• Environmental Analysis Health and Toxicology
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• v.22 no.3
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• pp.247-254
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• 2007

This study was performed with the questionnaire survey on mercury knowledge and mercury exposure avoidance behavior, which was conducted among 1076 dental personnel in September, 2004. As for the factors effecting the mercury knowledge, it seems that they are closely related with the personnel's educational backgrounds, and their understandings of causing environmental hazardousness in the dental offices. And also, the factors effecting the behavior of mercury exposure avoidance are strongly connected with the knowledge points on mercury, the knowledge of air states in the dental clinic offices, the use of pincettes and gloves in squeezing, and rubber dam and gloves in mulling, the experience of environmental education on mercury, etc. In the survey, the higher points in mercury knowledge is closely related with the higher points in the behavior of mercury exposure avoidance. Nevertheless, the very fact that the lower points in the behavior among personnel takes on the aspect of the relatively higher points in knowledge on mercury may be understood that the generally acquired knowledge on mercury cannot be the critical factor of the behavior of mercury exposure avoidance.

• The Journal of the Korean dental association
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• v.23 no.3 s.190
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• pp.229-235
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• 1985

• The Journal of the Korean dental association
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• v.11 no.3
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• pp.185-189
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• 1973

Dental amalgam in the clinic practice of dentistry is one of the most important materials. Mercury, one of the component of this alloy, is emitted in the form of vapor after filling as long as 5 days Silver particles penetrate into the dentine deeply along the tubles underneath cavity floor. To determine the permeability of mercury in the teeth following experiments were performed. Class 5 cavities total 40 from 10 dogs were prepared on upper and lower canines and amalgam alloys which contain about 10uCi of radioactive mercury were inserted. The animals were sacrificed 7 days after the experiments and the teeth were decalcified, sectioned and autoradiographed by means of emulsion and stained by H & E. Following are the results obtained from this experiments. 1. Blackened silver grains were found along the dentinal tubules underneath the cavity floor. Beyond the border of dentine and pulp chamber grains were seen in odontoblastic layer (Fig. 1, 2, 3, 4) 2. Underneath the odontoblastic layer, the pulp tissue showed almost normal appearance except slight dilatation of blood vessel.

• Restorative Dentistry and Endodontics
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• v.23 no.2
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• pp.586-596
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• 1998

Amalgam is one of the most commonly used dental restoration material because of its convenience, economic and physical properties. But microleakage in the tooth and amalgam interface has been its major problem, and many efforts have been made to overcome this shortcoming. The purpose of this study is to compare the effect of various liners on microleakage of amalgam restoration. Cavities were prepared on the buccal or lingual surface of ninety sound, extracted human premolars and six different liners (Tubulitec$^{(R)}$, Superbond D-liner II Plus$^{(R)}$, Superbond D-liner II Plus$^{(R)}$ with polymer, Scotchbond Multipurpose Plus$^{(R)}$, Copalite$^{(R)}$, No liner) were unapplied according to manufacturer's instructions and amalgam had been condensed immediately. The specimens were thermocycled by dipping in methylene blue dye at $5^{\circ}C$ and $55^{\circ}C$ for 1500 cycles. The amalgam-tooth interface was examined under stereobinocular microscope and the dye penetration was scored. The results were as follows : 1. The Tubulitec$^{(R)}$ group showed less microleakage than no liner or Copalite$^{(R)}$ group (p<0.01). 2. The Tubulitec$^{(R)}$, Superbond D-liner II Plus$^{(R)}$, Superbond D-liner II Plus$^{(R)}$ with polymer and Scotch bond Multipurpose Plus$^{(R)}$ groups were not significantly different. 3. The Copalite$^{(R)}$ and Scotchbond Multipurpose Plus$^{(R)}$ groups were not significantly different. Using the polystyrene liner and resin liners under admixed type of high-copper amalgam restoration significantly reduced microleakage in the tooth-amalgam interface. Further clinical studies on polystyrene liner are recommended.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.8 no.1
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• pp.5-9
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• 1978

The purpose of this study is to investigate the effect of dental restorations on the periodontal and periapical tissues. The author examined 620 cases of amalgam, 390 cases of gold inlay, 422 cases of crown and 644 cases of bridge through the standard intraoral films being appended in the charts that had been kept at the Dept. of Oral Diagnosis in Seoul National University Hospital. This study obtained the following results; 1. The restorations of amalgam, gold inlay crown and bridge were found more frequently in female than in male. 2. The restorations of amalgam, gold inlay and crown were found more numerously in mandibular teeth than in maxillary teeth in both sexes. But in the case of crown, the fact is quite the reverse especially in anterior teeth. 3. On the contrary, in the case of bridge, the restorations of bridge were much more distributed in the maxillary teeth than in the mandibular teeth. 4. Roentgenographic changes of periodontal tissues whose teeth were treated with any type of four restorations were periodontal space widening, lamina dura discontinuity and periapical lesion in the order described in both sexes. 5. On the occasion of between amalgam and gold inlay or between crown and bridge, the differences of periodontal changes were of no consequence. On the other hand, the differences of periodontal changes were apparant between the group of amalgam & gold inlay and the group of crown & bridge.

