부산지역(釜山地域) 치과기공소운영자(齒科技工所運營子)의 전문대학(專門大學) 치과기공과출신(齒科技工科出身) 치과기공사(齒科技工士)에 관(關)한 만족도(滿足度) 조사(調査)

이명곤,Lee, Myung-Kon 대한치과기공학회 1988 대한치과기공학회지 Vol.10 No.1

The great sudden change of circle of dental laboratory technology brought many discord between the new growing environmental group and the old group. In order to know the satisfactory degree of Dental Laboratory Heads about all and woman dental technicians who graduated from junior college, this study was conducted for 41 dental laboratory heads in Pusan area during Aug. to Sep. 1986 by means of a questionaire. The results are obtained as follows : 1. By born place, the dental laboratory heads’ satisfactory degree mean of items about all dental technician who graduated from junior college were Pusan group 3.55, Kyungnam group 2.94. The difference among the groups was significant enough(P<0.05). The satisfactory degree about woman dental technician graduated from junior college were Pusan group 3.45, Kyungnam group 2.72. 2. By age, The degree of satisfaction of items about all graduate dental technician were 30$\sim$34 age group 3.13, 40$\sim$44 age group 2.71. The degree of satisfaction about woman graduate dental technician were 30$\sim$34 age group 3.13, 40$\sim$44 age group 2.71. The degree of satisfaction about woman graduate dental technician were as follow : 35$\sim$39 age group 3.50, 45$\sim$49 age group 3.16, 30$\sim$34 age group 2.86, 40$\sim$44 age group 2.43. 3. By job career, the highest degree item out of satisfaction about all graduate dental technician was 6$\sim$10 years group 3.58, the other items were 1$\sim$15 years group 2.90, 16$\sim$20 years group 2.71. The satisfactory degree item about woman graduate dental technician was 6$\sim$10 years group 3.43, 16$\sim$20 years group 3.15, 11$\sim$15 years group 2.82 respectively. 4. By managing term of respondents’ dental laboratory, the satisfactory degree of items about all graduate dental technician were below 2 years group 3.25, 3$\sim$6 years group 3.14, 7$\sim$10 years group 2.93 in order. The satisfactory degree items about woman graduate dental technician were 11$\sim$14 years group 3.25, 3$\sim$6 years group 3.14 7$\sim$10 years group 2.80 in order. 5. By acquired qualification of licence test, the satisfactory degree of dental laboratory heads about all graduate dental technician were job career group 3.07, graduated from Dept. of Dental Technology group 3.00. The satisfactory degree about woman graduate dental technician were job career group 3.03 and graduated from Dept. of Dental Technology group 2.57. 6. By dental technician numbers of respondents’ dental laboratory. the satisfactory degree of items was as follow: 10$\sim$13 persons group is 2.86, 6$\sim$9 persons group 3.25, below 5 persons group 3.11. There was significant enough.(P<0.01). The satisfactory degree items about woman graduate dental technician were below 5 persons group is 3.00, 10$\sim$13 persons group 2.79, 6$\sim$9 persons group 2.67. 7. by the outlook of occupation, the satisfactory degree of dental laboratory heads about all dental technicians who graduated from junior college were neither good norbad group 3.20 bad group 2.59, good group 3.13. The difference among the groups was significant enough(P<0.01). The satisfactory degree about woman dental technicains graduated from junior college were good group 3.25, neither good nor bad group 2.80, bad group 2.75. The difference among the groups was significant enough.(P<0.01) 8. By occupational satisfaction, The satisfactory degree of items about all graduate dental technician were neither satisfied nor dissatisfied group 3.08, satisfied group 3.17, dissatisfied group 2.89. The satisfactional degree of items about woman graduate dental technician were satisfied group and neither satisfied mor dissatisfied group each 3.00 9. By the outlook of employment, the satisfactory degree o

열중합(熱重合) 의치상(義齒床) Resin과 합성수지인공치(合成樹脂人工齒)의 결합강도(結合强度)에 관(關)한 연구(硏究)

