• Restorative Dentistry and Endodontics
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• 제12권2호
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• pp.55-63
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• 1987

The purpose of this study is to evaluate the effect of dentin bonding agents on marginal leakage. V-shaped cavities were prepared on the faciocervical area of 140 extracted human teeth. In Groups of twenty cavities, they were restored as follow: Group 1 with enamel bonding resin and Silux, Group 2 Scotchbond and Silux, Group 3 enamel bonding resin and Heliomolar, Group 4 Dentin Adhesit and Heliomolar, Group 5 enamel bonding resin and Durafill, Group 6 Dentin Adhesive and Durafill, Group 7 Chembond. All specimens were thermocycled alternatively at $4^{\circ}C$ and $60^{\circ}C$ of 2% methylene blue dye solution, and sectioned faciolingually with diamond disk under water spray. The sectioned specimens observed with stereo microscope. Following results were obtained: 1. The groups filled with Scotchbond-Silux or Dentin Adhesit-Heliomolar had appeared lesser marginal leakage compared with the groups with enamel bonding resin-Silux or enamel bonding resin-Helimolar. 2. The group filled with Dentin Adhesive-Durafill did not show the reduction of the marginal leakage compared with the group with enamel bonding resin-Durafill. 3. There was significant difference among the four dentin bonding agents. Scotchbond showed the greatest marginal sealing ability, and Dentin Adhesit was the next. The marginal sealing ability of Dentin Adhesive was the worst.

• Restorative Dentistry and Endodontics
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• 제7권1호
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• pp.77-83
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• 1981

The purpose of this study was to observe the bonding strength between tooth surface (enamel and dentin) and restorative filling materials which are two composite resins (Clearfil and Concise) and Glass ionomer cement, after etching with 50% phoshoric acid and 37% citric acid. To measure the bonding strength in enamel, the labial surface of upper anterior tooth was cut flatly with using carborundum disk and polished with sand paper disk, and to measure in dentin, the dentin surface was prepared by grinding upper part of posterior tooth horizontally. After washing the tooth surface with water and drying with air blast, the prepared tooth surface was etched. In glass ionomer cement, 50% phosphoric acid and 37% citric acid were used, in Clearfil 40% phosphoric acid was used and in Concise, 50% phosphoric acid and 37% citric acid were used as etchant for 1 minute. After the copper band which is 5 mm in diameter and 5 mm in height was fixed on the prepared surface and each filling material was inserted into the copper band, the hooking loop was inserted into filled material in the copper band before setting to make it easily that the load is applied on the specimen. After all specimens were immersed in water at $37^{\circ}C$ for 1 week, this specimen was placed on the load cell of tensile test apparatus, and specimen was pulled at the cross-head speed of 0.8 mm per minute. The following results were obtained 1) In glass ionomer cement, the bond strength obtained by 37% citric acid was higher than one obtained by 50% phosphoric acid in enamel and dentin surfaces. The bond strength obtained in non-etched surface was much less than one by etchants in enamel and dentin surface. 2) In Clearfil, the bond strength obtained by 40% phosphoric acid was 4 times more than one obtained by non etch ant. 3) In Concise, the bond strength obtained by 50% phosphoric acid was almost same as one obtained by 37% citric acid, and the bond strength obtained by non etch ant was much less than one obtained by etchants.

• 대한소아치과학회지
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• 제25권4호
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• pp.749-760
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• 1998

The main purpose of this study was to evaluate the effect of dentin with various pretreatment application time on the dentin surface structure and the bond strength of glass ionomer restorative matrials between primary and permanent tooth. There are difference of composition, structure and pretreated effect of dentin conditioning between the primary and permanent teeth. Inspite of thease fact, we used the same application time of permanent tooth. This study intends to determine the most effective application time using SEM analysis of the surface change by dentin conditioning. Forty five intact primary and permanent teeth were splited mesiodistally with seperating diamond disk. Each eight specimens were prepared for shear bond strength test. (randomely devided eight group as follows:) group I conditioning for five seconds group II conditioning for ten seconds group III conditioning for fifteen seconds group IV conditioning for twenty seconds Additional specimens were prepared to SEM analysis. The result are as follows: 1. Primary teeth are higher shear bond strength in group I and group II. 2. There was no statistically significant difference between primary and permanent teeth in group III and group IV. 3. In SEM analysis, smear layer removal by dentin pretreatment of primary teeth was faster than permanent teeth. Primary teeth may require shorter pretreatment time of dentin for G-I restoration than that of permanent teeth.

