정상교합인의 두부위치변화에 따른 교합접촉점의 변화에 과한 연구

최희철,이성복,최대균,박남수 慶熙大學校 齒科大學 1994 慶熙齒大論文集 Vol.16 No.1

The understanding the nature of occlusal tooth contacts of natural dentition is important for correct diagnosis and treatment of diseases developed in stomatognatic system. Several investigator have studied the distribution of tooth contacts in maximum intercuspation and have repored contact locations with respect to the tooth position. However, there are few report the variation of the occlusal contact point with change in each head position. This study analysed the number of occlusal contact point with change in each head position. 30 subject(male 17, female 13), who had natural occlusion and no symptoms of temporomandibular disorder, were selected. The numbers and patterns of tooth contact were recorded by silicone bite registration on stone model at four different head positions with head anguration gauge(from the supine to the upright position). The results obtained were as follows: 1. The numbers of total occlusal contact point on teeth increased to average 25, 29, 35, 42 points as head angulation was changed from the supine to the upright position against the ala-tragus line, and there was significant difference (P<0.05) 2. In the 19 subject(65%) of total 30 subject, the perforated point of the silicone bite indicated that the locus for the prime contact point moved mesially as the head angulation was changed from the supine to the upright position. 3. On the basis of the fact that the anterior occlusal contact point increase as head angulation changed from the supine to the upright position,we could find that the mandibular position is moved anteriorly.

토양미생물을 이용한 하수의 질소제거효율 향상

최영균,오동익,이종영,손대희 대구대학교 환경기술연구소 2005 미래환경기술 Vol.1 No.2

The effect of humus soil on biological denitrification was investigated through NUR batch tests. Specific denitrification rate of HMLE(Modified Ludzack Ettinger process combined with Humus soil contactor) and CMLE(Control Modified Ludzack Ettinger process) sludges as well as COD consumed for denitrification could be estimated from the batch tests. Two linear phases of denitrification rate could be observed when acetate was used as a carbon source. However, denitrification behavior was composed of three linear phases when a primary settled municipal wastewater(PW) was used as a carbon source. The specific denitrification rates on SBCOD(slowly biodegradable COD) fraction in raw wastewater were estimated 4.82 and 3.73 mg N/g VSS·hr when HMLE and CMLE sludge was used as a seed sludge. It means that the hydrolysis rate of HMLE sludge on SBCOD fraction was higher than that of CMLE sludge. Actinomycetes, one of the soil microorganisms, was estimated 150,000 actinomycetes/ml in the biomass of HMLE process, which was 10 times higher than that of CMLE process. Actinomycetes was well known for its distinguished hydrolyzing ability on particulate organic matter. Almost of input COD was utilized for denitrification and cell synthesis when HMLE sludge was used as a seed sludge in NUR batch test. While, about 70% of input COD was comsumed when CBNR sludge was used. It means that substrate utilization rate, especially SBCOD utilization rate, of HMLE sludge was higher than that of CMLE sludge.

생물막 공정에서 질소제거효율 향상을 위한 유기성담체의 효용성 검토

최동욱,최영균,김대영,김윤중,정태학 대한상하수도학회 2003 상하수도학회지 Vol.17 No.3

Availability of organic media for improving nitrogen removal efficiency in a biofilter process was studied. Although, aerobic and anoxic phase could be clearly divided during the operation of single-stage biofilter process and nitrification efficiency was about 80%, denitrification efficiency was very low due to depletion of organic substrate in anoxic phase. However, the deficiency could be improved by addition of organic media in anoxic phase from the simulated result. Nitrogen removal efficiency in a biofilter process packed with organic media in anoxic phase was predicted to be 29% higher than that packed with inorganic media. In addition, about 79% of nitrogen removal efficiency could be obtained from a column test using organic media innoculated by activated sludge. Improvement in nitrogen removal efficiency was responsible for organic leaching from the organic media and the leaching rate was 0.21㎎COD/g-org.media/day.

로자탄 대 포시노프릴의 고혈압 환자들에서 항고혈압 효과, 안전성 및 내약성의 비교

박대균,이명묵,채인호,이무용,이홍자,김효수,김철호,손대원,오병희,박영배,최윤식 대한순환기학회 1998 Korean Circulation Journal Vol.28 No.1