이명곤,Lee, Myung-Kon 대한치과기공학회 1986 대한치과기공학회지 Vol.8 No.1

One of the primary advantage of acrylic resin teeth is their ability to bond chemically to the denture base resins. But, occasionally, failure have been observed in which acrylic resin teeth break lose from the denture, indicating that chemical bonding does not always occur. The most probable explanation for this type of failure was the presence of a trace of wax remaining as a residue on the surfaces of the teeth after the boiling-out procedure which adgered to the tooth surface and prevented bonding. The purpose of this stdy was preparing the specimens of denture base resin with acrylic resin teeth that four treatment method to ridge lap portion of the tooth and investigated bond between the teeth and denture base resin with tensile strength. Compared results of tensile strength on test specimens were as follows: 1. The mean of strength among the four test groups showed the difference was significant enough(P 0.01). The order of its strength mean was methylene chloride treatment group, detergent solution treatment group, kerosene-ether treatment grgoup, boiling water only group. 2. In compared results between the wax eliminating method groups, there were significant difference between the boiling water only group and other groups(P 0.01), no significant difference were found in the wax eliminating method groups except boiling water only group(P 0.05).

부산지역(釜山地域) 개업치과(開業齒科)의 치과보철물(齒科補綴物)에 관(關)한 만족도(滿足度) 조사(調査)(I) - 일부정식 치과 보철물에 관하여 -

이명곤,Lee, Myung-Kon 대한치과기공학회 1988 대한치과기공학회지 Vol.10 No.1

Fixed prosthetic appliance is the restorations of damaged teeth with cast metal or porcelain, and of replacing missing teeth with fixed, or cemented prosthesis. Successfully treating a patient by means of fixed prosthodontics requires the thoughtful combination of dentist and dental laboratory technician. In order to know the satisfaction of dentisits about fixed prosthetic appliances-porcelain, precious and non precious metal-, this study was conducted for 69 practicing dentisis in Pusan during Fed. to Mar. 1988 using a questionnaire method and was analyzed by the use of percentage, $X^2$-test The results are obtained as follow: 1. General characteristics of the respondents, The rate of age distribution of practcing dentists responded was as follow : 31$\sim$35 age group is 29.0%, 51$\sim$55age group 18.8%, 41$\sim$45 age group and 46$\sim$50 group each 11.6%, 36$\sim$40 age group and 56$\sim$60 age group 8.7%, over 60 age group 7.3%, below 30 age group 4.3% respectively. The tate of term of practice experience distribution of dentists responded was as follow : 6$\sim$10 year group 26.1%, 25$\sim$25year group 18.8%, 11$\sim$15 years group and 16~20 years group each 13.0%, below 5 years group and over 30 years group each 10.2%, 26$\sim$30 years group 8.7% in order. The rate of respondents’ degree was follow : bachelor group 81.2%, doctor group 13.0%, master group 5.8% in order. The rate of respondents’completed medical specialist course was as follow : non-complete group 75.4%, complete group 24.6%. The rate of having own laboratory in respondents’clinic was as follow : no having own laboratory group 58.0%, having own labiratory group 42.0% The rate of being lab. technician in respondent;s clinic was as follow: non-being lab. technician group 91.3%, being lab. technician group 8.7%. The rate of transactional commercial dental lab. numbers was as follow : I dental lab. group 40.6%, 2 dental lab. group 30.4%, 3 dental lab. group 20.3%, production at own lab. group 8.7% 2. Cognitions about the respondent's job, About cognition of patient numvers, there were neither many nor few group 62.3%, few group 17.4%, many group 15.9%, too many group 4.4% in order.(P<.01) As compared with the ratio of dentists to patient prothetic treatment, there were moderate level group 46.4%, high level group 33.6%, low level group 18.8% in order.(P<.01) By job satisfaction of respondents, the highest percentage group was satisfied group 44.9%, neither astisfied nor disstified group 33.3%, dissatisfied group 14.5%, much satisfied group 7.3%(P<.01). As compared with the level of prosthetics price, the were moderate level group 71.0%, low level group 23.2%, high level group 5.8%(P<.01) 3. Satisfaction and assessment of dissatisfied factor of the fixed prosthetic appliance, As compared with the satisfaction of al prosthetic appliance, there were neither satisfied nor dissatisfied group 59.4%, satisfied group 20.3% dissatisfied group 18.8%, much satisfied group 1.5% in order.(P<.01). About precious and non precious metal crown and bridge, there were neither satisfied nor dissatisfied group 60.9%, satisfied group 24.6%, dissatisfied group 11.6%, much satisfied group 2.9% in order.(P<.01) The reat of respondent;s satisfaction about porcelain crown and bridge was as follow : neither satisfied nor dissatisfied group 43.5%, dissatisfied group 33.3%, satisfied group 21.7%, much satisfied group 1.5%(P<.01). The rate of respondent's dissatisfied factor item of precious and non precious metal crown and bridge was as follow : inadequate margin fit item 39.1% respondent, inadequate occlusion item 24.6%, inadequate adaptation item 23.2%, poor anat omic form item 15.9%, inadequate contact item 31.9%, improper polishing item 4.4%, the rest item 11.6% respectively. The rate of respondent's dissatisfied factor item of porcelain crown and bridge was

