• Restorative Dentistry and Endodontics
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• v.15 no.1
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• pp.120-128
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• 1990

The purpose of this study was to examine the effect of surface treatment on the flexural strength of glass ionomer cement with time elapsed. Glass ionomer cement (Fuji ionomer type II, (GC Co.) was used as experimental materials. Glass ionomer cement was placed in a beam-shaped teflon mold (3mm ${\times}$ 3mm ${\times}$ 25mm) that was rest on a glass plate. Another flat glass was placed on the top of the mold with pressure. After the cement was set, the specimens were divided into three groups and thirty two specimens in each group were surface-treated as follows: No treatment group: Specimens were no surface-treated and stored at $35.6^{\circ}C$ in distilled water. Fuji varnish application (FA) group: Specimens were surface-treated with Fuji varnish (GC Co.) and stored at $35.6^{\circ}C$ in distilled water. Vaseline storage (VS) group: Specimens were no surface-treated and stored at $35.6^{\circ}C$ in vaseline. The flexural strength was measured after I day, 1 week, 2 weeks, 4 weeks from the start of mixing using Instron Universal Testing Instruments. Results were as follows: 1. After 4 weeks, vaseline storage group exhibited the maximum flexural strength (p <0.0005). 2. The flexural strengths in no treatment group were slightly increased with time elapsed, but its difference was not significant, statistically. 3. The flexural strengths in Fuji varnish application group were increased with time elapsed (p <0.05). 4. The flexural strengths in Fuji varnish application group and vaseline storage group were greater than that in no treatment group (p <0.0005).

• Proceedings of the KACD Conference
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• 2003.11a
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• pp.570-571
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• 2003

This study was done to evaluate the shear bond strength between light-cured glass ionomer cement base and resin cement for luting indirect resin inlay and to observe bonding aspects which is produced at the interface between them by SEM(Scanning Electron Microscope). 1)Shear bond strength. Light-cured glass ionomer cement base were made in plastic molds(10mm diameter, 5mm thickness). Two type of light cured glass-ionomer cement were uesd.(중략)

• The Journal of Korean Academy of Prosthodontics
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• v.25 no.1
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• pp.227-242
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• 1987

This study was designed to investigate the pulpal effects of the glass ionomer cement. (Lining cement, G-C Co. Japan) For this purpose, 10 cats were selected, and Class V cavities were prepared on canines of the cats. One experimental group was filled with glass ionomer cement and the other group was filled with zinc phosphate cement . (G-C Co, Japan) The animals of the experimental and control group were sacrificed at 1,2,3,4,6, weeks after the experiment. For comparison of reparative dentin formation pattern in direction of the pulpal and fractured lateral surface, each of them was observed with scanning electron microscope. The findings led to the following conclusions; 1. Reparative dentin of the glass ionomer cement and zinc phosphate cement filling groups were formed on the internal surface of dentin as the shape of hemispherical and spherical with a rough surface. 2. Some of reparative dentin of the glass ionomer cement filling group was started to form at 1 week after experiment, and at 6 weeks after experiment, it had been increased gradually in number and size. 3. Reparative dentin of zinc phosphate cement filling group was formed vigorously, however, gradually was decreased in number and size, and disappeared at 6 weeks after experiment. 4. During the formation of reparative dentin, peritubular dentins were indistinguishable. 5. The diameter of dentinal tubules of reparative dentin has been decreased, during the reparative dentin formed, and it became very irregularly at 6 weeks after experiment.