생물학적 질산화를 이용한 제올라이트 재생을 위한 기초 연구

손대희,최영균 대구대학교 환경기술연구소 2005 미래환경기술 Vol.1 No.2

Zeolite is well known material for its ability to preferentially remove ammonium ions from wastewater. However, its usage has been limited by high cost for chemical regeneration on this purpose. As an alternative, biological regeneration of zeolite has been suggested by some researchers. In this study, the characteristics of biological regeneration of zeolite was studied at various conditions, i.e. changes in microorganism and Na^(+) concentration. In the first test, the percentage of bio-regeneration via nitrification in the columns (MLVSS 2,250 mg/ℓ and 4,500 mg/ℓ) was 2.6 times higher than the column with NaHCO3 (2,980 mg/ℓ) addition only. In the second test, MLVSS were changed (400, 800 and 3,200 mg/ℓ) but, for alkalinity supply, NaHCO3 concentration was fixed at 745 mg/ℓ. The regeneration rates were proportional to the MLVSS concentration, but the same amounts of total regenerated nitrogen were achieved in all columns tested. In the third test, the regeneration tests were performed to evaluate effects of Na^(+) concentration on regeneration were tested. The regeneration efficiency was enhanced about 5% when Na^(+) concentration increased from 342 to 734 mg/ℓ. There was no difference in regeneration rate by nitrification. Therefore the higher regeneration efficiency of zeolite could be obtained by nitrification than by chemical methods. The regeneration rates with the fixed Na^(+) concentration were proportional to nitrification rate, and the regeneration efficiencies with the fixed microorganism concentration were highly dependant on cation concentrations such as Na^(+).

전치 유도각의 인위적 증가에 의한 저작근과 하악 운동 양상의 변화에 대한 연구

이용식,최대균,최부병 慶熙大學校 齒科大學 1995 慶熙齒大論文集 Vol.17 No.2

This study' was performed to measure the changes of the mandibular movement and the masticatory muscular activities anterior temporal and masseter muscle of both side - reflected by intentional increase of anterior guidance angle. For this study, 5 volunteers (3 males and 2 females with average age of 24.0) were selected. Each volunteer had Angle's classification I and did not have any missing tooth except third molar and any extensive restorations. Metallic guide plate was made at volunteer's working model fabricated by improved dental stone and cemented to the palatal surface of maxillary central incisor using resin cement(Panavia 21�) and then adjusted not to give any occlusal interferences at intercuspal position. The activity of masticatory muscles and the changes of mandibular movement were recorded by EMG and Sirognathograph in Biopak analysing system(Bioresearch Inc., Milwaukee, Wisconsin, USA). Measurement was done at before experiment, irnmediatley after placement, 1 week after placement, immediately after removal, and 1 week after removal. The results were as follows: 1. Moderate phonetic disturbance and mild headache were occured to 3 volunteers for 2 days after setting and l volunteer had positive reaction to percussion and slight midline diastema. But all of these clinical signs were diappeared 1 week after removal and the other volunteer did not have any special clinical sign. 2. In the EMG of the mandibular rest position, the mean value of anterior tempotal muscle was increased immediately after placement(p<0.01) and then decreased 1 week after placement(p<0.05) and increased 1 week after removal(p<0.05) but not recovered as before experiment. The mean value of masseter muscle was decreased during the experiment period: 3. In the EMG during mandibular protrusive movement, all muscular activity was decreased during the experiment period. Reduced activity was not recovered I week after? removal(p<0.05). 4. During the habitual opening, anteroposterior movement of mandible was decreased immediately after place ment(p<0.05) and then increased 1 week after placement but not statistically significant(p>0.1). Vertical movement was not shown significant difference during the experiment period(p>0.1). Lateral movement was decreased immediately after placement(p<:0.05) and then increased 1 week after placement but not recovered as before experiment. The opening and closing velocity of mandible was shown minor changes but not statistically significant. 5. During the habitual opening, anteroposterior movement of mandible was decreased 1 week after placement(p<0.(6) and then increased immediately after removal and recovered 1 week after removal as before experiment. Vertical movement was not shown significant changes. Lateral displacement of mandible was increased continuously and recovered 1 week after removal. Opening velocity was temporarily increased immediately after removal but recovered and closing velocity was not shown significant changes. 6. During the right side chewing, anteroposterior movement of mandible was increased immediately after removal but recovered and vertical movement was not shown statistically significant results. Lateral displacement and velocity o mandible were not shown significant results. 7. During the left side chewing, the changes of mandibular movement pattern were not shown statistically significant results.

복합레진의 중합 수축력과 수복물의 결합양상에 관한 연구 제 1 편 : 중합수축력

박남수,최대균,임호남,최부병,우이형 大韓齒科器材學會 1993 대한치과재료학회지 Vol.20 No.1

The polymerization contraction forces has a relationship with the contents of filler, and if forces surpass the bond strength between restoration and bonded surface, the failure of bond can be occured. This study was designed to evaluate the effects of filler contents on the polymerization contraction forces and to confirm whether the polymerization forces could induce the bond failure of composite resins to enamel or dentin. Low capacity load cell using strain gauge were prepared and used as a measurement system for polymerization contraction forces. Oxidized alloy surfaces, enamel surfaces and dentin surfaces were used as bonded surface. Measurements of the polymerization contraction forces were done for 1 hour, and a stress at 1 hour after was recorded as a polymerization contraction force. It was considered as a bond failure that the polymerization contraction forces increased and then decreased by the time. The following conclusions were drawn : 1. Polymerization contraction forces of composite resins were decreased by the increase of filler contents. 2. Polymerization contraction forces were increased at thickened resin specimens, but it was not significant at over two millimeter thickness. 3. Bond strength of composite resins to the acid etched enamel surfaces exceeded the polymerization contraction forces and the reduced polymerization contraction forces due to the bond failure were not confirmed. 4. Failure of bond and reduced polymerization contraction forces occured on dentin.

