• Restorative Dentistry and Endodontics
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• v.15 no.2
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• pp.122-126
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• 1990

To examine the microleakage of posterior esthetic restorative materials, using 2% methylene blue dye solution, dye penetration was determined with 80 permanent posterior teeth after thermocycling. The following results were obtained. 1. Amalgam group showed the most severe dye penetration of all test groups through the enamel and dentin / cementum margins. 2. Clearfil group showed much more dye penetration than P-50 at the enamel margin and than resin inlay system at the dentin / cementum margin. 3. Through the etched enamel margin, P-50 and resin inlay system groups showed no dye penetration, if any, but through the dentin / cementum margin, all test groups showed dye penetration. 4. Resin inlay system showed the least dye penetration of all test groups through the dentin / cementum margin.

• Restorative Dentistry and Endodontics
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• v.20 no.1
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• pp.214-234
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• 1995

The purpose of this work was to study the compatibility of several commercially available dentin adhesives with composite resins. In this study, V-shaped cavity preparations were created on both buccal and lingual surfaces of 60 extracted human premolars($3mm{\times}3mm{\times}2mm$ deep). Preparations were located such that the occlusal margins were on the enamel and the gingival margins were on the cementum(1mm below the CEJ). These specimens were randomly divided into three equal groups. Three dentin adhesives(Scotchbond Multi-Purpose, All Bond 2, Prisma Universal Bond 3)were applied to the cavity in accordance with each manufacturer's instructions. The teeth in each group were restored with four composite resins(Silux plus, Z100, Bisfil, Prisma TPH) in three increments, with each increment light-cured for 40 seconds. All specimens were exposed to 500 cycles of thermal stress. Specimens then placed in a silver nitrate solution(50% by weight) and stored in darkness for 24 hours. They were then immersed for 6 hours in photographic developing solution under flourescent light. Specimens were sectioned buccolingually through the center of the restoration and observed under a binocular stereoscope. To compare the marginal leakage, ANOVA and Dunkan's multiple range tests were used in analysis. Selected samples were further studied using scanning electron microscopy(XL20, Philips, The Netherlands). The results were as follows. 1. In all groups, the enamel margin showed significantly less leakage than the cementum margin. 2. No statistically significant differences were found in microleakage when composite resins were used with their proprietary dentin adhesives. 3. In comparison between dentin adhesives, Prisma Universal Bond 3 showed significantly less leakage at the enamel margin and Scotch bond multi-purpose showed significantly less leakage at the cementum margin than the other groups. 4. In comparison between composite resins, Silux Plus showed significantly more leakage than other groups at the enamel margin and no statistically significant differences were found in microleakage at the cementum margin. 5. According to the backscattered scanning electron microscope, microleakage occurred via gaps at the dentin adhesives/dentin interface.

• Restorative Dentistry and Endodontics
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• v.29 no.1
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• pp.58-67
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• 2004

The objectives of this study was to evaluate current visible light curing units regarding microhardness and microleakage. Fourty samples of composite resin(Z-250, 3M) were cured by different light curing units (Flipo, LOKKI; Credi II, 3M; XL 3000, 3M: Optilux 500, Demetron) in acrylic blocks. Microhardness was measured using a calibrated Vickers indenter on both top and bottom surfaces after 24 hours of storage in air at room temperature. Class V cavities were prepared on buccal and lingual surfaces of fourty extracted human molars. Each margin was on enamel and dentin/cementum. Composite resin(Z-250, 3M) was filled in cavities and cured by four different light curing units (Flipo, LOKKl; Credi II, 3M; XL 3000, 3M: Optilux 500, Demetron). The results of this syudy were as follows: Microhardness 1. Flipo showed low microhardness compared to Optilux 500, Credi II significantly in upper surface. Flipo didn't show a significant difference compared to XL 3000. 2. The microhardness resulting from curing with Flipo was lower than that of others on lower surfaces. Microleakage 1. Dentin margin showed significantly high dye penetration rate than enamel margin in all groups(p<0.05). 2. No significant differences were found on both enamel and dentin margin regarding curing units.