• Restorative Dentistry and Endodontics
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• v.20 no.1
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• pp.129-141
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• 1995

Composite resin and glass-ionomer cement can be used for the purpose of repair of defective amalgam restoration. The purpose of this study was to evaluate of shear bond strength of esthetic restorative materials to dental amalgam. The materials used in this study were Photo Clearfil Bright(light curing composite resin), Clearfil F II(chemical curing composite resin), Fuji II LC(light curing glass-ionomer cement), Fuji II (chemical curing glass-ionomer cement), All-Bond 2(intermediary), and Scotchbond Multi-Purpose (intermediary). A total of 120 acrylic cylinders with amalgam were divided into 8 groups After amalgam condensation, all specimens were stored for 48 hours in water at $37^{\circ}C$ and tested with Instron universal testing machine between amalgam and composite resins and glass-ionomer cements. The data were analyzes statiscally by ANOVA and Duncan test. The following results obtained ; 1. The shear bond strength of bonded composite resin to amalgam was higher than bonded glass-ionomer cement(P<.001). 2. The group 4 had highest shear bond strength with 15.45kgf/$cm^2$ and the group 5 had lowest shear bond strenght with 3.26kgf/$cm^2$(P<.001). 3. In the group 3, 4, 5, 6, the group 3, 4 with All-Bond 2 had higher shear bond strength than the group 5, 6 with Scotch bond MP both in light-curing and in chemical curing. 4. Both in composite resin and glass-ionomer cement, chemical curing materials had higher shear bond stength than light curing materials(P<.001).

• Restorative Dentistry and Endodontics
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• v.15 no.2
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• pp.1-16
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• 1990

This study was to evaluate the cytotoxic effect in vitro and the tissue response within the rat peritoneal cavity to high copper amalgam and glass ionomer-silver cement, suggested for use as a retrograde endodontic filling material. In the cytotoxicity experiment, the radioactively ($^{51}Cr$) labeled L929 mouse fibroblasts were employed to determine the relative cytotoxicity of two experimental materials. Those materials were evaluated immediately after set and after one and seven days setting. In the tissue response experiment, two experimental materials were to evaluate mean peritoneal cellular count, differential cell count and the content of silver and copper in pooled packed cells and eluate samples taken by peritoneal lavage technique, and compared with surgical control after one day. two, four and six weeks of implantation. The results were as following: 1. High copper amalgam exhibited significant cytotoxicity immediately after set but showed no sign of toxicity after one day and seven days setting materials. 2. Glass ionomer-silver cement showed no sign of toxicity immediately after set and after one day and seven days setting. 3. High copper amalgam and glass ionomer-silver cement groups produce no significant difference in the mean peritoneal cell count when compared with the surgical control group after one day, two and four weeks of implantation. Surgical control group exhibited significantly a greater cell count when compared with the High copper amalgam group after six weeks. 4. High copper amalgam group increased significantly in the percentage macrophages after four and six weeks of implantation when compared with surgical control group. 5. The trace metal analysis involved an increased silver content in the elutes and an increased copper content in the packed cells of high copper amalgam group, and an increased silver content in the packed cells and elutes of glass ionomer-silver cement group.

• Restorative Dentistry and Endodontics
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• v.14 no.2
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• pp.5-19
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• 1989

The purpose of this study was to observe the microleakage of composite resin filling using several glass ionomer cements. The Class V cavities of eighty noncarious human molars were prepared at the cementoenamel juction on the facial and lingual surfaces of each tooth with a No.330 carbide bur in a high speed handpiece. The cavity dimensions were $3.0{\pm}0.5mm$ wide, $2.0{\pm}0.5mm$ high, and $1.5{\pm}0.5mm$ deep and all enamel cavosurface margins were beveled with a No.558 carbide bur in low speed handpiece. The bevel was approximately $45^{\circ}$ and 0.5-1.0mm in width. A total of the 160 cavities was divided into four groups, and then 144 cavities among them were three experimental groups and remaining sixteen cavities were control group. All of the prepared cavities were restored as follows: group 1 : Preparations were restored with there three glass ionomer cements. group 2 : Preparations were restored with a composite resin with three glass ionomer cement bases placed $0.2{\pm}0.1mm$ short of the cavosurface margin. group 3 : Preparations were restored with a composite resin with three glass ionomer cement bases extened to the cavosurface margin. group 4 : As control group, preparations were restored with a composite resin, PALFIQUE. The specimens were then thermocycled in a range of $6^{\circ}C-60^{\circ}C$ and immersed in a bath of 2.0% aqueous basic fuchsin solution for 24 hours. Dye penetration was read on a scale of 0 to 4 by Tani and Buonocore's method. The following conclusions were derived from the results obtained; 1. All groups showed significantly more leakage at the gingival margins than at the occlusal margins(p<0.0005). 2. At the gingival margins, group 1 showed less leakage than group 3(p<0.01) and group 4(p<0.0005), while group 3 exhibited less leakage than group 2(p<0.01) and group 4(p<0.0005). 3. At the occlusal margins, group 4 showed less leakage than group 3(p<0.1) and group 1(p<0.005), while group 3 exhibited less leakage than group 2(p>0.1) and group 1(p<0.025).