정상인과 체육인의 교합상태에 대한 정성적·정량적 비교 연구

장정미,최대균,이성복 慶熙大學校 齒科大學 1995 慶熙齒大論文集 Vol.17 No.2

This study was accompolished to analyze and compare the number and area of the occlusal contact points in healthy volunteers and athletes with nonrial occlusion. For this study, 15 athletes(13 amles and 2 females with average age 20) and 21 healthy volunteers(14 mles and 7 females with average age 20.09) were selected. The visual display acquired by scanning of occlusal record in maximal intercuspation was converted into 16 gray value image. Then, using computer program(] & Lee Occlusal Analyser), the pixel which was in definite range of the gray value was recognized, and the numbers of recognized pixel were calculated to area. The results were as follows ; 1. The average numbers of total alusal contact points were 31.05 in control group, and 34.67 in athlete group. The average area of total occlusal contacts was 100.25mm2 in control group, and 127.78mrn in athlete group. 2. In control group, the average numbers of occlusal contact points were revealed in order as follows the first molar(8.48). the secondmolar(8.24), the second premolar(4.71), the lateral incisor(2.90), the first premor(2.43), the central incisor(2.19), and the canine(2.1). The least average in canine(2.1) was similar to the average(2.19) in central incisor and (2.09) in lateral incisor. In athlete group, the average numbers of occlusal contact points were revealed in order as follows ; the first molar(8.87), the secondmolar(8.47), the second premolar(5.60), the canine(3.80), the lateral incisor(3.33), the first premnolar(2.67), and the central incisor(1.93). 3. In ' control group, the average areas of occlusal contact surface were revealed in order as follows ; the first molar(39.47mm'), the second molar(37.54mu>'), the second premolar(9.541d) the first premolar(6.18mm'), canine(3.49mn?), the central incisor(2.76mn?), and the lateral incisor(1.28mm'). In athlete group, the average areas of occlusal contact surface were revealed in order as follows ; the first molar(44.l1mm'), the second molar(40.69mm'), the second premolar(16.50mm'), the first premolar(9.39mm'), the canine(5.08 mm'), the lateral incisor(3.7mni), and the central incisor(2.25mmT 4. With aging in both control and athlete group, there was a decreasing tendancy in average number of occlusal contact point, and was an increasing tendancy in average area of occlusal contact surface. In comparison at each age, both the numbers and area of occlusal contact were greater in athlete group than in control group. It was not significant in the numbers of occlusal contact points beween athlete and control group(p>0.1), but significant in the area of occlusal contact surface(p<0.05). 5. In comparision as to the kind of sports(Gymnastics : 2, Rugby : 3, Soccor : 5, Ice hocky : 5), the numbers Of occlusal contact points were the most in ice hocky, and the area of occlusal contact surface was the greatest in gymnastics. With increasing a career in athlete group, there was a decreasing tendancy in average numbers of occlusal contact points and was an increasing tendancy in average area of occlusal contact surface. By 'I'-scan analyzing, the contact numbers on the anterior teeth were greater in control group than in athlete group, and on the posterior teeth were greater in athlete group than in control group. And the results aquaired by T-scan were lesser than that aquaired by the silicone bite records. It was not significant in the posterior teeth, but significant in the anterior teeth. In T-scan records, the numbers of occlusal contact points on second molar were the greatest, but rn the silicone records, the numbers on first molar were the greatest.

복합레진의 중합 수축력과 수복물의 결합양상에 관한 연구 제 3 편 변연누출과 틈새

박남수,최대균,임호남,최부병,우이형 大韓齒科器材學會 1993 대한치과재료학회지 Vol.20 No.2

This study was designed to confirm the influence of the polymerization contraction stress to the marginal leakage and gaps of resin restorations. Ten kinds of experimental composite resins were prepared with varing the filler contents to display the different polymerization contraction stress. A cavity with enamel and dentin margins were prepared on the cervical area of human tooth. Enamel margins were etched with 37% phosphoric acid for 1 minute. Experimental composite resins were filled into the cavities and immersed in water bath of 37±1℃ for 24 hours, and then immersed into dye solution. Tooth were cut through the restoration, and the infiltration of dye was observed. Marginal gaps were measured on the light microscope with 100 magnifications. The following conclusions were drawn : 1. Polymerization contraction stress and gaps showed the corelation between them, gaps were decreased by increase of filler contents. 2. There was not exist the relationships between polymerization contraction stress and marginal leakage. 3. Marginal leakage and gaps were larger at dentinal margins than enamel margins.

임플란트 보철치료

권긍록,최대균 경희대학교 2000 慶熙醫學 Vol.16 No.2