The purpose of this study was to evaluate the microtensile bond strength (µTBS), failure modes and bonding interfaces of self-etching and three self-adhesive resin cements to dentin and indirect composite resin.

Cylindrical composite blocks (Tescera, Bisco Inc.) were luted with resin cements (PA: Panavia F 2.0, Kuraray Medical Inc., RE: RelyX Unicem Clicker, 3M ESPE., MA: Maxem, Kerr Co., BI: BisCem, Bisco Inc.) on the prepared occlusal dentin surfaces of 20 extracted molars. After storage in distilled water for 24 h, 1.0 mm × 1.0 mm composite-dentin beams were prepared. µTBS was tested at a cross-head speed of 0.5 mm/min. Data were analyzed with one-way ANOVA and Tukey's HSD test. Dentin sides of all fractured specimens and interfaces of resin cements-dentin or resin cements-composite were examined at FE-SEM (Field Emission-Scanning Electron Microscope).

In conclusion, PA and RE showed higher bond strength and closer adaptation than MA and BI when indirect composite blocks were luted to dentin using a self-etching and three self-adhesive resin cements.

The purpose of this study was to compare the microshear bond strength of a self-etching primer adhesive to dentin prepared with different diamond points, carbide burs and SiC papers, and also to determine which SiC paper yield similar strength to that of dentinal surface prepared with points or burs.

Fifty-six human molar were sectioned to expose the occlusal dentinal surfaces of crowns and slabs of 1.2 mm thick were made. Dentinal surfaces were removed with three diamond points, two carbide burs, and three SiC papers. They were divided into one of eight equal groups (n = 7); Group 1: standard diamond point(TF-12), Group 2: fine diamond point (TF-12F), Group 3: extrafine diamond point (TF-12EF), Group 4: plain-cut carbide bur (no. 245), Group 5: cross-cut carbide bur (no. 557), Group 6 : P 120-grade SiC paper, Group 7: P 220-grade SiC paper, Group 8: P 800-grade SiC paper.

Clearfil SE Bond was applied on dentinal surface and Clearfil AP-X was placed on dentinal surface using Tygon tubes. After the bonded specimens were subjected to uSBS testing, the mean uSBS (n = 20 for each group) was statistically compared using one-way ANOVA and Tukey HSD test.

In conclusion, the use of extrafine diamond point is recommended for improved bonding of Clearfil SE Bond to dentin. Also the use of P 220-grade SiC paper in vitro will be yield the results closer to dentinal surface prepared with fine diamond point or carbide burs in vivo.

The purpose of this study was to compare the microleakage of low and high viscosity flowable resins in class V cavities applied with 1-step adhesives.

Forty class V cavities were prepared on the cervices of buccal and lingual surfaces of extracted molar teeth and divided into four groups (n=8). Cavities were restored with AQ Bond Plus/Metafil Flo α, G-Bond/UniFil LoFlo Plus (Low flow groups), AQ Bond Plus/Metafil Flo and G-Bond/UniFil Flow (High flow group), respectively.

Specimens were immersed in a 2% methylene blue solution for 24 hours, and bisected longitudinally. They were observed microleakages at the enamel and dentinal margins.

In conclusion, the low viscosity flowable resins showed lower marginal microleakage than do the high viscosity flowable resins in class V cavities.

The purpose of this study was to evaluate the effect of a desensitizer on dentinal bond strength in cementation of composite resin inlay. Fifty four molar teeth were exposed the occlusal dentin. Class I inlay cavities were prepared and randomly divided into six groups. Control group ; no agent, Group 1 ; Isodan, Group 2 ; One-step, Group 3 ; All-Bond SE, Group 4 ; Isodan + One-step, Group 5 ; Isodan + All-Bond SE.

Desensitizing agent and dentin bonding agents were applied immediately after the completion of the preparations. Impressions were then made. The composite resin inlays (Tescera, Bisco) were fabricated according to the manufacturers' guidelines. Cementation procedures followed a standard protocol by using resin cement (Bis-Cem, Bisco). Specimens were stored in distilled water at 37℃ for 24 hours.

All specimens were sectioned to obtained sticks with 1.0 × 1.0 mm² cross sectional area. The microtensile bond strength (µTBS) was tested at crosshead speed of 1 mm/min. The data was analyzed using oneway ANOVA and Tukey's test. Scanning electron microscopy analysis was made to examine the details of the bonding interface.

1. Group 1 showed significantly lower µTBS than other groups (p<0.05).

2. There was no significant difference between the µTBS of Group 3 and Group 5.

3. The µTBS of Group 4 showed significantly lower than that of Group 2 (p<0.05).

In conclusion, a desensitizer (Isodan) might have an adverse effect on the bond strength of composite resin inlay to dentin.

