 teeth,58 (38.7%) were TypeⅠ,47 (31.3%) were Type Ⅱ,42 (28.7%) were Type Ⅲ, 2 (1.3%) were Type Ⅳ. It is concluded that two canals in mesiobuccal roots of maxillary first molars of Korean is a common occurrence and the proportion of cases was high and similar to that described from studies of other ethnic populations.

재생 폴리에텔렌의 기계적 성질 : 충격 보강재 효과에 대하여

계형산,강경민,박종훈,정융권,이상환 목원대학교 자연과학연구소 2002 自然科學 硏究論文集 Vol.11 No.2

본 연구는 재활용이 가능한 폴리에틸렌 필름 등에 비산회(Fly Ash) 등의 충진재를 사용하여, 신재와 물성을 비교하여 재생 PE의 재활용 가능성 및 사용 가능한 충진재의 종류를 알아보는데 그 목적이 있다. 또한 본 연구에서는 치합형 동방향 회전 이축 압출기(Fully Intermeshing Co-rotating Twin Screw Extruder)를 이용해서 재생 Polyethylene에 비산회 및 다양한 충진재(filler)를 첨가하여 ASTM에 의거하여 충격시편을 만들었고, 각 충진재의 무게비에 따른 충진재 충격 시험을 하였으며 Capillary Rheometer를 이용하여 유변학적인 성질을 분석해 보았다.

광조사 시간에 따른 복합레진과 Ormocer의 중합수축에 관한 연구

정연정,민경산,이해형,조경모,조용범 大韓齒科保存學會 2003 Restorative Dentistry & Endodontics Vol.28 No.4

Ormocer has organic-inorganic compound polymers. One of advantages of ormocer is reduced polymerization shrinkage. The purpose of this study was to compare the amount of contraction shrinkage of composite resins and ormocers. Additionally, the time of each material when there is no further change of contraction shrinkage was analysed. Four brands of composite resins (P-60, Surefil, Z-250 and Denfil) and two brands of ormocers (Definite and Admira) were used. 20 seconds, 40 seconds and 60 seconds of curing times were given. Contraction shrinkage of them were measured using a linometer for 80 seconds. The effect of material and curing time to contraction shrinkage at the time of 80 seconds was analysed by two-way ANOVA. The effect of time to contraction shrinkage was analysed by one-way ANOVA, and the time when there was no further change of the contraction shrinkage was analysed. The results are as follows : 1. P-60, Dfinite, Z-250 and Denfil had no further change of contraction shrinkage from the time of 20 seconds, and Surefil and Admira had no further change of contraction shrinkage from the time of 10 seconds. 2. Statistical analysis revealed volumetric shrinkage varied among material (p<0.05). No significant difference of contraction shrinkage among different curing times was found, and there was no effect of interaction between materials and curing times to contraction shrinkage. 3. Dfinite and Admira showed the statistically same contraction shrinkage with those of Z-250 and P-60, which is higher than that of Surefil and lower than that of Denfil (p<0.05).

다양한 복합레진 시스템의 변연 누출도

김인수,민경산,신동훈 大韓齒科保存學會 2003 Restorative Dentistry & Endodontics Vol.28 No.2

The object of this study was to compare the microleakage between various composite resin systems of multistep, one-bottle, and self-etching systems using electrical conductivity. After making class V cavities (4×3×1.5 mm around CEH), they were bulk filled with three kinds of resins of A3. Teeth were storaged in a saline solution for one day, after then, they were finished and polished using Sof-Lex system. Another stress of thermocycling was made for 500 times from 5° to 55 ℃ with each dwelling time of 10 seconds. Electrical conductivity (microamphere, ㎂) was checked four times: before and after cavity preparation, after filling, after thermocycling. One-way ANOVA and 95% Scheffe Post Hoc test was used for checking any statistical difference among groups. Another 95% Paired Samples T-test was also used for estimating any significant difference within group after cavity filling or thermocycling. The results were as follows: 1. Every specimen showed various range of microleakage after filling. There was, however, no difference between composite resin systems. 2. All composite resin systems showed marked increase in microleakage with a thermocycling (p<0.05). there was, however, no difference between composite resin systems. 3. Although there was no significant difference between groups (p=0.078), one-bottle and self-etching systems seemed to be unstable than multistep system. Within the limits of this study, it was concluded that much more consideration should be needed when using thermally unstable one-bottle and self-etching systems that have multi-advantages from simplified step. More studies will be needed to solve these kinds of problems.

