• 대한치과의사협회지
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• 제23권12호통권199호
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• pp.1031-1037
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• 1985

The purpose of this study was to evaluate the marginal sealing ability of 'vivadent.' Using freshly extracted human teeth and 2% aqueous methylene blue, the marginal leakage of dye in restorative materials such as vivadent with acid etching technique, Durafill with acid etching technique, silar with acid etching technique, Adaptic, and Amalgam were investigated at 37℃ and under temperature cycling in range of 4℃-60℃. The results were as follows; 1. All filling materials showed some degree of marginal penetration by 2% methylene blue dye. 2. Vivadent with acid etching technique revealed effective marginal sealing ability, but under temperature cycling it showed increased marginal leakage. 3. All resins showed greater marginal leakage than amalgam restoration. 4. Vivadent had the most effective marginal sealing ability in experimented resins.

• Restorative Dentistry and Endodontics
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• 제16권1호
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• pp.6-15
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• 1991

The purpose of this study was to observe in vitro chloride corrosion behavior from 5 kinds of amalgam (Caulk spheracal, Amalcap, Dispersalloy, Tytin, Sybralloy) as a function of time after tritruration by using potentiostat. After each amalgam alloy and Hg was triturated as the direction of the manufacturer by the mechanical amalgamator, the triturated mass was inserted the cyrindrical matal mold ($12{\times}10mm$) and was condensed by using routine manner. The specimen was removed from the mold and was stored at room temperature for 1 week, 1 month and 3 months, and standard surface preparation was routine carried out. The 0.9% saline solution was used as electrolyte in pH 6.8~7.0 at $30{\pm}0.5.^{\circ}C$. The open circuit potential was determined after 30 minutes' immersion of 1 week, 1 month and 3 month old specimens. The scan rate was 1 mV/sec and the surface area of amalgam exposed to the solution was $0.65\;Cm^2$ for each specimen. All potentials reported are with respect to a silver / silver chloride electrode (SSE). The following result was obtained. 1. All amalgam specimens became more noble corrosion potentials which represent the improved corrosion resistance as the time elapsed. 2. Three kinds of high copper amalgam always exhibited more noble potential than low copper amalgam at 1 week, 1 month and 3 months. 3. Two kinds of low copper amalgam had the similar polarization curve pattern with 3 current peaks at each time period and current densities associated with these peaks were decreased as aging especially in caulk spherical amalgam. 4. All kinds of high copper amalgam had the similar polarization curve pattern with absence of prominent current peak at each time period, but the polarization curve of D amalgam had one apparent current peak at 1 week.

• Restorative Dentistry and Endodontics
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• 제13권2호
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• pp.221-235
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• 1988

The purpose of this study was to observe characteristic properties through the polarization curves and EMPA images from 4 different types of amalgam obtained by using the potentiostats (EG & G PARC) & EPMA (Jeol JSM-35), to investigate the degree of corrosion of each phase of amalgam on the oxidation peak, and to identify corrosion products from the corroded amalgam by use of X-ray diffractometer(Rigaku). After each amlgam alloy and Hg were triturated as the direction of the manufacturer by means of the mechanical amalgamator(Shofu), the triturated mass was inserted into the cylindrical metal mold which was 12mm in diameter and 10mm in height and was condensed by means of routine manner. The specimen was removed from the mold and stored at room temperature for about 7 days. The standard surface preparation was routinely carried out. Anodic polarization measurement was employed to compare the corrosion behaviours of the amalgams in 0.9% saline solution(pH6.8~7.0) and artificial saliva (pH6.8~7.0) at $37^{\circ}C$. The open circuit potential was determined after 30 minutes' immersion of specimen in electrolyte and the potential scan was begun at the potential of 100mV cathodic from the corrosion potential. The scan rate was 1mV/sec and the surface area of amalgam exposed to the solution was 0.64$cm^2$ for each specimen. All the potentials reported are with respect to a saturated calomel electrode (SCE). EPMA images on the determined oxidation peaks of each amalgam in artificial saliva were observed. X-ray diffraction patterns of each sample were recorded before and after polarization in artificial saliva (Aristaloy, Caulk Spherical, Dispersalloy and Tytin: at +770mV, +585mV, +8.10m V and +680m V respectively) by use of a recording diffractometer. Nickel filtered Cu $K_{{\alpha}_1}$ radiation was used and sample was scanned at $4^{\circ}(2{\theta})/min.$ from $25^{\circ}$ to $80^{\circ}$. The following results were obtained. 1. Oxidation peak potential in artificial saliva shifted to more anodic direction than that in saline solution. 2. The corrosion potential of high copper amalgam was more anodic than the potential of low copper amalgam. 3. The current density was lower in artificial saliva than in saline solution. 4. One of the corrosion products, AgCl was identified by X-ray diffraction analysis. 5. ${\gamma}_2$ phase was the most susceptible to corrosion and e phase was stable in low copper amalgam and ${\eta}$' phase and Ag-Cu eutectic were susceptible to corrosion in high copper amalgam.