• The Journal of Korean Academy of Prosthodontics
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• v.36 no.6
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• pp.789-805
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• 1998

The purpose of this study was to compare the microleakage of the IPS Empress ceramic crown according to 1) margin types such as rounded shoulder and bevel, 2) margin locations such as enamel and dentine, 3) resin cement types such as Variolink and Bistite. For this study, 80 extracted premolar teeth were used. After 10 experimental dies were prepared for each group, the IPS Empress ceramic crowns were fabricated on the dies and cemented with one of two types of resin cement. After 1,000 cycles of thermal changes were given with the thermocycling unit, each specimen was sectioned with a low speed diamond saw in both the buccolingual and the mesiodistal direction. The microleakage was then measured with a stereo microscope. The obtained results were as follows : 1. Every experimental group showed microleakage. The microleakage of the crowns which had a rounded shoulder on enamel cemented with Variolink was the lowest of all. The resulting rank of the mean microleakage was rounded shoulder on enamel using Variolink(0.601mm), rounded shoulder on enamel using Bistite (0.794mm), bevel on enamel using Variolink (0.826mm), rounded shoulder on dentine using Variolink(1.054mm), bevel on enamel using Bistite(1.087mm), rounded shoulder on dentine using Bistite(1.176mm), bevel on dentine using Variolink(1.258mm), and bevel on dentine using Bistite(1.467mm). 2. The statistically significant differences in the microleakage were found in 4 cases: rounded shoulder on enamel using Variolink and bevel on dentine using Variolink, rounded shoulder on enamel using Variolink and bevel on dentine using Bistite, rounded shoulder on enamel using Bistite and bevel on dentine using Bistite, bevel on enamel using Variolink and bevel on dentine using Bistite. 3. The microleakage of rounded shoulder finish line was lower than that of bevel finish line. The statistically significant differences were found with respect to the type of finish lines. 4. The microleakage of the finish line on enamel was lower than that of finish line on dentine. The statistically significant differences were found with respect to the location of the finish lines. 5. The microleakage of the Variolink cement was lower than that of the Bistite cement. The statistically significant differences were found with respect to the resin cements.

• Restorative Dentistry and Endodontics
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• v.32 no.4
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• pp.327-334
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• 2007

The purpose of this study was to evaluate the effect of burs on microleakage of Class V resin restorations when a self-etching primer adhesive was used. Forty Class V cavities were prepared with four different cutting burs on extracted third molars, and divided into one of four equal groups (n = 10); Group 1-plain cut carbide bur (no. 245), Group 2-cross cut carbide bur (no. 557), Group 3-fine diamond bur (TF-21F), Group 4-standard diamond bur (EX-41). The occlusal and gingival margin of cavities was located in enamel and dentin, respectively. Cavities were treated with Clearfil SE Bond and restored with Clearfil AP-X. Specimens were thermocycled, immersed in a 2% methylene blue solution for 24 hours, and bisected longitudinally. They were observed leakages at enamel and dentinal margins. Data were analyzed using Mann-Whitney and Wilcoxon signed ranked test. The results of this study were as follows; 1. At enamel margin, microleakage of group 4 was statistically higher than those of group 1, 2 and 3 (p < 0.01). 2. At dentinal margin, microleakage of group 4 was statistically higher than group 3 (p < 0.01), but group 1 and 2 were not statistically different with group 3 and 4. 3. Enamel microleakage was statistically higher than dentinal microleakage in group 1, 2 and 3 (p < 0.05), but statistical difference between the microleakage of enamel and dentinal margin was not in Group 4. In conclusion, the use of coarse diamond bur showed high microleakage at both enamel and dentinal margin when Clearfil SE Bond was used in class V cavity.

• Restorative Dentistry and Endodontics
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• v.26 no.2
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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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• v.20 no.1
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• pp.152-163
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• 1995

This experiment was performed to observe the adhesion pattern and microleakage in the gingival margin according to variation in the resin cement thickness which results from thickness of Die spacer. which is considered to effect the adaptability of the composite resin inlays. Clearfil CR inlays were fabricated on stone models with CR Sep applicated once and Nice fit twice, 4 times, and 6 times each. After 2nd curing within the CRC-100 oven, CR inlays were cemented with CR inlay cement. Dye(2% methylene blue) penetration and adhesion pattern were evaluated after sectioning of gingival margin into :3 pieces. The results were as follows ; 1. The thickness of resin cement showed unevenchanging pattern with that of die spacer, namely, it was increased until 4 times' application of Nice-Fit but was decreased with 6 times' application of that. 2. The degree of dye penetration wasn't affected by cement thickness within a limited value. 3. Most of dye penetration was shown through the interface between cement and enamel rather than the interface between cement and CR inlay. This shows that the affinity of resin cement for CR inlay was superior to the adhesive strength with tooth structure. 4. No gap was found at the interface between enamel and cement but some showed separation between dentin and cement. It is concidered that the contraction force of cement was less than the bond strength with the enamel. 5. Lots of voids were found in the CR inlay and resin cement. There was a pooling tendency of bonding agent and cement in the axiogingival line angle portion. 6. In some specimens, cracks were shown in enamel margin. From this it could be considered that cavity preparation and surface treatment weakened the tooth structure.