경사하중에 따른 시멘트 유지형 임플란트 지지골의 유한요소법 응력 분포

이명곤(Myung-Kon Lee) 한국콘텐츠학회 2014 한국콘텐츠학회논문지 Vol.14 No.9

The dental osseointegration implant should be enough to endure occlusion load and it"s required to have efficient design and use of implant to disperse the stress into bones properly. Solidworks as a finite element analysis program for modeling and analysis of stress distribution was used for the research. The simple crown model was designed on applying conjoined condition with tightening torque of 20 N㎝ of a abutment screw between a cement retained implant abutment and a fixture. A 45° oblique loading from lingual to buccal side on buccal cusps of crown and performed finite element analysis by 100 N of external load. The results by a analysis for stress distribution of supporting bones of fixture were as below. The von Mises stress was concentrated on the upper side of supporting compact bone regardless of the diameters and lengths of fixture, and the efficiency result of stress reduction was increase of fixture"s diameter than it"s length. Therefore, it"s effective to use wider fixture as possible to the conditions of supporting jaw bone. 본 연구는 치과 임상에서 사용하고 있는 시멘트 유지형 치과용 임플란트의 지지골 응력 분포 안정성을 확인하고자 시행하였다. 모델링과 유한요소 응력 분석은 유한요소 해석 프로그램인 Solidworks를 사용하였고, 시멘트 유지형 임플란트 시스템인 지대주와 고정체를 연결하는 지대주 나사를 20 N㎝ 나사조임력에 의한 결합조건을 적용시킨 단관 모델을 제작하고, 설측에서 협측으로의 45° 경사로 100 N 크기 외부하중을 가하여 지지골 응력 분포 해석을 실시하였다. 경사하중에 따른 임플란트 고정체의 지지골 응력 크기와 분포를 파악하기 위한 유한요소법 분석을 통해 다음 결과를 얻었다. 고정체 직경, 길이의 조건에 관계없이 임플란트 고정체 상부와 골 접촉부인 치밀골에 응력이 집중되는 양상으로 나타났고, 고정체 길이 증가로 인한 응력 감소 폭보다 직경 증가로 인한 감소폭이 큰 것으로 나타났다 따라서 본 연구 결과는 지지골 형태 조건에 대하여 가능한 큰 직경의 고정체 사용이 효과적이라고 판단된다.

