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Polyphosphate가 Porphyromonas endodontalis의 성장에 미치는 영향에 관한 연구
최성백,최호영,민병순,박상진,이진용,최기운 大韓齒科保存學會 1998 Restorative Dentistry & Endodontics Vol.23 No.1
Polyphosphate has been used to prevent decomposition of foods and has been shown to have inhibitory effect on the growth of gram positive bacteria. The purpose of this study was to evaluate the effect of polyphosphate on the growth of Porphyromonas endodontalis, a gram negative endodontopathic bacterium. Porphyromonas endodontalis ATCC 35406 was grown in the presence of polyphosphates with different chain lengths. Inhibitory effect of each polyphosphate which was added at the beginnig or during the culture, was determined by measuring the optical density of the bacterial cell at 540nm and by viable cell count. The results from this study were as follows : 1. Polyphosphates were shown the growth inhibition of the Porphyromonas endodontalis. 2. The minimal inhibitory concentration(MIC) of polyphosphate was observed to be 0.04%. 3. Polyphosphates with chain lengths of 25 and 75 demonstrated the greatest inhibitory effect on the growth of Porphyromonas endodontalis. 4. Polyphosphates are bactericidal to Porphyromonas endodontalis, demonstrating the growth inhibition of the bacterium. The overall results suggest that use of polyphosphate may affect the growth of Porphyromonas endodontalis. Further studies will be needed to confirm the effect of Polyphosphate.
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근관충전용 글라스 아이오노머 시멘트의 근단 폐쇄성과 치질 적합성에 관한 연구
김현아,최기운,민병순,최호영,박상진 慶熙大學校 齒科大學 1995 慶熙齒大論文集 Vol.17 No.2
The purpose of this study was to compare the apical leakage and adaptation to the dentinal wall of a glass ionomer root canal cement(Ketac-Endo) with those of AH-26 and Tubli-Seal. 102 single-rooted teeth were insrumented with step-back technique and randomly divided into four groups according to kinds of root canal cements: Ketac-Endo, AH-26, Tubli-Seal, and no root canal cement. Four experimental groups were as follows; Group 1 Filling with gutta-percha and Ketac-Endo Group 2 Filling with gutta-percha and .AH-26 Group 3 Filling with gutta-percha and Tubli-Seal Group 4 Filling with gutta-percha without root canal cement All the specimens were obturated with lateral condensation technique, and stored in 100% humidity for 4 days. 20 teeth in each group were placed in centrifuge tube filled with India ink, and then centrifuged for 20 minutes at 3,000 rpm. And they were evaluated for linear dye leakage using a stereoscope and analyzed by one-way ANOVA. 22 teeth were split longitudinally and evaluated the adaptation to the dentinal wall using scanning electron mrcroscope(4 teeth in each group) and stereoscope(2 teeth in 1, 2, 3 group). The obtained results were as follows ; 1. In case of not used root canal cement(Group 4), there was showed much degree of dye penetration comparerd with used root canal cements (Group 1, 2, 3)(P<0.01). 2. In the case of used root canal cements(Group 1, 2, 3), there was no significant difference in linear leakage in groups(P>0.01). 3. In the case of used root canal cements(Group 1, 2, 3), there was showed intimate adaptation to the dentinal wall independent on kinds of root canal cements. 4. Fractured surfaces indicated failure of cohesion in Ketac-Endo, and failure of adhesion to dentine in AH-26 and Tubli-Seal. 5. According to similar apical leakage and adaptability to the dentinal wall to another root canal cements, it is possible to be used glass-ionomer cement as root canal cement.
