• Restorative Dentistry and Endodontics
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• 제26권2호
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• pp.153-161
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• 2001

The purpose of this study was to evaluate microleakage of six current dentin bonding systems. In this in vitro study, class V cavities were prepared on buccal and lingual surfaces of thirty extracted human molars. Each margin was on enamel and dentin/cementum. Experimental teeth were randomly divided into six groups of 5 each. Group 1 : Scotchbond Multi-Purpose; Group 2 : Single Bond; Group 3 : Prime&Bond NT ; Group 4 : Clearfil Liner Bond 2 ; Group 5 : MAC Bond II ; Group 6 : One-up Bond F. The bonding agent and composite resin were applied to class V cavities according to manufacturer's directions. After thermocycling, the specimens were immersed in 0.5% basic fuchsin dye solution for 6 hours and sectioned longitudinally through the center of the restoration with a low speed diamond saw. The degree of microleakage was measured as the extent of dye penetration under the stereomicroscope at $\times$20. The data were analyzed using one way ANOVA. When significant differences found. multiple comparisons were made using Duncan's Multiple Range Test. The results of this study were as follows: 1. In all groups, leakage value seen at the enamel margin was significantly lower than that seen at the dentin margin(P<0.001). 2. At the enamel margin, none of the dentin bonding systems used in this study showed statistically significant difference in leakage values(P<0.05). 3. At the cementum margin, group 3 showed the highest leakage value, and others were decreased as group 5, 6, 4 in that order, and group 1, 2 showed the lowest leakage value. There was statistically significant difference between group 3 and the other groups except for group 5(P<0.05).

• Restorative Dentistry and Endodontics
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• 제22권2호
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• pp.680-692
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• 1997

New bonding agent systems have been supplied which operators can simply apply to conditioned tooth surfaces. The purpose of this study was to evaluate the shear bond strengths and the microleakages of three bonding agents and composite resins to dentin. Seventy-five extracted human maxillary and mandibular molar teeth were used in this study. For the shear bond strength test, the entire occlusal dentin surfaces of thirty teeth were exposed with Diamond Wheel Saw and smoothed with Lapping and Polishing Machine (South Bay Technology Co., U.S.A). For the microleakage test, Class V cavities were prepared in the buccal surfaces of fourtyfive teeth. They were randomly assigned into 3 groups according to dentin bonding agents ($Scotchbond^{TM}$ Multi-Purpose plus, ONE-$STEP^{TM}$ and Prime & $Bond^{TM}$)and composite resins (Z-100, $Aelitefil^{TM}$ and TPH $Spectrum^{TM}$) to be used. Bonding agents and composite resins were bonded to exposed dentin surfaces of the tooth crown and to Class V cavities on the buccal surfaces respectively according to manufacturer's directions. The shear bond strengths were measured by universal testing machine($U^{TM}$ AGS-100, Japan). In addition, the degree of micro leakage at the occlusal and gingival margin was examined by 2 % methylene blue and stereomicroscope(Olymous SZH 10, Japan). The results were as follows: 1. The shear bond strength to dentin was the highest value in SBMP-Plus group($16.68{\pm}7.38$ MPa) and the lowest value in Prime & Bond group($11.61{\pm}5.82$ MPa), but there was no significant difference of shear bond strength among three groups. 2. The degree of microleakage at both occlusal and gingival margin was showed the lowest in SBMP-Plus group and the highest in ONE-STEP group. 3. At both occlusal and gingival margin, there was significant difference of microleakage between SBMP-Plus and ONE-STEP/ Prime & Bond groups(p<0.05), but no significant difference of microleakage between ONE-STEP and Prime & Bond group(p>0.05).

• 대한소아치과학회지
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• 제23권2호
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• pp.401-414
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• 1996

The purpose of this study was to compare the marginal leakage of resin liner which was used as a liner to amalgam restoration. Control group composed of no liner group, copalite group and experimental group composed of All-bond 2, Vitrebond, Superbond D-liner applied groups were evaluated. Cl.V preparation with a size of $3{\times}2{\times}1.5mm$ on 70 extracted primary molars were made and applied appropriate liners for each groups. After amalgam filling and polishing, polished specimens underwent temperature changed from $5^{\circ}C\;to\;55^{\circ}C$ a thousand times. After thermocycling, specimens were placed in 2% methylene blue dye solution for 72 hours in an incubator set at $37^{\circ}C$. The teeth were sectioned buccolingually and the degree of dye penetration was observed with a spectroscopy. (${\times}30$) The following results were obtained. 1. Vitrebond, All-bond 2, Superbond D-liner group exhibited a statistically significant lower degree of dye penetration than no liner and copalite group. (Kruskal-Wallis analysis, P<0.05) 2. No liner group and copalite group exhibited a similar degree of dye penetration. (Mann-Whitney analysis, P>0.05) 3. All-bond 2 group exhibited a statistically significant lower degree of dye penetration than Vitrebond group, (Mann-Whitney analysis, P<0.05) Superbond D-liner group also exhibited a lower degree of dye penetration than Vitrebond group but was statistically insignificant. (Mann-Whitney analysis, P>0.05)