치과 교정용 듀플렉스 스테인리스 스틸 와이어의 기계적 강도 및 세포독성 평가

이명곤(Myung-Kon Lee),김치영(Chi-Young Kim) 한국콘텐츠학회 2010 한국콘텐츠학회논문지 Vol.10 No.9

치과 교정치료를 위하여 스테인리스 선재가 널리 사용되고 있다. 그러나 내식성이 우수한 스테인리스강 선재가 복합적인 구강환경에서 부식되어 구강조직에 과민반응 또는 이상반응이 발생되고 있다. 이러한 문제를 보완하기 위하여 본 연구에서는 초내식성의 듀플렉스 스테인리스 선재를 교정용 선재로 제시하고자 한다. DSS선재의 교정용 선재로 제시하기 위하여 기계적 강도와 생물학적 안정성을 평가하였다. 기계적 강도는 상용 교정용 SS선재와 6종의 열처리(실온(28℃), 500℃, 600℃, 700℃, 800℃, 900℃)를 실시한 DSS선재를 이용하여 인장강도시험을 실시하였다. 그리고 최적의 강도를 가지는 열처리 조건에서 제작된 DSS선재를 이용하여 굽힘 모멘트 시험을 실시하여 최대 응력과 탄성계수를 산출하였다. 그리고 생물학적 안정성 평가를 위하여 세포성장률 시험을 실시하였다. 선재를 이용하여 금속용출배지를 만들어 세포를 배양 후 세포성장률을 관찰하였다. 기계적 강도 평가 결과 SS선재(8.17×10⁴N/㎟)와 DSS500(8.05×10⁴N/㎟)선재가 유사한 기계적 강도를 가졌다(p=0.05). 생물학적 안전성 평가 결과 세포독성이 없는 것으로 나타났다(p=0.05). 따라서 본 연구에 제시한 초내식성의 듀플렉스 스테인리스 선재가 교정용 선재로 사용이 가능한 것으로 판단된다. The stainless steel wire is extensively used for the orthodontic treatment. But, the stainless steel wire that has commonly superior corrosion resistance has caused hypersensitive reaction or allergy as side effects because of corrosion in the oral environment. For improving the problem of corrosion, we was evaluated the suitability of the duplex stainless steel(DSS) as orthodontic wire through this study. The DSS wire was evaluated the mechanical strength and bio-stability for suitability and bio-compatibility as orthodontic wire. In this work, the DSS and stainless steel(SS) as common use of medical grade were prepared for the tensile strength test. The DSS wire were treated by heat. and Temperature conditions of the heat treatment were 28℃, 500℃, 600℃, 700℃, 800℃, 900℃, respectively. And the DSS wires that treated by heat on the optimum temperature condition were conducted the bending moment test and calculated the S-Max value and the modulus of elasticity. For evaluating the bio stability, each materials were conducted in vitro test for measuring the cell survival rate. The most interesting results was that the tensile strength test of SS wire(8.17×10⁴N/㎟) and DSS wire(8.05×10⁴N/㎟) that treated at 500℃ by heat were similar in mechanical strength. In the bio-stability study, the DSS has no cytotoxicity (p=0.05) Thus, we could make a conclusion that the duplex stainless steel wire has vastly superior corrosion resistance was suitable as orthodontic wire.

원발성 비후형 심근증에서 심근비후 형태에 따른 임상상의 차이

이명곤(Myung Kon Lee),박종수(Jong Su Park),안영근(Young Keun An),박주형(Ju Hyung Park),정명호(Myung Ho Jeong),조정관(Jeong Gwan Cho),박종춘(Jong Chun Park),강정채(Jung Chaee Kang),박옥규(Ock Kyu Park) 대한내과학회 1993 대한내과학회지 Vol.45 No.4