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Streptococcus salivarius의 요소분해효소 활성에 관한 연구
정상백,최호영,민병순,박상진,이진용,최기운 大韓齒科保存學會 1998 Restorative Dentistry & Endodontics Vol.23 No.1
Dental caries is induced by organic acids produced by oral bacteria. In order to prevent dental caries, therefore, it is essential to maintain neutral pH in the oral cavity. Urea plays a major role in oral pH homeostasis. Urea is hydrolyzed by bacterial ureases to ammonia, causing a pH elevation, Streptococcus salivarius has been shown to be a major contribution to oral ureolysis. Synthesis of urease by S. salivarius appears to be constituitive, but can be greatly enhanced by low pH. It is, therefore, conceivable that ureolytic activity of S. salivarius from a carious lesion is greater than that of the bacterium from a healthy tooth. In the present study, urease activity of S. salivarius isolates from dental plaque of carious lesions was compared with that of the isolates from plaques of the teeth and the dorsum of the tongue; 45 S. salivarius strains were isolated from carious lesions(>C2) of 21 individuals with dental caries and 30 strains from 10 individuals without dental caries. The results were as follows: 1. All the 21 individuals with dental caries harbored ureolytic S. salivarius whereas 3 of 13 individuals without dental caries harbored non-ureolytic strains of S. salivarius. 2. All the 45 S. salivarius isolates from carious lesions showed urease activity. In contrast, of 30 isolates from individuals without dental caries, 17 isolates(56.7%) did not demonstrate urease activity, or if any, very little(<5μmol/min/mg). 3. Urease activity of the isolates from carious lesions was greater than that of the isolates from individuals without dental caries:the urease activity ranged from 42 to 381μmol/min/mg and from 0 to 208μmol/min/mg, respectively. 4. At acid pH(5.5), the isolates which showed intermediate urease activity at pH 7.0 demonstrated even higher activity whereas the isolate with no or lower urease activity did not show any significant difference in their activity. However, the isolates with the greatest urease activity from both individuals with and without dental caries, exhibited a rather much lower urease activity at pH 5.5. The overall results suggest that isolates may have their own urease activity but the isolates exposed to chronic acidic environment of the carious lesion might elevate urease activity of S. salivarius, which in turn, might influence on survival of S. salivarius itself and other bacteria establishing a new oral bacterial ecosystem.
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표면처리된 복합레진에 대한 수리용 레진의 결합강도에 관한 연구
강현숙,최호영,민병순,박상진,최기운 慶熙大學校 齒科大學 1995 慶熙齒大論文集 Vol.17 No.1
Composite resin repair requires strong bond strength between the new and old materials. The objective of the current study was to identify the optimal treatments for sufficient bond strengths. Bondings between same kinds of materials and cross bondings using chemical curing composites and light curing composites were tested. Surface treatments included the methods of sand-blasting, acid etching and coating of bonding agent. Seven kinds cases of combinations from three kinds of methods were experimented and compared with a control group of which surfaces were highly polished. Measurements of shear bond strength and observations of surface morphologic changes using a scanning electron microscope were done. Following conclusions were drawn 1. The highest bond strength among composite resins were exhibited by the treatment of the sand-blasting and the coating of bonding agent. 2. Acid etched surfaces showed the lowest bond strength. Bond strengths obtained from experimental groups including acid etching were lower than those obtained from same kinds of experimental groups without acid etching. 3. Simple method of the coating of bonding agent produced the slightly increased bond strength on chemical curing composite and reduced bond strength on light curing composite. 4. Bonding surfaces of chemical curing composite resin showed slightly higher bond strengths than light curing composite resin, however significant differences were not confirmed statistically. 5. More significant irregular surfaces were created by sand-blasting method than acid etching method. 6. A principal component of fillers of both resins was silicon. Acid etching method produced the seperations and degradations of fillers, these were significant on light curing composite resins which containing barium fillers.
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부착단백질이 사람 치수세포의 부착 및 증식에 미치는 영향에 관한 연구
신영주,최호영,민병순,박상진,최기운 慶熙大學校 齒科大學 1995 慶熙齒大論文集 Vol.17 No.2
The purpose of this vitro study was to evaluate attachment and proliferation of human pulpal cells to the attachment glycoprotein-coated and non-coated culture dishes. Well known adhesive glycoproteins were used, such as type I collagen, type IV collagen, fibronectin, laminin, and vitronectin. Each adhesive glycoproteins applied onto the culture dishes. In this study, the protein coated and non-coated dishes were classified as each groups. Human pulpal cells cultured onto each culture dishes. After 90 minute, 4 hour and 24 hour incubation attached cells in each group were counted with hematocytometer for evaluation of the attachment of human pulpal cells. The configurations of attached human pulpal cells were done by SEM observation. The results as follows 1. After 90 minute incubation the score of attachment of human pulpal cells was best in laminin-coated group among groups. Then fibronectin, type IV collagen group were better, and allproteins were higher than control. 2. After 4 hour incubation the numbers of attachment of human pulpal cells were most in fibronectin coated group. 3. After 24 hour incubation all of adhesive glycoproteins showed high and similar attachment effect to human pulpal cells. 4. In SEM observation, fibronectin and type IV collagen groups showed well spreaded human pulpal cells, then laminin group was moderately spreaded, and vitronectin group was mildly spreaded as well as control group.
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