• 대한치과마취과학회지
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• 제10권1호
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• pp.54-57
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• 2010

Foreign body aspiration (FBA) into the tracheobronchial tree could be life threatening requiringprompt intervention. Any objects placed in the oral cavity put patients at a risk of aspirating or swallowing the objects slipped or broken by physical injuries. Here, we report a case of 30 yr old patient with FBA during gold crown replacement was successfully treated with the use of the flexible bronchoscope. Case: A 30 yr old woman was admitted to Seoul National Dental Hospitalfor an amalgam restoration. She was scheduled to gold crown restoration for replacement of the damaged amalgam at #37 site. After performing crown lengthening procedure, the aspiration of gold crown occurred during the cementation of the crown. After aspiration, the patients complained of the subjective distress of respiration. Chest radiograph revealed that gold crown was enlodged to the left bronchus. Flexible fiberoptics was inserted to the bronchus to remove the aspirated crown. Fiberoptic assisted removal of the aspiratedcrown was successfully performed. After removal, there was no radiopaque material in the left bronchus on follow-up chest radiograph. Discussion: When aspiration of dental materials occurs, flexible fiberoptic can be used in the treatment of FBA. It is also very useful to take preventive management such as rubber dam, application of dental floss in dental procedure where there is high likelihood of FBA.

• 대한치과의사협회지
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• 제10권8호
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• pp.503-507
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• 1972

Authors had observed the average numbers of the fille teeth per mouth, and the occurrence rates of the secondary caries around the various forms of the filling bodies in 2,093 dental out-patients in the Infirmary, College of Dentistry, Seoul National University in 1970, in order to make a basic data considered in the establishment of the policy for the dental health in Korea. The obtained results were as follows: 1. In Korea, the average number of the filled teeth per mouth in the dental out patients had been increased gradually. 2. In the dental out-patients in 1970, the relative rate of amalgam filling bodies had been decreased, but the relative rate of gold inlays increased compared with the dental out-patients in 1963 and 1964. 3. The secondary caries around the various forms of the filling bodies was 6.38 percent of total caries cavities. 4. 17.14 percent of total filling bodies was accompanied with the secondary caries. 5. The secondary caries had been occurred from the margin in 22.52 percent of amalgam filling bodies, in 8.84 percent of gold inlays, in 18.84 percent of silicate filling bodies, and in 22010 percent of temporary filling bodies.

• The Journal of Advanced Prosthodontics
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• 제3권4호
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• pp.186-189
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• 2011

PURPOSE. Porcelain fused to metal (PFM) crowns provide the best treatment option for teeth that have a large or defective restoration. More than 20% of teeth with PFM crowns or bridges require non-surgical root canal treatment (NSRCT). This may be due to the effect of restorative procedures and the possible leakage of bacteria and or their by-products, which leads to the demise of the tooth pulp. Thus, this study was planned to compare the ability of the restorative materials to seal perforated PFM specimens. MATERIALS AND METHODS. The study evaluates the ability of amalgam, composite or compomer restorative materials to close perforated PFM specimen's in-vitro. Ninety PFM specimens were constructed using Ni-Cr alloys and feldspathic porcelain, and then they were divided into 3 groups: amalgam (A), composite + Exite adhesive bond (B) and compomer + Syntac adhesive bond (C). All the PFM samples were embedded in an acrylic block to provide complete sealing of the hole from the bottom side. After the aging period, each group was further divided into 3 equal subgroups according to the thermocycling period (one week for 70 cycles, one month for 300 cycles and three months for 900 cycles). Each subgroup was put into containers containing dye (Pelikan INK), one maintained at $5^{\circ}C$ and the other at $55^{\circ}C$, each cycle for 30 sec time. The data obtained was analyzed by SPSS, 2006 using one way ANOVA test and student t-test and significant difference level at (P<.01). RESULTS. The depth of dye penetration was measured at the interfaces of PFM and filling materials using Co-ordinate Vernier Microscope. The lowest levels of the dye penetration for the three groups, as well as subgroups were during the first week. The values of dye leakage had significantly increased by time intervals in subgroups A and C. CONCLUSION. It was seen that amalgam showed higher leakage than composite while compomer showed the lowest level of leakage.

• 대한치과의사협회지
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• 제12권8호
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• pp.619-622
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• 1974

The purpose of this study was to investigate biological tissue reactions to various restorative dental materials. An experimental pellects was implanted into subdermal tissue in dog subjects observing 1 week, 3 weeks, and 8 weeks respectively. The obtained histo-pathological findings were as follows: 1. Experimental pellets such as gold, ticonium and amalgam alloy are considered biologically acceptable. 2. Experimental results in 1 week dog showed acute inflammatory changes. 3. Experimental results in 8 week dog showed fibrotic and chronic inflammatory changes. 4. Active irritans such as silicate cements revealed acute inflammatory changes in all observed period. 5. Biological tissue to irritants observed.

