• The korean journal of orthodontics
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• v.34 no.4 s.105
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• pp.351-362
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• 2004

Orthodontic band cements are widely used in the fields of orthodontics, but they are commonly known as cytotoxic material. Within an oral cavity several ions and components are released from orthodontic band cements, thus causing inflammation or injury to the Periodontal tissue. Therefore, it is very important to estimate the biocompatibility of orthodontic band cements. The purpose of this study was to assess the cytotoxic effect of orthodontic band cements to HGF cells. A zinc phosphate cement, a glass ionomer, a resin modified glass ionomer, and compomer were used to evaluate three cytotoxicity assays: cell proliferation assay, MTT assay, and agar ovelay assay The results were as follows: 1. In the cell proliferation assay, Gl>ZPC, RMGI, RMGI24, GI24>compomer24, ZPC24, compomer>metal ring lined up in order of cytotoxicity 2. In the MTT assay, GI>ZPC, RMGI>GI24>ZPC24, compomer, metal ring, RMGI24, compomer24 lined up in order of cytotoxicity. 3. In the agar overlay test, GI>GI24, ZPC, ZPC24, RMGI>RMGI24, compomer, compomer24, metal ring lined up in order of cytotoxicity.

• Restorative Dentistry and Endodontics
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• v.25 no.1
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• pp.41-45
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• 2000

The purpose of this study was to evaluate the microleakage of compomers. In this in vitro study, class V cavities were prepared on buccal and lingual surfaces of thirty extracted human premolars and molars on cementum cervical margin. The experimental teeth were randomly divided into five groups of six samples (12 surfaces) each, Group 1 : Dyract AP, Group 2 : F2000 compomer(non-etch), Group 3 : F2000 compomer(etch), Group 4 : Elan, Group 5 : Compoglass. The bonding agents and compomer were applied for each group following the manufacturer's instructions. After 500 thermocycling between $5^{\circ}C$ and $55^{\circ}C$, the 30 teeth were placed 1% methylene blue dye for 24 hours then rinsed with tab water. The specimens were embedded in clear resin, then sectioned buccolingually through the center of the restoration with a low speed diamond saw. The dye penetration on each of the specimen was observed with a stereomicroscope. The results of study were statistically analyzed using the Student-Newmann-Kaul' s Test. The results were obtained as follows. 1. All compomer restoration systems did not completely prevent marginal leakage. 2. In enamel margin, F2000 compomer(etch) group showed lower leakage value than other systems. Elan and Compoglass groups showed lower leakage value than Dyract AP and F2000 compomer(non-etch) groups (p<0.05). 3. In cementum margin, F2000 compomer(etch) and F2000 compomer (non-etch) groups showed lower leakage value than other systems. Dyract AP and Elan groups showed lower leakage value than Compoglass group (p<0.05).

• Journal of Periodontal and Implant Science
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• v.33 no.4
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• pp.705-715
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• 2003

Procedures for treatment of molar furcation invasion defects range from open flap debridement, apically repositioned flap surgery, hemisection, tunneling or extraction, to regenerative therapies using bone grafting or guided tissue regenerative therapy, or a combination of both. Several clinical evaluations using regenerative techniques have reported the potential for osseous repair of treated furcation invasions. Regenerative treatment of maxillary molars are more difficult due to the multiple root anatomy and multiple furcation entrances therefore, purpose of this study was to evaluated histologically compomer and Ketac Silver as a barrier in the treatment of a bi-furcated maxillary premolar. Five adult beagle dogs were used in this experiment. With intrasulcular and crestal incision, mucoperiostcal flap was elevated. Following decortication with 1/2 high speed round bur, furcation defect was made on maxillary premolar. 2 month later one premolar was filled with compomer and the other premolar was filled with Ketac Silver. After 4, 8 weeks, the animals were sacrificed by vascular perfusion. Tissue block was excised including the tooth and prepared for light microscope with H-E staining. Results were as follows. 1. Compomer & Ketac Silver restoration were encapsulated fine connective tissue. 2. In 4 weeks, compomer & Ketac Silver restoration slightly infiltrated inflammatory cells but not disturb the new bone or new cementum formation. 3. In 8 weeks, compomer & Ketac Silver restoration were less infiltrated iflammatory cell and encapsulated fine connective tissue. 4. Therefore, compomer & Ketac Silver filling to the grade III maxillary furcations with multiple root anatomy and multiple furcation entrances is possible clinical method and this technique is useful method for maxillary furcation involvement but it is thought that periodic maintenance should be needed

• Restorative Dentistry and Endodontics
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• v.25 no.4
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• pp.575-586
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• 2000