• The Journal of Advanced Prosthodontics
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• v.4 no.3
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• pp.127-133
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• 2012

PURPOSE. Many dentists use desensitizing agents to prevent hypersensitivity. This study compared and evaluated the effect of two desensitizing agents on the retention of cast crowns when cemented with various luting agents. MATERIALS AND METHODS. Ninety freshly extracted human molars were prepared with flat occlusal surface, 6 degree taper and approximately 4 mm axial length. The prepared specimens were divided into 3 groups and each group is further divided into 3 subgroups. Desensitizing agents used were GC Tooth Mousse and $GLUMA^{(R)}$ desensitizer. Cementing agents used were zinc phosphate, glass ionomer and resin modified glass ionomer cement. Individual crowns with loop were made from base metal alloy. Desensitizing agents were applied before cementation of crowns except for control group. Under tensional force the crowns were removed using an automated universal testing machine. Statistical analysis included one-way ANOVA followed by Turkey-Kramer post hoc test at a preset alpha of 0.05. RESULTS. Resin modified glass ionomer cement exhibited the highest retentive strength and all dentin treatments resulted in significantly different retentive values (In Kg.): GLUMA ($49.02{\pm}3.32$) > Control ($48.61{\pm}3.54$) > Tooth mousse ($48.34{\pm}2.94$). Retentive strength for glass ionomer cement were GLUMA ($41.14{\pm}2.42$) > Tooth mousse ($40.32{\pm}3.89$) > Control ($39.09{\pm}2.80$). For zinc phosphate cement the retentive strength were lowest GLUMA ($27.92{\pm}3.20$) > Control ($27.69{\pm}3.39$) > Tooth mousse ($25.27{\pm}4.60$). CONCLUSION. The use of $GLUMA^{(R)}$ desensitizer has no effect on crown retention. GC Tooth Mousse does not affect the retentive ability of glass ionomer and resin modified glass ionomer cement, but it decreases the retentive ability of zinc phosphate cement.

• The korean journal of orthodontics
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• v.28 no.5 s.70
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• pp.689-698
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• 1998

The purpose of this study was to evaluate the shear bond strength of light cured glass ionomer cement to enamel surface which treated with $37\%$ phosphoric acid, $10\%$ polyacrylic acid, $1.23\%$ acidulated phosphate fluoride gel and no etching agent. To compare the shear bond strength of glass ionomer cement, light-cured composite resin and chemically-cured composite resin were empoloyed as controls. Eight experiments groups were composed. 10 specimens of each group were bonded by metal bracket by tested in universal testing machine for shear bond strength, in stereoscope for adhesive remnants index. The data were evaluated statistically by SPSS/PC+. The results were as follows. 1. Among the groups of $37\%$ phosphoric acid treated and dry and bonded with light cured glass ionomer, light cured composite resin, and chemically cured composite resin, the shear bond strength of glass ionomer group showed no significant difference to the others, but the shear bond strength of chemically cured resin showed statistically lower than that of light cured resin (p<0.05). 2. The shear bond strengths of glass ionomer cement to enamel treated group with $1.23\%$ acidulated phosphate fluoride gel and $10\%$ polyacrylic acid and $37\%$ phosphoric acid showed statistically higher than that of no etched enamel group(p<0.U). 3. In the groups of glass ionomer cement, the presence of moisture was not significantly effect to the shear bond strength (p<0.05). 4. After debonding, no etched enamel group showed less residual materials on the enamel surface than the group of enamel etched with $37\%$ Phosphoric acid.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.3
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• pp.469-481
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• 2006