• Restorative Dentistry and Endodontics
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• v.18 no.2
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• pp.447-462
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• 1993

To evaluate the marginal leakage in Class V cavity this study has been undertaken to compare the sandwich technique with the conventional method, and find out the effect of lining material, lining method, and polishing time on sandwich technique. Ninty extracted teeth were divided into eight test groups and a control group, and were prepared with a buccal Class V cavity. Four test groups were lined with Dentin Cement whereas the other four test groups were lined with Vitrabond. Half of the either group were lined 0.5mm short of the carvosurface margin and the rest were lined completely to the carvosurface margin. The four subgroups were further divided into specimens which were polished immediately and 24 hours after resin filling. The polished specimens were immersed in $37^{\circ}C$, 0.5% methylene blue solution for 24 hous after thermocycling at $5^{\circ}C$ and $55^{\circ}C$, 200 times and buccolingually sectioned. The sectioned specimens were examined dye penetration under the light microscope. The following results were obtained, 1. At the enamel margin, the conventional method showed a lower microleakage than the sandwich technique. The difference between the control and Vitrabond group was statistically significant(P<0.05), but no difference between the control and Dentin Cement group, and between the lining materials was observed. 2. At the dentinal margin, the sandwich technique showed a significant lower amount of microleakage (P<0.05), but there was no significant difference between the lining materials. 3. Regardless of the lining material, lining method, and polishing time used, values of microleakage were significantly higher at the dentinal margin compared to the enamel margin(P<0.05). 4. In specimens till the cavosurface margin, microleakage at the dentinal margin was less with the light-cured base than with the chemically-cured base, but there was no siginificantly difference between the lining materials regarding the lining method and polishing time. 5. The lining material, lining method, and polishing time did not affect the amount of micro leakage in the sandwich technique(P<0.05).

• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.2
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• pp.147-155
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• 2008

Three groups of dentin bonding agents (5th generation Single Bond 2.0 and two 6the generation Prompt L-Pop, AdheSE) applied to class V cavities (upper portion with enamel margin and lower portion with dentin margin) prepared at buccal and lingual portion of premolars and molars. Each groups consist of 30 teeth. Devide into two groups, one without thermocycling and the other thermocycled. After then, infiltrate methylene blue into the gap between restoration and tooth. Within non-thermocycled groups, Single Bond 2.0 group shows lesser leakage at enamel margin than other two bonding agents (p <.05) but shows more leakage at dentin margin than other two bonding agents. (p <.05) Within thermocycled groups, Single Bond 2.0 group shows lesser leakage at both enamel and dentin margins. (p <.05)

• Restorative Dentistry and Endodontics
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• v.30 no.5
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• pp.363-371
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• 2005

This study investigated the effect of thickness of flowable resin lining on marginal leakage in class II composite restorations. 80 experimental teeth were prepared with class II preparations with enamel margin or dentin margin. Each group was devided into four groups according to flowable resin lining thickness ; Control group - no flowable resin lining, Group 1 - 0.5 mm flowable resin lining, Group 2 - 1 mm flowable resin lining, Group 3 - 2 mm flowable resin lining. The cavities were restored using Scotchbond Multi-Purpose adhesive system, Filtek Flow and Filtek Z 250 composite resin. Following one day storage in distilled water, the restored teeth were thermocycled for 500 cycles and immersed in $2\%$ methylene blue for 24 hours. The results of this study were as follows : 1. Ranking of mean microleakage scores at the enamel margins was Group 1 < Control = Group 2 < Group 3. The microleakage of Group 3 was significantly higher than that of Control, Group 1 and Group 2 (p < 0.05). 2. Ranking of mean microleakage scores at the dentin margins was Group 1 < Group 2 < Control < Group 3. The microleakage of Group 3 was significantly higher than that of Control, Group 1 (p < 0.05) 3. Compared with microleakage between the enamel and dentin margins, enamel margin group were significantly lower than dentin margin group.