• 대한소아치과학회지
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• 제30권4호
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• pp.545-553
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• 2003

상아질 접착력을 높이기 위해서는 적절히 습윤한 상아질 표면을 얻는 것이 중요하다. 이런 방법에는 정확한 지침이 없으며, 주관적이고 술자에 따라 많은 차이가 있다. 본 연구에서는 적절히 습윤한 상아질을 얻는 방법에 관한 연구의 일환으로, 유치의 산부식 후. 여러 가지 방법을 이용해 상아질을 건조시킨 표본의 조직상을 획득하여 상아질 표면의 차이를 비교하고자 하여 다음과 같은 결론을 얻었다. 1. 유치 상아질을 산부식하면, 도말층이 제거되고 상아세관이 노출되며, 관간상아질과 관주상아질이 탈회되고, 교원섬유가 풍부한 이행층이 노출되는 것을 확인할 수 있었다. 2. 산부식된 상아질이 과도하게 건조되면 탈회된 상아질이 수축하여, 관간상아질이 붕괴되어 높이가 점차적으로 낮아지고 상아세관의 직경은 조금씩 감소되는 것으로 나타났다. 3. 유치 산부식 후, 10cm 거리에서 20초 동안 압축 공기로 건조시키면 상아질이 과도하게 건조, 탈수됨을 확인할 수 있었다. 4. 유치 산부식 후, 10cm 거리에서 3초 동안 압축 공기로 건조시키거나 마른 cotton, 젖은 cotton, microbrush, absorbent tissue paper로 건조시키면 상아질이 적절하게 건조됨을 확인할 수 있었다.

• 대한치과보철학회지
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• 제30권1호
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• pp.103-124
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• 1992

The purpose of this study was to investigate the effect on the fracture strength and color of ceramic by the design of the metal coping in ceramo metal crown. In this study, four types of ceramic crowns were made for fracture strength : standard ceramo metal crown, collariess ceramo metal crown, modified ceramo metal crown, and ceramic jacket crown. And three types of disk formed-specimens were made to compare the dentin shade owing to aluminous opaque powder and palladium alloy. Fracture strength was measured by universal testing machine(Instron Co. Ltd., U.S.A) and color was measured by color and color difference meter(Yasuda Seiki Seisakusho, Ltd., Japan). The results were as follows : 1. The fracture strength of ceramic was affected significantly by the design of metal coping in ceramo metal crown. The mean fracture strength(192.0 Kg) of standard ceramo metal crown was about 1.7 times higher than that(111.5 Kg) of collarless ceramo metal crown, and about 2.8 times higher than that(67.8 Kg) of ceramic jacket crown. 2. Modified ceramo metal crown that has metal band in the labio cervical had the lowest fracture strength. 3. Lightness, yellowness and redness of the dentin fired were decreased by the metal coping.

• Imaging Science in Dentistry
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• 제51권3호
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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.

• 대한소아치과학회지
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• 제51권1호
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• pp.32-39
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• 2024

This study evaluated the additive impact of ethylenediamine tetraacetic acid (EDTA) on erythrosine-mediated photodynamic therapy (PDT) against Streptococcus mutans (S. mutans) biofilm by measuring colony-forming units and applying confocal laser scanning microscopy. Fifty-six bovine incisors, free from dental caries or structural defects, were utilized in this study. Dentin specimens were created by cutting with a low-speed diamond disk under a continuous flow of water, resulting in dimensions of 6.0 mm × 3.0 mm × 2.0 mm. The specimens were categorized into 4 groups: Control, EDTA, PDT, and EDTA + PDT. S. mutans ATCC 25175 was employed to establish biofilm on the dentin specimens. A 17% EDTA solution was applied for 1 min. For PDT, erythrosine served as the photosensitizer. Finally, a light-emitting diode source (385 - 515 nm) was employed in this study. The PDT group exhibited a significantly lower bacterial count than both the control and EDTA groups (p < 0.001). The EDTA + PDT group demonstrated a significantly reduced bacterial count compared to the other 3 groups (p < 0.001). This study demonstrated that EDTA enhances the antimicrobial efficacy of PDT on S. mutans biofilm. Even at a low concentration of photosensitizer, the combination of EDTA and PDT yields a significant antibacterial effect.