• Journal of Korean society of Dental Hygiene
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• v.6 no.3
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• pp.203-218
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• 2006

The purpose of this study was to measure dental hygienists' perception of the usefulness of clinical practice training. A total of 195 dental hygienists participated in the study. The findings of the study were analyzed according to age, the type of hospitals where respondents were working, experience in clinical practices and educational level as follows: 1. There were statistically significant differences in perception of the usefulness of the practice of amalgam filling preparation performed for dental operation among subjects at different ages (p<.01). 2. There were statistically significant differences in perception of the usefulness of the practice of paralleling technique(p<.001), the practice of amalgam filling preparation(p<.01) and the practice of trauma treatment preparation(p<.05) among subjects working at different clinics 3. Significant differences were observed in perception of the usefulness of the practice of sterilization(p<.05), the practice of suction(p<.05), the practice of history taking preparation (p<.01) and the practice of halitosis patient management preparation(p<.05) among subjects with different years of experience in clinical practices. 4. Significant differences were found in perception of the usefulness of the practice of paralleling technique among subjects with different education levels. The findings of the study suggest the need for strengthening education programs for clinical training content and practices which subjects considered important for their job. At the same time, the study emphasizes the need for developing training programs designed to produce dental hygiene preceptor who can provide dental hygienists with practical clinical training in cooperation with college and dental clinics.

• Imaging Science in Dentistry
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• v.51 no.3
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• pp.261-269
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• 2021

Purpose: The aim of this study was to evaluate the radiopacities of various types of restorative materials with different thicknesses compared with enamel, dentin, and aluminum. Materials and Methods: Four bulk-fill resins, 2 hybrid ceramics, 2 micro-hybrid resin composites, 6 glass ionomer-based materials, 2 zinc phosphate cements, and an amalgam were used in the study. Twelve disk-shaped specimens were prepared from each of 17 restorative materials with thicknesses of 1 mm, 2 mm, and 4 mm (n=4). All the restorative material specimens with the same thickness, an aluminum (Al) step wedge, and enamel and dentin specimens were positioned on a phosphor storage plate and exposed using a dental X-ray unit. The mean gray values were measured on digital images and converted to equivalent Al thicknesses. Statistical analyses were performed using 2-way analysis of variance and the Bonferroni post hoc test(P<0.05). Results: Radiopacity was significantly affected by both the thickness and the material type (P<0.05). GCP Glass Fill had the lowest radiopacity value for samples of 1 mm thickness, while Vita Enamic had the lowest radiopacity value for 2-mm-thick and 4-mm-thick samples. The materials with the highest radiopacity values after the amalgam were zinc phosphate cements. Conclusion: Significant differences were observed in the radiopacities of restorative materials with different thicknesses. Radiopacity was affected by both the material type and thickness.

• Restorative Dentistry and Endodontics
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• v.1 no.1
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• pp.8-10
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• 1975

This study is to determine or detect deposition of mercury particles emitted from dental amalgam fillings. Amalgam fillings were carried out routinely on the dogs' teeth. (CIV cavities) Mercury which contains about 200${\mu}Ci$ of $^{197}Hg$ was employed on this purpose in each cavity. Radioactivity was measured by means of well type scintillation counter from saliva and mucous membrane of surrounding tissue. The C. P. M. value from the saliva was highest, mucous membrane was moderate and least on blood and fecs, as shown table on I. II. III. IV. 1. C.P. Mvalue from Saliva reveals 114 to 135 (lowest and highest) throughout the measuring period until 41 hours. 2. From blood samples no significant value was found. 3. CPM value from feces at2nd day and 4th day was about 90. 4. The highest and lowest CPMvalue from marginal gingiva was 465 and 209 respectively. Palatine showed 281 and 189, esophagus 179 and 165, and pulp from experiment tooth 190 and 104 respectively.

• Journal of the korean academy of Pediatric Dentistry
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• v.7 no.1
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• pp.7-11
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• 1980

6877 children who visited to pedodontic department from 1976 to 1979, were surveyed on the state of dental caries, therapic inclination a year and yearly tendency of treatment. The results were as follows ; 1. The prevalence of dental caries tended to show the increase in general year by year. 2. Girls had higher d.e.f. T. & S. index and D.M.F. T. & S. index than boys generally. 3. Distribution of therapy a year. (1979) Amalgam Filling 4464 Pulpotomy 952 S.P.-Crown 1538 Gold Inlay 250 Space Maintainer 341 Extraction 1313 Orthodontic Appliance 206 4. Tendency of treatment in 1979 (compared with 1976) No. of new patients 87.5% increased Amalgam Filling 50.0% increased Extraction 31.4% increased Orthodontic Appliance 267.9% increased S.P.-Crown 225.8% increased Gold Inlay 27.8% decreased Space Maintainer 2.3% decreased Pulpotomy 20.5% decreased.

• The Journal of the Korean dental association
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• v.12 no.6
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• pp.373-375
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• 1974

This is to determine the possibility of penetration of evaporated mercury to periodontal tissue after amalgam filling. Class 5 cavities on upper canine, total 40 teeth from 10 dogs, were prepared and amalgam alloy which contain about 10 Ci of radioactive mercury were inserted. The animals were sacrificed after the experiment. The teeth were routinely decalcified, sectioned, autoradiographed by means of emulsion and stained by H & E. 1. Blackened grains were found along collagen fiber space underneath gingival sulcus floor. 2. Mercury particle deposited more at cervical portion of periodontium than apical portion. 3. Blackened grains were found along the Sharpey's fiber. Crest bone side was more evident than cement side. 4. Mercury penetration to periodontium of non-experimented tooth showed almost same findings as experimented one.