In this study, adaptation of compomer to saliva contaminated dentin was evaluated with scanning electron microscope(SEM) and confocal laser scanning microscope(CLSM). For the SEM study, the occulusal surfaces of thirty two molar teeth were grounded to exposure dentin surfaces. The specimen were randomly assigned to control and three experimental groups with four samples in each group. In control group, Dyract and F-2000 compomer were bonded on the specimens according to the manufactures direction. Experimental groups were subdivided into three groups. They were contaminated with saliva on dentin surfaces ; Experimental group 1 : Saliva was dried with compressed air. Experimental group 2 : Saliva was rinsed with air-water spray and dried. Experimental group 3 : After polymerization of an adhesive, they were contaminated with saliva, and then saliva was rinsed with air-water spray and dried. Dyract and F-2000 compomer were bonded on saliva-treated dentin surfaces. The interfaces between dentin and compomer were observed with SEM. For the CLSM study, Class V cavities were prepared in buccal and ligual surfacess of thirty two molars. The specimens were divided into control and experimental groups. Class V cavities in experimental group were contaminated with saliva and those surfaces in each experimental groups received the same treatments as for the SEM study. Cavities were applied Prime & Bond 2.1 and F-2000 compomer primer/adhesive that were mixed with fluorescein, and then were filled with Dyract and F-2000 compomer. Specimens were embedded in transparent acrylic resin and sectioned buccolingual1y with diamond wheel saw, and then mounted on cover slide for CLSM study. The interface between cavity and compomer was observed by fluoresence imaging with a CLSM. The results were as follows : 1. In SEM exammination of Dyract group, control group, experimental group 2, 3 showed close adaptation to dentin and hybrid layer of $3{\sim}4{\mu}m$ diameter. Interfacial gap between compomer and dentin in experimental group 1 was wider than in control group. 2. In SEM examination of F-2000 group, adaptation to dentin of control group was closer than Dytact control group, but hybrid-like layer was not observed. Interfacial gap between compomer and dentin in experimental group 1 was wider than in Dyract experimental group 1. 3. In dissolution specimens of Dyract and F-2000 group, resin tags penetrated through dentinal tubules in control group and experimental group 1 and 3, but the penetration of resin tag was irregular and partial in experimental group 1. 4. In CLSM exammination of Dyract and F-2000 group, adhesive patterns of control and experimental groups showed same as in SEM. This result suggests the treatment methods, rinsing & drying, repeating all adhesive procedures, will produce good effect on adaptation of compomer to dentin if the dentin surface or polymerized adhesive is contaminated by saliva.

• Restorative Dentistry and Endodontics
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• v.24 no.2
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• pp.346-355
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• 1999

To evaluate the micro leakage of compomer, 4 materials were divided into 4 groups of 15 cavities each.(Group 1: Z-100, Group 2: Dyarct AP, Group 3: Fuji II LC, Group 4: Compoglass) After the class II cavities were prepared using carbide bur No. 553, all specimen were restored by incremental filling technique. In group 3, Z-100 was filled with a base of a light curing glass-ionomer. After 7 days, all specimens were thermocycled between $5^{\circ}C$ and $55^{\circ}C$ for 500 cycles, followed by placement in 50% silver nitrate dye for 2 hours at $37^{\circ}C$. After rinsed in distilled water, these teeth were immersed in photodeveloping solution and exposed to fluorescent light for 6 hours. Teeth were then washed in distilled water to remove the photodeveloping solution, sectioned mesio-distally and evaluated. The results were as follows : 1. In the cervical portion, there was significant difference between Fuji II LC and other groups(Z-100, Dyract AP, Compoglass), Fuji II LC had the least value.(p<0.05) 2. In the cervical portion, there was not significant difference among Dyract AP, Z-100 and Compoglass. 3. In the occlusal portion, there was not significant difference among Dyract AP, Z-100 and Compoglass. From the results above, In enamel, microleakage of compomer such as Dyract AP and Compoglass resemble to that of composite resin. It is thought that it is due to characteristics of composite resin portion of compomer. But in dentin, microleakage of compomer is higher than that of resin modified glass ionomer cement, it is thought that in compomer, acid-base reaction is not developed with dentin.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.4
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• pp.438-444
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• 2010

Giomer is a recently developed light-cured resin-based material. This study compared compressive strength and microhardness of composite resin, giomer and compomer after 5000 times of thermocycling at $5^{\circ}C$ and $55^{\circ}C$. The following results were obtained. 1. Composite resin resulted in the highest compressive strengths both before and after thermocycling, followed by giomer and compomer. There were statistically significant differences between composite resin and giomer/compomer (p<0.05), but no statistically significant differences between giomer and compomer. 2. Both before and after thermocycling, microhardness values appeared in the order of composite resin, giomer and compomer with statistically significant differences in microhardness of composite resin, giomer and compomer (p<0.05). 3. After thermocycling, microhardness of composite resin, giomer and compomer decreased with a statistically significant difference (p<0.05). In conclusion, giomer demonstrates higher microhardness than compomer, but lower compressive strength and microhardness than composite resin. In addition, the decrease in microhardness and compressive strength after thermocycling proves the necessity for a thorough understanding in mechanical properties of restoration materials prior to their clinical application.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.2
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• pp.229-236
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• 2000