• 대한소아치과학회지
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• 제25권1호
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• pp.47-61
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• 1998

The purpose of this study was to compare the microleakage pattern of glass ionomer with resin restoration in microleakage pattern of primary and permanent teeth. Microscopical observation of interface between tooth structure and restoration was also performed. 80 and 8 sound molar teeth were used for the microleakage test and SEM study respectively. Data were analyzed statistically using ANOVA test and/or t-Test. The results of the present study were as follows: 1. According to the result of microleakage pattern between primary and permanent tooth, primary tooth generally showed more micro leakage than permanent tooth in all groups (p<.05). 2. In the resin-filled groups, occlusal margin was shown to have more microleakage than gingival margin(p<.05). Whereas the glass ionomer-filled groups showed no statistically significant differences between them(p>.05). 3. No statistically significant differences in microleakage could be found between two different resin groups(p>.05), while Fuji II LC group showed less microleakage than Ketac-Fil group(p>.05). 4. The various type hybrid layer was evident under SEM in resin-filled groups both in primary and permanent teeth with generally thicker layer in primary group. Among glass-ionomer group, Fuji II LC group showed more intact adhesion to tooth surface than Ketac-Fil group

• 한국세라믹학회지
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• 제36권8호
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• pp.791-798
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• 1999

다공성 NiO-YSZ 기판위에 전착법(EPD; Electrophoretic Deposition)법과 담금(Dip-coating)법에 의해 음극지지형 고체연료전지용 이트리아 안정화 지르코니아 박막 제조법을 연구하였다. 이를 위해 슬러리 농도 및 시간에 따른 박막의 무게, 박막의 결함 및 미세구조변화에 영향을 주는 제조조건들을 살펴 봄으로써 전착법과 담금법의 차이를 보았다. 담금법에서는 막생성 초기인 30초까지 막의 무게가 증가하지만 그 후에는 탈락이 일어나 시간을 증가하여도 막의 무게가 오히려 감소하였다. 전착법에서는 임계 인가전류 이상에서 시간에 따라 막의 무게가 증가하고 균일하고 치밀한 막이 형성하였다 전장이 매우 낮은 0.035 mA/$cm^2$ 의 정전류를 120초 이상 장시간 인가하면 막의 흘러내림(sagging)으로 인한 결함이 발생하였다. 전착법에 의해 균일하고도 치밀하게 가스 누출성이 없는 음극지지형 고체산화물 연료전지에 적합한 전해질 박막을 제조할 수 있었다.

• Restorative Dentistry and Endodontics
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• 제28권5호
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• pp.363-368
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• 2003

The purpose of this study is to evaluate the effect of additional enamel etching with phosphoric acid on the microleakage of the adhesion of self-etching primer system. Class V cavity($4mm{\times}3mm{\times}1.5mm$) preparations with all margins in enamel were prepared on buccal surface of 42 extracted human upper central incisor teeth. Prepared teeth were randomly divided into 3 groups. Group 1：no additional pretreatment with 37% phosphoric acid (NE). Group 2：additional pretreatment with 37% phosphoric acid for 10 seconds (E10s). Group 3：additional pretreatment with 37% phosphoric acid for 20 seconds (E20s). The adhesives(Clearfil SE $Bond^{\circledR}$, Kuraray, Osaka, Japan) and composite resins(Clearfil $AP-X^{\circledR}$, Osaka, Kuraray, Japan) were applied following the manufacturer's instructions. All the specimens were finished with the polishing disc(3M dental product, St Paul, MN, USA), thermocycled for 500 cycles between $5^{\circ}C$ and $55^{\circ}C$ and resected apical 3-mm root. 0.028 stainless steel wire was inserted apically into the pulp chamber of each tooth and sealed into position with sticky wax. Surrounding tooth surface was covered with a nail varnish 2 times except areas 1mm far from all the margins. After drying for one day, soaked the samples in the distilled water. Microleakage was assessed by electrochemical method(System 6514, $Electrometer^{\circledR}$), Keithley, USA) in the distilled water. In this study, the microleakage was the lowest in group 1 (NE) and the highest in group 3(E20s)(NE

• Restorative Dentistry and Endodontics
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• 제24권2호
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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.