가변 광도에 따른 복합레진의 기계적 물성 및 변연누출도 변화

한승렬,민경산,신동훈 大韓齒科保存學會 2003 Restorative Dentistry & Endodontics Vol.28 No.2

Mechanical properties and microleakage of two composites [conventional hybrid type DenFil (VERICOM Co., Anyang, Korea) / micro matrix hybrid type Esthet X (Dentsply Caulk, Milford, DE, U.S.A.)] were evaluated to assess whether variable light intensity curing is better than conventional curing technique. Curing was done for 40 seconds in two ways of 2 step soft-start technique and 5 step ramping technique. Three kinds of light intensities of 50, 100, 200 mW/cm^2 were initially used for 10, 20, 30 seconds each and the maximum intensity of 600 mW/cm^2 was used for the rest of curing time in a soft-start curing technique. In a ramping technique, curing was done with the same initial intensities and the light intensity was increased 5 times with the same rate to the maximum intensity of 600mW/cm^2. After determining conditions that showed no different mechanical properties with conventional technique, Esthet X composite was filled in a class V cavity, which dimension was 4×3×1.5 mm and cured under those conditions. Microleakage was evaluated in two ways of dye penetration and maximum gap estimation through SEM observation. ANOVA and Spearman's rho test were used to confirm any statistical significance among groups. The results were as follows: 1. Several curing conditions of variable light intensities resulted in the similar mechanical properties with a conventional continuous curing technique, except conditions that start curing with an initial light intensity of 50 mW/cm^2, 2. Conventional and ramping techniques were better than soft-start technique in mechanical properties of microhardness and compressive strength. 3. Soft-start group that started curing with an initial light intensity of 100 mW/cm^2 for 10 seconds showed the least dye penetration. Soft-start group that started curing with an initial light intensity of 200 mW/cm^2 for 10 seconds showed the smallest marginal gap, if there was no difference among groups. 4. Soft-start technique resulted in better dye-proof margin than conventional technique(p=0.014) and ramping technique(p=0.002). 5. There was a very low relationship(p=0.157) between the methods of dye penetration and marginal gap determination through SEM evaluation. From the results of this study, it was revealed that ramping technique would be better than conventional technique in mechanical properties, however, soft-start technique might be better than conventional one in microleakage. It was concluded that much endeavor should be made to find out the curing conditions, which have advantages of both aspects or to solve these kinds of problems through a novel idea of polymerization.

자가 산부식 프라이머 시스템 사용시 인산에 의한 부가적인 산부식이 미세누출에 미치는 영향

윤정진,민경산,홍찬의 大韓齒科保存學會 2003 Restorative Dentistry & Endodontics Vol.28 No.5

The purpose of this study is to evaluate the effect of additional enamel etching with phosphoric acid on the microleakage of the adhesion of self-etching primer system. Class V cavity(4mm × 3mm × 1.5mm) preparations with all margins in enamel were prepared on buccal surface of 42 extracted human upper central incisor teeth. Prepared teeth were randomly divided into 3 groups. Group 1:no additional pretreatment with 37% phosphoric acid (NE). Group 2:additional pretreatment with 37% phosphoric acid for 10 seconds (E10s). Group 3:additional pretreatment with 37% phosphoric acid for 20 seconds (E20s). The adhesives(Clearfil SE Bond, Kuraray, Osaka, Japan) and composite resins(Clearfil AP X, Osaka, Kuraray, Japan) were applied following the manufacturer's instructions. All the specimens were finished with the polishing disc(3M dental product, St Paul, MN, USA), thermocycled for 500 cycles between 5℃ and 55℃ and resected apical 3mm root. 0.028 stainless steel wire was inserted apically into the pulp chamber of each tooth and sealed into position with sticky wax. Surrounding tooth surface was covered with a nail varnish 2 times except areas 1mm far from all the margins. After drying for one day, soaked the samples in the distilled water. Microleakage was assessed by electrochemical method(System 6514, Electrometer, Keithley, USA) in the distilled water. In this study, the microleakage was the lowest in group 1 (NE) and the highest in group 3(E20s)(NE<E1Os<E20s). But no statistically significant differences were found(p =0.5) On the basis of findings from this experiment, it can be concluded that additional enamel etching has nc influence on the microleakage of the adhesion of self etching primer system.