• 대한소아치과학회지
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• 제25권2호
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• pp.323-334
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• 1998

The purpose of this study was to compare the microleakage of the amalgam and the gallium alloy when several lining materials were applied. The ANA 2000, high copper lathecut type amalgam(AM group) and Gallium Alloy GF II (GF group) were used. The fifty extracted sound molars were randomly assigned to AM group and GF group, and the buccal and lingual class V cavities with a size $3{\times}2{\times}2mm$ were prepared. The prepared cavities were randomly assigned to group 1 : no liner used control, group 2 : Copalite, group 3 : Panavia 21, group 4 : All-bond 2, and group 5 : Superbond C&B. After liner placement and amalgam filling, the specimens were stored in $37^{\circ}C$ normal saline for 24 hours and then thermocycled from $5^{\circ}C$ to $55^{\circ}C$ thousand times. The specimens were stored in the 1% methylene blue solution for 24 hours and sectioned and examined by stereomicroscope. The results obtained from this study can be summarized as follows : 1. In the GF group, microleakage values of group 2, 3, 4, 5 were significantly lower than that of group 1 (p<0.05). 2. In the AM group, microleakage values of group 3 and 4 were significantly lower than that of group 1 (p<0.05), but microleakage values of group 2 and 5 did not differ from that of group 1 (p>0.05). 3. The GF group was similar(group, 1 3, 4) or superior(group 2, 5) to the AM group in the aspect of the microleakage.

• Restorative Dentistry and Endodontics
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• 제15권1호
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• pp.107-119
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• 1990

The purpose of this study was to evaluate the marginal adaptability of the amalgam restorations in applying the cavity varnish (Copalite$^{(R)}$) and dentin bonding agent (Scotchbond 2$^{(R)}$) under the scanning electron microscope. For this study, eighteen sound extracted human molars were selected. Class I cavities in 12 teeth and class V cavities in 6 teeth were prepared using an air turbine with No. 701 tungsten carbide bur and finished using a low speed handpiece with No. 557 fissure bur. The prepared specimens were then divided into three groups including 4 class I cavities and 2 class V cavities in each group and restored as follows ; Group I. All the prepared cavities were restored with amalgam only (Control). Group II. Two layers of Copalite$^{(R)}$ cavity varnish were applied to the cavities with a gentle stream of air after each application and cavities were restored with amalgam. Group III. The enamel cavity margins were etched with 37% phosphoric acid gel for 60 sec., rinsed for 30 sec. and dried. One layer of visible lightcured Scotchbond Dental Adhesive$^{(R)}$ was applied and immediately cured for 20 seconds with visible light-cure unit and cavities were restored with amalgam. All the specimens were cut at the neck of the teeth and the occlusal halves of specimens were sectioned buccolingually in the longitudinal axis centering the amalgam restorations, using the disk. The cut specimens were ground with sandpapers (400, 600, 800, 1000 grit), and cleaned for 5 minutes in the ultrasonic cleaner (Brason Co. U.S.A.). In the cut surfaces, the amalgam - tooth interfaces were examined under the scanning electron microscope (JSM, 35C type, JEOL). The obtained results were as follows ; 1. The amalgam-tooth interfaces were reduced more significantly in the Copalite$^{(R)}$ and Scotchbond 2$^{(R)}$ application group than in the control group. 2. In the class I cavities, the Scotchbond 2$^{(R)}$ application group showed the findings similar to the Copalite$^{(R)}$ application group in the cavity floor, and the marginal adaptability was better in the side wall than in the cavity floor. 3. In the class I cavities, the Scotchbond 2$^{(R)}$ application group showed better marginal adaptability in the occlusal margin than in the gingival margin. 4. The marginal adaptability was in the order of the Scothbond 2$^{(R)}$ application group, the Copalite$^{(R)}$ application group and the control group.

• 대한치과의사협회지
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• 제54권11호
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• pp.840-849
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• 2016

The purpose of this study was to examine dental care utilization and expenditures among children aged 0 to 19 years using Korea Health Panel Survey (KHPS) data in 2008 - 2013. Weighted estimates were nationally representative and statistical significances were analysed by $x^2$ test or adjusted Wald test using STATA 13 software. While dental care utilization increased steadily among children from 2008 through 2013, less than one-third the children received dental care in 2013. Compared with 2008, the proportion of restorative care, oral surgery, preventive care decreased and the proportion of orthodontic care, prosthetic care increased. While the proportion of amalgam markedly decreased, the proportion of resin increased. This study highlight socioeconomic disparities in dental utilization and expenditures among children. Especially the findings provide a baseline assessment for examining trends on dental care for children in the future.