• 대한소아치과학회지
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• 제25권1호
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• pp.234-248
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• 1998

The purpose of this study was to compare the fracture and shear bonding strength of resin-modified glass ionomer cements with composite resin and conventional glass ionomer cement Three kinds of restorative materials including a composite resin (Z 100), a conventional glass ionomer cement(Fuji II), and resin- modified glass ionomer cements(Fuji II LC, Vitremer, Dyract and Compoglass) were investigated in this study. For measurement of fracture and shear bonding strength, disk samples of the materials were prepared and cylindrical samples of the materials were bonded the flat enamel and dentin surfaces according to manufactuer's instructions. All specimen were determinated by using an Instron testing machine with a crosshead speed of 1 mm/min. Then, each treated enamel and dentin surface was observed by SEM. The following results were obtained. 1. The bi-axial flexural strength of Z 100 was highest, and Fuji n LC, Vitremer, Dyract and Compoglass were significantly higher than Fuji n (P<0.05). 2. The shear bonding strength of Z 100 on the enamel and dentin surface was higher than other experimental groups except Fuji II LC(P<0.05). Fuji II LC was significantly higher than Fuji II (P<0.05), but in the case of Vitremer, Dyract and Compoglass were similar to Fuji II (P>0.05). 3. The shear bonding strength of Z 100 and Fuji II LC on the enamel surface were highly increased as compared with dentin surface (P<0.05), but in the case of Fuji II, Vitremer, Dyract and Compoglass were not different between enamel and dentin(P>0.05). 4. In the Z 100 and Fuji II LC, obvious etched enamel surface and exposed dentinal tubules according to remove of smear layer and smear plug were observed.

• Restorative Dentistry and Endodontics
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• 제10권1호
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• pp.135-144
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• 1984

This study was undertaken to evaluate the degree of the marginal leakage of composite restoration with 3 brands of dental adhesives by means of the dye penetration at the enamel and dentinal margins. 150 cavities of class V were prepared on the buccal and lingual surfaces of 75 extracted anterior and premolar teeth, which were devided into 3 groups. The cavities were filled with composite resin, Silar$^{(R)}$ (3M) and Heliosit$^{(R)}$ (Vivadent) after application of the dental adhesives, specifically Scotchbond$^{(R)}$ (3M) which is essentially composed with halophosphorus ester of Bis-GMA, Dentin Adhesit$^{(R)}$ (Vivadent) which is polyurethane resin, and Enamel Bond$^{(R)}$ (3M) which is a product of Bis-GMA with low viscosity at internal surfaces and margins of the cavities. All specimens were immersed in $37^{\circ}C$, 0.5% methylene blue solution for 24 hours after thermocycling at $4^{\circ}C$ and $60^{\circ}C$, embedded in acrylic resin, and sectioned with diamond disk into two parts. The sectioned specimens observed with the light microscope. The following results were obtained: 1. The group filled with Scotchbond$^{(R)}$-Silar$^{(R)}$ the other two groups at the enamel margins. 2. No significant difference in the degree of the marginal leakage had appeared between Dentin Adhesit$^{(R)}$-Heliosit$^{(R)}$ group an d Enamel Bond$^{(R)}$-Silar$^{(R)}$ group at the enamel margins. 3. Severe marginal leakage with penetration of dye to the floor of cavity had appeared from the all three groups and no significant difference in the degree of marginal leakage existed between the three groups at the dentinal margins.

• 대한치과보철학회지
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• 제38권2호
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• pp.255-263
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• 2000

The purpose of this study was to compare the microleakage of the composite resin cores according to surface treatment, dentin bonding agents, and thermocycling. For this study, 120 extracted premolar teeth were used. Flat occlusal surfaces were prepared with diamond disk, and treated with air-abrasion, acid-etching, combination. The composite resin core was built with Z-100 after application of Scotchbond Multi-Purpose and All-Bond 2. Prepared specimens were thermocycled for 2,000 cycles. Specimens were immersed in 1% methylene blue solution for 24hours at $37^{\circ}C$. The microleakage was measured with a inverted metallurgical microscope(BHS313, Olympus, Japan). The following conclusions were drawn from this study: 1. The microleakages in the groups treated with air-abrasion and with acid etching were greater than that of the groups treated with combination method before thermocycling(p<0.05), the microleakages of the groups treated with air-abrasion were greater than that of the groups treated with acid-etching and combination method after thermocycling(p<0.05) 2. There were no significant difference between groups using Scotchbond Multi-Purpose and the groups using All-Bond 2. 3. Thermocycling didn't affect the change of microleakage in all cases.