• Restorative Dentistry and Endodontics
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• 제20권2호
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• pp.721-731
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• 1995

The purpose of this study was to evaluate the adaptability to tooth structure of light-cured glass ionomer cements. In this, study, class V cavities were prepared on the buccal surfaces of thirty extracted human premolar teeth, and they were randomly assigned into 3 groups with 10 teeth. The cavities of each groups were filled with the Fuji II LC(GC International Corp., Japan), Vitremer(3M Dental Products Division, U.S.A) and VariGlass VLC(Caulk/Dentsply Inc., U.S.A.). The specimens were immersed in 1% methylene blue solution and stored in 100% realtive humidity at $37^{\circ}C$ for 5 days. And then, the specimens sectioned buccolingually. Degree of eke penetration at tooth--restoration interfaces were examined by magnifying glass at occlusal and gingival margin. The results were as follows : 1. On the occlusal margin, among the experimental groups, the group 2 showed the lowest microleakage($1.40{\pm}1.17$) and the group 1 showed the highest microleakage($3.10{\pm}0.99$). There was significant difference between group 1 and group 2(P<0.01). 2. On the gingival margin, among the experimental groups, the group 2 showed the lowest microleakage($2.50{\pm}1.08$) and the group 1 showed the highest microleakage($3.50{\pm}0.84$). But there was not significant. difference among the experimental groups(P>0.05). 3. The degree of microleakage at occlusal margin was less than gingival margin in all experimental groups.

• Restorative Dentistry and Endodontics
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• 제25권1호
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• pp.85-90
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• 2000

For more esthetic treatments the use of composite in molar areas are increasing. But polymerzation shrinkage that cause marginal leakage and cuspal deflection has been the problems of composites. The purpose of this study is to compare the effect of low intensity curing and polishing period on marginal leakage. Cavities were prepared on the buccal or lingual surface of forty five sound extracted human teeth and etching, application of bonding agent and filling of composite was done. Group 1 was light cured at intensity of 600$mW/cm^2$ for 41 seconds and polished. Group 2 was light cured at intensity of 300$mW/cm^2$ for 2 seconds and polished and after polishing it was light cured for 40 seconds at 600$mW/cm^2$. Group 3 was light cured at intensity of 300$mW/cm^2$ for 2 seconds and waited for 5 minutes and after curing at 600$mW/cm^2$ for 40 seconds polishing was done. The specimens were thermocycled at $5^{\circ}C$ and $55^{\circ}C$ for 1000 cycles and immersed in 2% methylene blue solution for 24 hours. Composite-tooth interface was examined under stereobinocular microscope for dye penetration. The results were as follows : 1. Group which were cured at low intensity and polished after curing at high intensity showed less marginal leakage than group which were cured at high intensity for 41 seconds(p<0.05). 2. Marginal leakage between group which were cured at low intensity and polished immediately and group which were cured at high intensity for 41 second were not significantly different. Light curing at low intensity can reduce marginal leakage but polishing immediately after curing at low intensity for short time can affect marginal leakage.

• Restorative Dentistry and Endodontics
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• 제25권1호
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• pp.56-62
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• 2000

The purpose of this study was to assess the effects of restorative materials on the marginal leakage of wedge-shaped class V cavity. The study was performed in vitro in 25 defect-free permanent, extracted teeth. Wedge-shaped class V cavities were prepared and then the teeth were randomly selected and restored according to the following. Group A : restoration with Tetric Ceram(composite resin) Group B : restoration with Tetric flow(flowable resin) Group C : restoration with Compoglass after acid etching(compomer) Group D : restoration with Compoglass(compomer) Group E : restoration with Fuji II LC improved(resin-modified GIC) After thermocycling, the specimens were immersed in 5% basic fuchsin solution for 6 hours and sectioned longitudinally through the center of the restoration. The degree of marginal leakage was measured as the extent of dye penetration under the stereomicroscope. The data were analysed using one-way ANOVA. When significant differences found, multiple comparisons were made using Duncan's Multiple Range Test. The results were as follows: 1. The occlusal margins of all groups except for Fuji II LC improved showed lesser leakage than gingival margins and there was statistically significant difference(p<0.05). 2. At the occlusal margins, group A, B showed same marginal leakage scores, and others were decreased as group C, D, E in that order. There were statistically significant difference between group A, Band group D, E, group C and group E(p<0.05). 3. At the gingival margins, group B, C showed same marginal leakage scores, and others were decreased as group A, D, E in that order. But there was statistically significant difference between group B, C and group E(p<0.05). 4. In the Compoglass restoration, acid-etching technique was beneficial for marginal sealing ability at all of margins. But there was no statistically significant difference (p>0.05). In the restorations for wedge-shaped class V cavities, resin restoration with acid etching technique is recommended.