감염 조절용 차단막의 두께가 광중합기의 중합광에 미치는 영향

장훈상,이석련,홍성옥,류현욱,송창규,민경산 大韓齒科保存學會 2010 Restorative Dentistry & Endodontics Vol.35 No.5

연구목적: 본 연구는 감염 조절용 차단막을 여러 겹으로 사용했을 때 광중합기의 광강도와 파장, light diffusion 등에 미치는 영향에 대해 조사하였다. 연구 재료 및 방법: 감염 조절용 차단막은 투명 랩 (크린랩)을 사용하였고 광중합기는 할로겐 광중합기 (Optilux 360)와 LED 광중합기 (Elipar FreeLight 2)를 사용하였다. 차단막을 1겹, 2겹, 4겹, 8겹으로 광중합기의 광섬유말단을 감싸고 휴대용 광강도 측정기 (Cure Rite)로 광중합기의 광강도를 측정하였다. 광중합기를 주문제작한 optical breadboard에 고정시킨 후 휴대용 spectroradiometer (CS-1000)를 이용하여 광중합기의 파장을 측정하였고, DSLR (Nikon D70s)을 이용하여 광중합기의 light diffusion을 사진 촬영하였다. 결과: 광강도 측정 결과는 차단막의 두께가 증가할수록 광강도가 유의하게 감소하였으나 할로겐 광중합기에서 1겹과 2겹 사이에는 유의차가 없었으며, 4겹 이상의 차단막을 투과할 때 광강도가 더 많이 감소하였다. 여러 겹의 차단막을 투과한 광중합기의 전체적인 파장 형태와 peak wavelength의 변화는 관찰되지 않았다. Light diffusion 사진 촬영 시, LED 광중합기에서는 차단막의 두께가 미치는 영향이 없었으나 할로겐 광중합기에서는 차단막을 4겹 사용했을 때부터 중합광이 조사되는 각도가 감소하기 시작하여 8겹 사용했을 때 통계적으로 유의하게 감소하는 것을 볼 수 있었다 (p < 0.05). 결론: 광중합형 복합레진을 광중합할 경우 감염 조절용 차단막이 찢어지는 경우를 대비하여 1겹으로 사용하기 보다는 2겹으로 사용하는 것이 환자간의 교차감염을 예방하는데 유리할 것으로 사료된다. Objectives: This study investigated the effect of infection control barrier thickness on power density, wavelength, and light diffusion of light curing units. Materials and Methods: Infection control barrier (Cleanwrap) in one-fold, two-fold, four-fold, and eightfold, and a halogen light curing unit (Optilux 360) and a light emitting diode (LED) light curing unit (Elipar FreeLight 2) were used in this study. Power density of light curing units with infection control barriers covering the fiberoptic bundle was measured with a hand held dental radiometer (Cure Rite). Wavelength of light curing units fixed on a custom made optical breadboard was measured with a portable spectroradiometer (CS-1000). Light diffusion of light curing units was photographed with DSLR (Nikon D70s) as above. Results: Power density decreased significantly as the layer thickness of the infection control barrier increased, except the one-fold and two-fold in halogen light curing unit. Especially, when the barrier was four-fold and more in the halogen light curing unit, the decrease of power density was more prominent. The wavelength of light curing units was not affected by the barriers and almost no change was detected in the peak wavelength. Light diffusion of LED light curing unit was not affected by barriers, however, halogen light curing unit showed decrease in light diffusion angle when the barrier was four-fold and statistically different decrease when the barrier was eight-fold (p < 0.05). Conclusions: It could be assumed that the infection control barriers should be used as two-fold rather than one-fold to prevent tearing of the barriers and subsequent cross contamination between the patients.