The purpose of this study was to compare the effect of curing methods of adhesive resins and resin cements in the root canal. Crown portions of 32 single-rooted mandibular premolars were removed. Routine endodontic treatment was done, and 9 mm deep post spaces were prepared within root canals. No. 3 FRC Postec posts (Ivoclar-Vivadent AG, Liechtenstein) were cemented in the post spaces by self-(SC) or light-curing (LC) using two dual-cured adhesives (Adper Scotchbond multi-purpose plus and Exite DSC )and resin cements (RelyX ARC and Variolink II). They were assigned to 4 groups (n=8); R-SC, R-LC, V-SC, V-LC group.

After stored in distilled water for 24 hours, each root was transversally sectioned with 1.5 mm thick and made three slices. The specimens were subjected to push-out test in a universal testing machine (EZ Test, Shimadzu Co., Japan) with a crosshead speed of 1 mm/min. The data were analyzed with repeated ANOVA and one-way.

ANOVA. Also the interface of post-resin cement and resin cement-canal wall of each group was observed under FE-SEM.

When fiber posts were cemented into the root canal using total-etch adhesives, the bond strength and adaptation between post and root canal dentin was affected by curing method. Self-cure of adhesives and resin cements showed higher bond strength and closer adaptation than light-cure of them.

The purpose of this study was to compare the push-out strength of a fiber post cemented with various resin cements. Newly extracted 36 human mandibular premolars which had single root canal were selected and their crown portions were removed. The root canal was instrumented using PROTAPER™ system and obturated using continuous wave technique. In each root, a 9-mm deep post space was prepared. #2 translucent fiber post (DT Light post, Bisco Inc., Schaumburg, IL, U.S.A.) was cemented using injection technique with Uni-dose needle tip (Bisco) and six different resin cements. The tested resin cements were Duo-Link (Bisco Inc., Schaumburg, IL, U.S.A.), Variolink II (Ivoclar-Vivadent AG, Schann, Liechtenstein), Panavia F (Kuraray Medical Inc., Okayama, Japan), Multilink Automix (Ivoclar-Vivadent AG, Schann, Liechtenstein), RelyX Unicem (3M ESPE Dental Products, St. Paul, MN, U.S.A.), and Maxcem (Kerr Co., CA, U.S.A.). After storage in distilled water for 24 hours, each root was transversally sectioned into approximately 1-mm thick sections. This procedure resulted in 6 serial sections per root. Push-out test was performed using a universal testing machine (EZ Test, Shimadzu Co.) with a crosshead speed of 1 mm/min. The data were analyzed with one-way ANOVA and Tukey HSD (p=0.05).

The push-out strength of the groups which cemented fiber post with Panavia F and Multilink Automix were lower than those of the other groups. But, there were no statistically significant difference among groups at a probability level of 0.05.

The purpose of this study was to compare the microtensile bond strength in Class I cavities associated with different light curing modes of same light energy density.

Occlusal enamel was removed to expose a flat dentin surface and twenty box-shaped Class I cavities were prepared in dentin. Single Bond (3M Dental product) was applied and Z 250 was inserted using bulk technique. The composite was light-cured using one of four techniques; pulse delay (PD group), soft-start (SS group), pulse cure (PC group) and standard continuous cure (CC group). The light-curing unit capable of adjusting time and intensity (VIP, Bisco Dental product) was selected and the light energy density for all curing modes was fixed at 16 J/cm². After storage for 24 hours, specimens were sectioned into beams with a rectangular cross-sectional area of approximately 1 mm². Microtensile bond strength (µTBS) test was performed using a universal testing machine (EZ Test, Shimadzu Co.). The results were analyzed using oneway ANOVA and Tukey's test at significance level 0.05. The µTBS of PD group and SS group was higher than that of PC group and CC group.

Within the limitations of this in vitro study, modification of curing modes such as pulse delay and soft start polymerization can improve resin/dentin bond strength in Class I cavities by controlling polymerization velocity of composite resin.

The purpose of this study was to compare the normal and two times of application time of six self-etching primers applied to enamel using microshear bond strength (uSBS) test and the finding of scanning electronic microscope (SEM).

Crown of sixty human molars were bisected mesiodistally and buccal and lingual enamel of crowns were partially exposed and polished with 600 grit SiC papers. They were divided into one of two equal groups subdivided into one of six equal groups (n = 10) by self-etching primer adhesives.

After the same manufacture's adhesive resin and composites were bonded on the enamel surface of each group, the bonded specimens were subjected to uSBS testing and also observed under SEM.

In conclusion, generally two times of primer application time increased the enamel uSBS, especially with the statistical increase of bond strength in adhesives involving high-pH primers.

The purpose of this study was to evaluate the effect of passive or active application of primer and coat times of bond on the shear bond strength when a self-etching primer adhesive (Clearfil SE Bond) was applied to enamel surface.