N/A Background; The idipathic hypertrophic cardiomyopathy(HCM) is characterized by inappropriate myocardial hypertrophy of unknown cause. It may presents a variety of clinical and morphologic features according to the site and extent of the hypertrophy. The widespread application of echocardiography has made it possible to diagnose HCM earlier and easier, even in asymptomatic patients. However, clinical reports on the relationship between the distribution of left ventricular hypertrophy (LVH) and the clinical features are few in Korea. Therefore, the present clinical stu4y was performed to characterize more completely the distribution of LVH and to determine whether different patterns of hypertrophy are of particular clinical significance. Methods: The clinical, electrocardiographic and echocardiographic features were reviewed in 32 patients with idipathic HCM of Chonnam National University Hospital from July 1983 to August 1992. Results: 1) There were 23 males and 9 females. The mean age was 45.4±16.5 ranging from 15 to 74 years. There were no significant difference in age distribution according to the patterns of LUH. 2) Based on M-mode and 2-dimensional echocardiographic findings. The 32 patients were divided into 2 groups; 16 patients in the obstructive HCM group and the other 16 patients in the non-obstructive HCM group. Among the 16 patients with non-obstructive HCM, there were 6 patients with asymmetric septal hypertrophy(septal HCM), 7 patients with apical hypertrophy (apical HCM), 3 patients with symmetric (concentric) hypertrophy (symmetric or concentric HCM). 3) The cardinal clinical symptoms were dyspnea (71.9%), chest pain (59.5%), palpitation(37.5%) and syncope (12.5%). There were no significant difference in the frequency of symptoms according to the patterns of LCH. 4) On chest X-ray examination, the enlargement of cardiac silhoutte (C/T ratiok≥0.55) was observed in 32% of the cases. There wedre 4 patients with C/T ratio ≥0.6, and all had obstructive HCM. 5) In conventional 12 leads electrocardiograms, abnormal electrocardiographic findings were obtained in 94% of the cases. Among them repolarization abnormalities and left ventricular hypertrophy were most common, occuring in 80.6% and 64.5%, respectively. This was followed by abnormal Q waves (37.5%), atrial fibrillation (29.0%) and giant T wave inversion (29.0%). Giant T wave inversion was significantly more common in patients with apical HCM than in any other patients. 6) On the M-mode echocardiograms, the ratio of left ventricular septal thickness to left ventricular posterior wall thickness (IVS/LVPW) was 1.58±0.36 in obstructive HCM, 1.55±0.08 in septal HCM, 1.05±0.14 in apical HCM, and 1.13±0.08 in symmetric HCM. 7) On the 2-dimensional echocardiograms, the ventricular septum and anterolateral free wall were significantly thicker compared to left ventricular posterior wall in patients with obstructive and septal HCM (p<0.001, p<0.01 respectively). The apical wall was significantly thicker compared to the other regions in patients with apical HCM. 8) Mital regurgitation was detected by Doppler echocardiography in 13 (40.6%) of the total 32 cases of HCM and especially in 11 (68.8%) of the 16 cases with obstructive HCM. 9) Continuous wave Doppler echocardiography of left ventricular outflow tract was performed in 10 patients with obstructive HCM and revealed a mean peak pressure gradient of 50.1±39.9mmHg (13~130mmHg) between the left ventricular (LV) mid cavity and the LV outflow tract. Conclusion: Clinical features are very similar in every pattterns of LVH. But the above results suggested that depending on the extent and distribution of LVH, the functional and morphologic features of HCM may differ considerably. It is still questionable whether identifiable patterns of hypertrophy are of clinical significance.

일부(一部) 대도시(大都市) 지역(地域) 치과기공사(齒科機工士)의 직업(職業) 및 직업장(職業場) 만족도(滿足度)에 관한 조사연구(調査硏究)

