• Restorative Dentistry and Endodontics
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• 제19권2호
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• pp.409-428
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• 1994

Endodontic surgery is performed when conventional endodontic therapy fails or is contraindicated. In such cases, retrograde filling materials including amalgam, composite resin, and various cements have been used. Biocompatibilty and margin sealing ability of retrograde filling materials are important for the long term success of endodontic surgery. In vitro cell culture is frequently used as the method of measuring the biocompatibilty of dental materials. The purpose of this study was to evaluate the cytotoxicity of six kinds of retrograde filling materials including newly developed light curing glass ionomer cements. Each material was mixed according to. the manufacture's instruction and evaluated as : freshly mixed, 24-hour after mixing, and 168-hour after mixing respectively. The elution solution was extracted after 24-hour contact with materials using media. Cytotoxicity was evaluated by direct contact, or elution contact. Test results of radiochromium($^{51}Cr$) release, cell viability using tetrazolium dye (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl dimethyltetrazolium bromide(MTT) test and lactate dehydrogenase(LD) of damaged L929 cells were analyzed. In the $^{51}Cr$ release of direct contact, all experimental retrograde filling materials except amalgam and glass ionomer cement showed increased cytotoxicity compared to control. In the $^{51}Cr$ release of elution solution, the released $^{51}Cr$ was so minimal that it was impossible. to evlauate the cytotoxicity exactly. The elution solutions of glass ionomer cement and IRM showed marked cytotoxicity in MTT test. LD enzyme activity was highest in tests of direct contact with composite, light curing composite, and light curing glass ionomer cement and IRM. Amalgam revealed least cytotoxicity while IRM showed cytotoxicity using all three methods. Composite, light curing composite and light curing glass iomomer cement were cytotoxic in the tests of $^{51}Cr$ release and LD activity. Glass ionomer cement showed cytotoxic effect only in the MTT method. From these results it is suggested that the standardization and optimization of cytotoxicity testing, especially using elution solutions, should be strongly advised.

• Restorative Dentistry and Endodontics
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• 제46권3호
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• pp.34.1-34.9
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• 2021

Objectives: This study aimed to assess the presence of pulp stones through an examination of cone beam computed tomography images and correlate their prevalence with age, sex, dental arch and side, tooth type, and restoration type and depth. Materials and Methods: Cone beam computed tomography images obtained from 673 patients and archival data on 11,494 teeth were evaluated. The associations of pulp stones with age, sex, dental arch and side, tooth type, and restoration type and depth were noted. All the measurements were subjected to a χ² test and one sample χ² test (p < 0.05). Results: In the study group, 163 (24.2%) patients and 379 (3.3%) teeth had at least one pulp stone. The pulp stone frequency in those aged 30-39 years was significantly greater than in those aged 18-29 and ≥ 60 years, and the frequency was higher in females than in males (p < 0.05). The highest prevalence of pulp stones was found in maxillary dental arches and molar teeth (p < 0.05). Pulp stones were significantly more common in medium-depth restorations (p < 0.05). Conclusions: Maxillary molar teeth, medium-depth restorations, individuals aged 30-39 years and females had a greater percentage of pulp stones.

• 보건교육건강증진학회지
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• 제17권1호
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• pp.95-113
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• 2000

The purpose of this study is to investigate the state of the dental health of adults, used self-reporting qestionnaire as objects of 923 residents living in nine districts at random among the sites of eleven town located in a County. The level of knowledge on dental health of adults in a County was 65.6 points out of 100 points, comparatively low. Accodingly, it is necessary for entire adults to have a dental health-related education and get high standard of knowledge. Especially, educational approach should be performed for groups of 40-49 years old, 50-59 years old, above 60 years old, male, no educational background, having only elementary and middle school education, not having any jobs, engaging in agriculture, doing business on their own and so on. When planning the contents of health education, one actually has to include the habit of amalgam, the factor in influencing on dental health as well as show an example such as how to brush teeth, checking point of proper brushing, how to grip toothbrush. The attitude score related to dental heath was 71.2 points out of 100 points, relatively low. Consequently, the change of attitude related the dental health among entire adults is necessary, particularily, the strategical approach is essential to change dental health connected to attitude positively for groups of male, having high school education background, office workers and the civil service. Besides, among dental health related symtoms, more that 30-40％ of objects showed negative attitude toward as the following cases; in case that plaque or food debris are attached to the teeth (40.8％), upper and lower teeth do not fit together(40.3％), you cannot sleep well because of toothache(31.0％), more than one tooth fall out(31.0％), you have loosing teeth(30.6％), the approach should be conducted to form attitude that dental care is necessry. The state of dental health through dental health related symtoms was 33.3 points out of 100 points, which was fairly satisfactory. However, dental treatment for the state of dental health should be executed in case of comparison of the dental health state according to general characteristics, the group who are above 60 years old, have elementary school education background, engage in aggriculture who are not good in dental health state as opposed to other groups. Furthermore, there should be dental care needs according to dental health related symtoms, particularly, more than 60-70％ of objects have experienced symtoms that plaque or food debris attached to the teeth, tartar is on the teeth so dental treatment should be peformed for a large number of adults. In addition, for the people who have indications that there was a cavity, more than one tooth loss, chilled teeth, toothache when chewing, loose teeth, upper and lower teeth do not fit together, you cannnt sleep well due to the toothach, etc, there should be care through dental treatment. The actual conditions of the hygine of the mouth was relatively good and the difference of the actual state of dental health care in terms of general characteristics showed in only gender; female was more careful in dental health. Comparing the state of oral health synthetically, when they have symtoms, only 34.8％ of objects go to a dentist, 60.7％ are using passive or negative care such as gargling, tolerating or ignoring. There was many symtoms to care through dental therapy such as plaque or food debris get in between the teeth, tartar on the teeth, teeth are very cold, more than one tooth fallout, loose teeth, there is wrong amalgam, and so on, among symtoms to care passively or negatively. Therefore the education for proper treatment program should be performed. As a result of dental health-related knowlege, attitude, health state, verification of correlation between the actual condition of care, the higher the dental heath-related knowldege becomes, the more positive the dental health-related attitude is, and the state of dental health, that is, the standard of the symtom of dental health diminishes. the care for dental health executed through more active method and the more positive dental health-related attitude is, the more active means they performed. Consequently, the high level of dental health-related knowledge should be necessary, the more positive the dental health-related attitude was, the more active method they adopted, therefore, the program is needed to form attitude related to the dental health positively. As the knowledge on dental health is increasing, the attitude is also positive, after all, the plan to increase the standard of knowledge on dental health should be contrived through education program related to dental health.