For the purpose of evaluating the microleakage of compomer restorations in cervical cavities of primary molars according to the length of etching time, an experiment was performed through next procedures. 48 extracted human primary molars were divided into 6 groups according to applied compomers and the etching time of 0, 15, 30 seconds. All the restorations were filled under the manufacturer's direction, and the degree of dye penetration was evaluated with stereomicroscope. The microleakage of etch group was measured and statistically analyzed and obtained the results as follows: 1. Compared with groups without etching, the degree of microleakage was reduced by acid etching the cavities (p<0.05). 2. There revealed similar preventive effects of microleakage when the teeth were etched for 15 seconds and 30 seconds respectively(p>0.05). 3. No significant difference was observed between two compomers examined in this study(p>0.05). It was, therefore, thought acid etching is effective to minimize the microleakage of compomer restorations in primary teeth, and in cases of performing, 15 seconds is adequate for etching.

• Restorative Dentistry and Endodontics
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• v.27 no.1
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• pp.12-15
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• 2002

The first purpose of present study was to compare the anticariogenic effect of compomer, resin modified glass ionomer cement and composite (RMGIC). The second purpose was to evaluate the recently introduced methods, which use confocal scanning micro-scope, in detecting initial caries around restoration. 2$\times$4$\times$1.5mm cavities were prepared from the recently extracted 50 human teeth on the buccal or lingual surface. The prepared teeth were randomly devided into 5 groups and restored with each filling material. Group 1: Dyract AP, Group 2: compoglass F, Group 3: F2000, Group 4: Z100. Group 5:Fuji II LC. The teeth were stored for 30 days in the distilled water, then stored in the buffer solution for artificial caries development: pH 4.3, lactic acid 100 mM, calcium 16 mM, phosphate 8mM, sodium azide 3mM. Then, the samples were sectioned longitudinally and examined with confical scanning microscope. The results showed that the use of compomer and resin modified glass ionomer cement showed caries inhibition zone whereas the composite did not. There was no difference in the width of caries inhibition zone between compomers and RMGIC. The confocal scanning microscope was useful in detecting initial caries around restoration.

• Restorative Dentistry and Endodontics
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• v.26 no.2
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• pp.171-179
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• 2001

The purpose of this study was to evaluate the shear bond strength of compomers according to dentin surface treatment. Two materials of compomer were devided into six groups. The compomer used in this study were Dyract AP(D) and F2000(F), Group 1 (DN) and 4(FN) were treated according to manufacturers instructions as control groups. Group 2(DE) and 5(FE) were treated with 37％ phosphoric acid and group 3(DA) and 6(FA) were treated with air abrasion unit (80 psi, 50 m aluminum oxide particles) respectively as experimental groups. After dentin surface treatment, compomers were bonded. Completed samples were stored in 100％ humidity. 37C during 7 days, and then, the shear bond strength of specimens were evaluated. The results were as follows: 1. In the case of Dyract AP, the shear bond strength was showed the highest value of 9.10 MPa in dentin surface treatment with air abrasion unit. but there were no significant differences to the other groups. 2. In the case of F2000. the shear bond strength was showed the highest value of 13.51MPa and there were significant differences to the other groups(p<0.05). 3. The shear bond strength of F2000 was higher than Dyract AP in each dentin surface treatment. and in the case of etching and air abrasion. there were significant differences(p<0.05). 4. As a result of observation of SEM. the most of fracture pattern was adhesive failure in group 1(DN), 2(DE) and 4(FN), and cohesive failure in group 3(DA), S(FE) and 6(FA).

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.4
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• pp.509-518
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• 2002

The purpose of this study was to evaluate the bonding of compomer to deciduous dentin which is known to have been developed to improve the weak properties of glass ionomer cement and composite resin. 120 sound primary molars were used for the shear bond strength test and another 24 for the scanning electron microscopic evaluation. Each material was ailed into polyethylene mold attached to exposed dentinal surface($3{\times}4mm$ in diameter) of sample blocks. Shearbond strength was measured using Universal testing machine and data were analyzed statistically with Oneway-ANOVA and Scheffe test. Scanning electron microscopic observation was performed in order to evaluate the pattern of distribution and penetration of resin tags and hybrid layer. Compomer groups(II-V) showed significantly higher bond strength values than glass ionomer group(I)(p<.05). Etching-compomer groups(III, V) showed the significantly higher bond strength than non-etching compomer groups(II, IV)(p<.05), but slightly lower values than composite resin group(VI) with no statistically significant difference(p>.05). No significantly different bond strength was found between compomer groups of different bonding system(p>.05). Scanning electron micrographs showed more irregular distribution of short and thin resin tags in non-etching compomer groups(II, IV) whereas the more regular and intimate distribution of long and thick tags in etching compomer groups(III, V) and composite resin group(VI). The evaluation of hybrid layer also showed more regular formation of thicker layer in etching compomer groups(III, V). Based on the results of present study, the use of compomer as an esthetic restorative material for primary molars might be justified.