이태정,이명곤,Lee, Tea-Jung,Lee, Myung-Kon 대한치과기공학회 1985 대한치과기공학회지 Vol.7 No.1

This study has been to survey the present situation of satisfaction to the occupation and dental laboratory by means of selscting 200 dental technicians who are woked in Pusan, Deagu, Kwangju, Deajun. Questionaires were distributed to them and the summerized results were as follows; 1. In general, the dental technician's satisfaction of the occpation was revealed as moderate(Mn, 2.83), the dental technician's satisfaction of the laboratory was revealas moderate(Mn, 2.80). The highest degree item out of the satisfaction of occpation was the outlook(Mn, 3.23), and the lowest degree item was the advancement and the rise to a high position(Mn, 2.22). The highest degree item out of the satisfaction of laboratory was dental material(Mn, 3.07), and the lowest degree item was the equipment of dust collection(Mn, 2.49) 2. By age, the highest degree item out of the satisfaction of occpation was 30 to 43 group(Mn, 3.28), 50 and over group was the lowest degree item(Mn, 2.89). The highest degree item out of the satisfaction of laboratory was 40 to 50 group(Mn, 3.10), the lowest degree item was 35 to 39 group(Mn, 2.88). 3. By school career, the satisfaction of occpation and dental laboratory were higher in the graduated college group than the graduated highschool group. 4. By personal health state, the highest degree item of the satisfaction of occpation was the health group(Mn, 3.25). The highest degree item of the satisfaction of laboratory was the unhealthy group(Mn, 3.07). 5. By religion, the satisfaction if iccupation of laboratory ws higher in the religious group than the non-religious group. 6. By job career, the highest degree item of occupation satisfaction was 15 to 20 years group(Mn, 3.27), the lowest degree item was 20 and over group(Mn, 3.02). The highest degree item out of the satisfaction of laboratory was 15 to 20 years group(Mn, 3.05), The lowest degree item was 7 to 10 years group (Mn, 2.90). 7. By job position, the highest degree item out of satisfaction of occupation was the chief of laboratory group(Mn, 3.33), the head of laboratory group was the lowest degree item(Mn, 3.07). The hightest degree item out of the satisfaction of laboratory was the head of laboratory group(Mn, 3.10), the lowest degree item was the chief of laboratory group(Mn, 2.88). 8. By the place of employment, the degree of occpational satisfaction by items was found that the highest degree in the group engagel in general hospital(Mm, 3.43), the group engaged in dental clinic and hospital(Mn. 3.24), and the dental laboratory group(Mn. 3.14) in order. The difference among the group was significant emough(P<0.05). The highest degree item out of the satisfaction of laboratory was dental laboratory group(Mn. 2.70). The difference among the group was significant emough(P<0.01). 9. By monthly salary, the highest degree item out of the satisfaction of occupation was ￦500,000 to 600,000 group(Mn. 3.32), the lowest degree item was ￦600,000 and over group(Mn, 3.07). The highest degree item out of the laboratory satisfaction was ￦100,000 to 200,000 group(Mn, 3.03), the lowest degree group was ￦300,000 to 400,000 group(Mn, 2.95). 10. As compared with the degree of satisfaction according to job satisfaction, the highest degree item out of the occupational satisfaction was much satisfied group(Mn, 3.65), the lowest degree item was non-satisfied group(Mn, 2.68). The difference among the group was significant enough(P<0.05). The highest degree item out of the satisfaction of laboratory was non-satisfied group(Mn, 30.9), the lowest degree item was satisfied group(Mn, 2.84). The difference among the group was significant enough(P<0.01).

레진의치상 수리 시 인공타액 흡수도에 따른 결합강도 연구

강명호,이명곤,Kang, Myung-Ho,Lee, Myung-Kon 대한치과기공학회 2011 대한치과기공학회지 Vol.33 No.1

Purpose: There are some advantages of the acrylic resin denture base ; appropriate strength, volume safety, simple processing apparatus, and low cost. But, it have a weakness for fracture by intense pressure or shock. However, the repairs for resin denture base are possible using various materials and techniques. There is a few studies in repairs for resin denture base, but not clinical researches. And there is no studies in absorbed saliva into the region of fracture and bond strength. This study is to observe re-bond strength of resin denture base after repairing under saliva absorption. Methods: The samples were made of heat curing resin and the rectangular parallelepiped specimens which were 50mm long, 10mm wide and 3mm high. The four different groups immersed in the artificial saliva for 2 weeks were prepared, 1) no repaired control samples, 2) immediately repaired samples, 3) repaired samples after 1 day dry, and 4) repaired samples after 3 days dry. The prepared samples were repaired by two different curing materials, self curing resin and heat curing resin method. Each groups composed of 10 specimens were experimented with the three point bending tests for bonding strength measuring Results: There were under condition absorbed in the artificial saliva and repaired by self curing resin method, repaired specimens after 1 day and 3 days dry groups had higher values of bonding strengths than control group, and bonding strengths of immediately repaired samples were similar to those of control samples (p<0.05). There were under condition immersed in the artificial saliva and repaired by heat curing resin method, immediately repaired samples showed similar values to bonding strengths of control groups, and repaired samples after 1 day and 3 days dry groups were lower than those of control group (p>0.05). Conclusion: In this study, the repairs for resin denture base were remarkably high values of bonding strengths than those of the past, and showed that have stable bonding strengths independent of saliva absorption of denture base, so present repairs for resin denture base can be performed, regardless of saliva conditions.