• 대한소아치과학회지
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• 제11권1호
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• pp.159-167
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• 1984

In this experiments, the fracture loads were measured and analysed by using of Instron universal testing machine (Model 1132). With 80 upper and lower deciduous molars that were free of dental caries. Isthmus of teeth were prepared to 1/3 and 1/4 of intercuspal width, and internal line angles with round and sharp shape, and then amalgam restoration were performed. The results of this study were as follows; 1. Resistance to fracture loads were greater with isthmus of 1/3 intercuspal width than of 1/4 intercuspal width, especially, statistically significant difference on upper and lower second deciduous molars. 2. Resistance to fracture loads were greater with rounded internal line angle than sharp internal line angle. The above results were as follows, the fracture loads had greater resistance on isthmus of 1/3 intercuspal width, and rounded internal line angle, but normal physiological occlusal forces could permit isthmus of 1/4 intercuspal width and rounded internal line angle.

• Restorative Dentistry and Endodontics
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• 제16권1호
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• pp.87-105
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• 1991

The purpose of this experiment was to measure the leaking and solubility of commonly used dental restorative materials - Silux plus (CS), Hi-pol (CH), Clearfil F-II, Fissureseal (FS), Glass-Ionomer cement Fuji Type II (GI), Amalgam Cavex 68 (AM), Zinc Phosphate Cement (ZP) and gutta-percha (GP) and investigate the relation between the solubility and marginal leakage. Disc-shape specimens were fabricated with each material and dipped into deionized water, 0.01M lactic acid and 0.005M KOH solution, thus the total ionic concentrations in each solution was measured with ion chromatograph after 1, 3, and 7 days, respectively. For the solubility test, each specimen was immersed in 0.001M and 0.01M lactic acid for 24 hours, respectively and total weight loss was calculated. Also, Zn leaking through the margin of restorations was measured. The obtained results were as follows: 1. The amounts of eluted ion from the eight materials were most in 0.01M lactic acid and least in deionized water. 2. Of the eight materials, the fluoride release was greatest for glass ionomer cement (GI) in 0.01 M lactic acid after 7 days. 3. In analysis of the divalent cation, Mg was eluted most for zinc phosphate cement (ZP) and Ca for Clearfil F-II (CF) in 0.01M lactic acid after 7 days. 4. In analysis of transition metals, Cu and Zn were detected only. 5. The solubility rate of eight materials was greater in 0.01M lactic acid than in 0.001M for 24 hours, for zinc phosphate cement (ZP) the rate was greatest (5.4%) in 0.001M lactic acid, and amalgam least (0.01%). 6. The Zn concentration of restorative material with Z.P.C base was greater in 0.01M lactic acid than in 0.001M lactic acid.

• 대한치과의사협회지
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• 제36권2호통권345호
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• pp.144-150
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• 1998

The dental insurance had been enforced in Korea past 20 years. The major part of the insurance was filling, and the filling was divided into two parts-the cavity preparation and cavity filling, The Cavity filling was estimated into 6 levels according to the cavity types. But the tooth cavity preparations was not evaluated by the cavity types but merely only one-the one visit filling or cavity preparation. Korean dentists tend to turn away from the amalgam to the non-insurance treatments. The purpose of this study was to relate the cavity preparations and cavity fillings to the cavity types. So I measured the real time and surveyed the relative difficulties of cavity preparations from the 31 dentists according to the cavity types, who had been trained in conservative dentistry. The conclusion of this study was below. 1. The estimations of tooth cavity preparation was divided same as the cavity filling. 2. There must be reasonable considerations about the times and difficulties in cavity preparation. 3. There was differences between the premolars and molars, upper jaw and lower one. 4. Two or more cavities in one tooth must be evaluated according to the number of cavities, not in one cavity.