Among the etiologic factors of enamel corrosion, daily intake has been considered with a profound interest, especially the intake of acidic drinks. It is thought that the rapid consumption of acidic drinks will not only results in the affection to the teeth but also to the surface of the tooth-colored restorative materials. Therefore, the puopose of this study is to examine the alterations occurred in the surface of the tooth-colored materials according to the exposed time, with 3 most common acidic drinks in contact with daily life. Resin-modified glass-ionomer, polyacid-modified composite resin, composite resin were immersed on 0.9% NaCl, Coke, orange juice, sports beverages as 4 groups in each. The surface hardness and the surface roughness of specimens were measured with following methods: before immersion, 1 day after immersion, 1-,2-,3-,4- weeks after immersion. Results were as follows. 1. Tooth-colored restorative materials, with the exception of composite resin, showed statistically significant changes in surface hardness and roughness when immersed on acidic drinks(p<0.05). 2. The degree of change in surface hardness and roughness occurred as follows, in order of severity from greatest to least resin-modified glass-ionomer, polyacid-modified composite resin, composite resin 3. Sports beverages resulted in greater alterations to surfaces than Coke and orange juice. 4. In the SEM image of the groups immersed in acidic drinks, resin-modified glass-ionomer and polyacid-modified composite resin showed loss of filer. Severe cracks were observed, especially on the resin-modified glass-ionomer.

• Restorative Dentistry and Endodontics
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• v.22 no.2
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• pp.505-518
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• 1997

The objective of this investigation was to compare the effects of water storage on the aspect of hardness and diametral tensile strengths of four hybrid glass ionomer cements(two compomers and two resin-reinforced glass ionomers) with a resin composite material. One composite resin(Degufill Ultra), two compomers(Dyract, Compoglass Cavifil), and two resin-reinforced glass ionomers(Fuji Duet, Vitremer) were used in this study. Cylindrical specimens were prepared and stored at $36{\pm}1^{\circ}C$ in distilled water for 10 minutes after set, and then tested on an Instron testing machine(No.4467) at 1.0 mm/min displacement rate. Vicker's hardness and diametral tensile strengths as time elapsed were measured after aging in water for 10 minutes, 1 hour, 3 hours, 1 day, 3 days, 5 days and 7 days at $36{\pm}1^{\circ}C$. During the test of diametral tensile strength, stress-strain curves were obtained, from which the compressive modulus were calculated and compared. The structure of four set glass ionomer cement mass was observed on SEM(Hitachi, S-2300) after being etched with 9.6% hydrofluoric acid for 1 minute. The results were as follows; 1. The hardness of the experimental group(compomer and the resin reinforced glass ionomer cement) did not exceed the value of control group(Degufill Ultra). 2. Vicker's hardness of the Fuji Duet tended to increase succeedingly, Dyract was decreased after 3 hours in water, and Vitremer was the lowest. 3. The control group(Degufill Ultra) presented progressively on increased diametral tensile strength with time, Fuji Duet were decreased after 3 days, Compoglass Cavifil and Vitremer were decreased after 5 days in water storage. 4. Compressive modulus of the control group(Degufill Ultra) and Dyract were increased sharply timely, Fuji Duet and Vitremer were increased smoothly by lapse of time in water. Fuji Duet were stronger than Vitremer. On the other hand, Vitremer exhibited the lowest toughness. 5. The microstructure of compomer was similar with that of the composite resin(Degufill Ultra), and the fillers in resin-reinforced glass ionomer cements were noticed. It can be concluded that mechanical properties of hybrid glass ionomer cements is weaker than composite resin, and that the compomers or the resin-reinforced glass ionomers can not substitute the composite resins. A plenty of considerations should be done on the application of them to the area under the loading and high wear has a little adverse effect on the mechanical properties on the water storage for 7 days. The further research should be needed to confirm the advantage of the compomer.