도재용착용 비귀금속과 열가압성형도재의 전단결합강도 연구

김성수,김욱태,이명곤,Kim, Seong-Soo,Kim, Wook-Tae,Lee, Myung-Kon 대한치과기공학회 2011 대한치과기공학회지 Vol.33 No.1

Purpose: Heat pressed ceramics, used for all ceramic restorations, have the additional advantage of being technically less change through using of the lost-wax technique. Conceptually, combining the ceramic with the clinically proven reinforcing ability of a metal framework would be advantageous; however, cause of mismatching of fusion between ceramics and metal frameworks which from differences of casting temperature and coefficient of thermal expansion, pressed ceramics could not be used with a metal framework. The purpose of this study was to compare shear bond strength of press-to metal ceramic to porcelain fused non precious metal and feldspatic porcelain fused non precious metal. Methods: The 30 metal specimens were casted in a porcelain fused non precious metal nickel-chromium alloy. They were divided into 3 groups by surface treatment and applied ceramic: $125{\mu}m$ aluminium oxide sandblasting and veneered feldspatic porcelain (group FP), $125{\mu}m$ aluminium oxide sandblasting and had press-to-metal ceramic applied (group PC), porcelain bonder (gold bonder) fused on surface of metal specimens and had press-to-metal ceramic applied (group PCG). In each group 10 metal specimens were used. The press-to-metal ceramic applied 20 specimens had ash-free wax pattern applied, the metal-wax complexes invested, and were pressed with heat press ceramic. All specimens were subjected to shear bond strength test at a crosshead speed of 1.0 mm/min. Results: The results of measured in Mean SD and data were analyzed by one-way AVOVA (p= .05) and Tukey HSD test (p= .05).: group FP $16.090{\pm}1.841$ MPa, group PC $12.620{\pm}1.8256$ MPa, group PCG $10.920{\pm}0.9283$, significant differences between all groups (p < .05). Significant differences were found in each between group FP and group PC, group FP and group PCG (p < .05). Conclusion: The shear bond strength of press-to-metal ceramic to porcelain fused non precious metal was described higher in unused gold bonder group than used gold bonder groups.

간헐적 정수압이 세포의 부착에 미치는 영향성 평가

김영직(Young Jick Kim),이명곤(Myung-Kon Lee),박수아(Su A Park),신호준(Ho Joon Shin),김인애(In Ae Kim),이용재(Yong Jae Lee),신지원(Ji Won Shin),신정욱(Jung-Woog Shin) 한국정밀공학회 2005 한국정밀공학회 학술발표대회 논문집 Vol.2005 No.10월

In this study, effects of IHPs with various resting times to cell adhesion were investigated through the measurements of cell adhesive force, number and area of focal contacts (stained vinculin spots), and projected cell area, perimeter and circularity. In addition correlation tests and curve estimations using the experimental results were performed for the finding an essential factor for increment of cell adhesive force. In the results, immediately after mechanical stimuli (150 minutes after seeding) and one hour later (210 minutes after seeding), the average adhesive force of experimental group 5 (resting time: 15min) compared with that of control group at same culture time was increased significantly (p<0.05). Average projected area and perimeter of cells at Group 5 were increased significantly (p<0.05), while average circularity of cells at Group 5 incubated for 210 minutes was decreased significantly (p<0.05). In the digital image analysis of focal contacts containing vinculins, area and numbers of focal contacts per cell at Group 5 were higher than those of the other groups. This study indicated that IHP with appropriate resting time could contribute in improving cell adhesive force, cell spreading, development of cytoskeleton and formation of focal contacts. And cell adhesive force was correlated to the morphological aspects of cell and development of focal contacts. Particularly, area of focal contacts was closely related to cell adhesive force.