• Restorative Dentistry and Endodontics
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• 제6권1호
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• pp.123-132
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• 1980

The author conducted a dental survey of a college girl students and compared with that of E college students 10 years ago which based on the same criteria. The items of this survey included the prevalence of dental caries, DMFT and the kinds of restored material. All college students 1,414 were examined in May 1978, with the recommended criteria and method of W.H.O.. Among them, the data of 1,393 were analyzed for this study. The following results were obtained: 1. The average number of present teeth were 28.97${\pm}$1.64. 2. The prevalence of dental caries was 84.92% and D.M.F. index was 15.51. Average D.M.F. teeth were 4.49${\pm}$3.69. 3. The average number of decayed (D) teeth were 2.09${\pm}$2.16. 4.30% of the present decayed teeth was secondary decay, and 2.44% of the decayed teeth was indicated for extraction. 4. The average number of missing(M) teeth were 0.32${\pm}$0.79. It included 8.56% of root fragements. 5. Average number of filled(F) teeth were 2.09${\pm}$3.17. F-ratio of this group was 46.45%. The analysis revealed 50.88% of amalgam alloy, 31.41% of gold inlays, and 1.20%, the least among the filling materials, silicate cement or composite resin. 6. While the prosthodontic treatment, such as crown and bridge has reduced than that of 10 years ago, the fillings and inlays as the conservative means has increased.

• 대한치과의사협회지
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• 제15권11호
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• pp.757-761
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• 1977

The purpose of this study was to evaluate the marginal sealing ability of Hipol composite resin. Using freshly extracted human teeth and 2% acquous methylene blue, the marginal leakage of dye in restorative materials such as Hi-pol, Adaptic, Nuvasystem, Epolite and Amalgam was investigated at 37℃ and under temperature cycling between 4℃ and 60℃. The results were as follows; 1. All the filling materials revealed the penetration of dye between cavity walls and restorations. 2. Hi-pol and Adaptic showed more marginal leakage than other materials and the degree of dye penetration in Hi-pol was similar to that of Adaptic. 3. Nuva system showed the least marginal leakage at 37℃ and under temperature cycling between 4℃ and 60℃. 4. Under temperature cycling, all materials showed a slight increase in marginal leakage except Epolite, which showed the greastest change in leakage.

• 대한치과의사협회지
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• 제16권12호통권115호
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• pp.935-940
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• 1978

The purpose of this study was to evaluate the marginal sealing ability of 'Hi-Pol' Enamel Bond system. Using freshly extracted human teeth and 2% acquous methylene blue, the marginal leakage of dye in restorative materials such as 'Hi-Pol' Enamel Bond system, Hi-Pol, Adaptic, Nuva system, Epolite and Amalgam were investigated at 37℃ and under temperature cycling in range of 4℃-60℃. the results as follows; 1. All filling materials showed some degree of marginal penetration by 2% methylene blue dye. 2. 'Hi-Pol' Enamel Bond system revealed the least marginal penetration by 2% methylene blue as Nuva did at 37℃, but under temperature cycling in range of 4℃-60℃ it showed the greatest marginal penetration. 3. Hi-Pol restoration showed a tendency the similar to the other composite restoration. 4. Nuva system had the most effective marginal sealing ability either at 37℃ and under temperature cycling.

• 대한치과의사협회지
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• 제20권11호통권162호
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• pp.929-932
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• 1982

Calcium Hydoxide는 치수복(pulp capping), 생활치수절단술(vital pulpotomy)등에서 bactericidal effect 때문에 많은 사용을 하고 있으며, 최근에는 무수치(pulpless teeth)와 관련된 치근단병소가 있는 경우, 미완성치근단인 경우, 치근흡수, 횡주치근파절(Transverse root fracture)등의 경우에서도 Ca(OH)₂paste를 사용하여 성공적인 근관치료를 할 수 있다. 근관의 instrumentation 과 irrigation후 근과 dressing 은 약 1주일간 행하고 Ca(OH)₂paste를 건조된 근관내에 넣는다. 이때 치근단(root apex)으로부터 약 3~5mm 되게 저속으로 아주 가볍고 부드러운 압력을 가하여 Ca(OH)₂paste를 cotton pellet로 밀어넣고 Sealing(가봉)한다. 이 Temporary sealing은 1개월이상 견딜수 있도록 Cement 또는 Amalgam filling 함이 좋다. Ca(OH)₂paste의 제법은 normal irrigating agents 와 minimal filing으로 시행한다.