Crowns of sixteen human molars were selected. Buccal and lingual enamels of crowns were partially exposed and slabs of 1.2 mm thick were made. They were divided into one of four equal groups (n = 8). Group 1: passive application of Primer and 1 coat of Bond, Group 2: active application of Primer and 1 coat of Bond, Group 3: passive application of Primer and 2 coats of Bond, Group 4: active application of Primer and 2 coats of Bond. Clearfil AP-X was bonded to enamel suface of each group using Tygon tubes. The bonded specimens were subjected to microshear bond strength (uSBS) testing with a crosshead speed of 1 mm/min.

The results of this study were as follows;

The uSBS of Group 1 was the lowest among groups and the uSBS of Group 4 was the highest.

The purpose of this study was to compare the marginal microleakage of different 2-step adhesive systems in Class V cavities prepared with different diamond points.

Forty Class V cavities were prepared with two different (coarse or fine) diamond points on cervical third of extracted molars. The occlusal and gingival margin of cavities was located in enamel and dentin, respectively. They were divided into one of four equal groups (n = 10) and ; Group 1-prepared with coarse diamond point (EX-41), restored with Single Bond and Z 250, Group 2-prepared with fine diamond piont (TF-21F), restored with Single Bond and Z 250, Group 3-prepared with coarse diamond point (EX-41), restored with Clearfil SE Bond and Clearfil AP-X, Group 4-prepared with fine diamond point (TF-21F), restored with Clearfil SE Bond and 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.

In this study, marginal microleakage of Single Bond was not affected by type of diamond points. But Clearfil SE Bond showed higher marginal microleakage at both enamel and dentinal margin when Class V cavity was prepared with coarse diamond point.

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.

This study was to compare the microshear bond strength (µSBS) of light- and chemically cured composites to enamel coupled with four 2-step self-etch adhesives and also to evaluate the incompatibility between 2-step self-etch adhesives and chemically cured composite resin.

Crown segments of extracted human molars were cut mesiodistally, and a 1 mm thickness of specimen was made. They were assigned to four groups by adhesives used: SE group (Clearfil SE Bond), AdheSE group (AdheSE), Tyrian group (Tyrian SPE/One-Step Plus), and Contax group (Contax). Each adhesive was applied to a cut enamel surface as per the manufacturer's instruction. Light-cured (Filtek Z250) or chemically cured composite (Luxacore Smartmix Dual) was bonded to the enamel of each specimen using a Tygon tube. After storage in distilled water for 24 hours, the bonded specimens were subjected to µSBS testing with a crosshead speed of 1 mm/minute. The mean µSBS (n=20 for each group) was statistically compared using two-way ANOVA, Tukey HSD, and t test at 95% level. Also the interface of enamel and composite was evaluated under FE-SEM.

The results of this study were as follows;

1. The µSBS of the SE Bond group to the enamel was significantly higher than that of the AdheSE group, the Tyrian group, and the Contax group in both the light-cured and the chemically cured composite resin (p < 0.05).

2. There was not a significant difference among the AdheSE group, the Tyrian group, and the Contax group in both the light-cured and the chemically cured composite resin.

3. The µSBS of the light-cured composite resin was significantly higher than that of the chemically cured composite resin when same adhesive was applied to the enamel (p < 0.05).

4. The interface of enamel and all 2-step self-etch adhesives showed close adaptation, and so the incompatibility of the chemically cured composite resin did not show.

The purpose of this study was to evaluate the difference of surface roughness of composite resin according to composite resin type, polishing methods, and use of resin sealant.

Two hundred rectangular specimens, sized 8 × 3 × 2 mm, were made of Micro-new (Bisco, Inc., Schaumburg, IL, U.S.A) and Filtek Supreme (3M ESPE Dental Products, St. Paul, MN, U.S.A.), and divided into two groups; Micronew-M group, Filtek Supreme-S group. Specimens for each composite group were subdivided into five groups by finishing and polishing instruments used; M1 & S1 (polyester strip), M2 & S2 (Sof-Lex disc), M3 & S3 (Enhance disc and polishing paste), M4 & S4 (Astropol), and M5 & S5 (finishing bur). Polished groups were added letter B after the application of resin surface sealant (Biscover), eg, M1B and S1B.

After specimens were stored with distilled water for 24 hr, average surface roughness (Ra) was taken using a surface roughness tester. Representative specimens of each group were examined by FE-SEM (S-4700: Hitachi High Technologies Co., Tokyo, Japan). The data were analysed using paired t-test, ANOVA and Duncan's tests at the 0.05 probability level. The results of this study were as follows;

The lowest Ra was achieved in all groups using polyester strip and the highest Ra was achieved in M5, S5 and M5B groups using finishing bur. On FE-SEM, M1 and S1 groups provided the smoothest surfaces, M5 and S5 groups were presented the roughest surfaces and voids by debonding of filler on the polished specimens.

In conclusion, surface roughness by polishing instruments was different according to type of composite resin. Overall, polyester strip produced the smoothest surface, but finishing bur produced the roughest surface. Application of resin sealant provided the smooth surfaces in specimens polished with Enhance, Astropol and finishing bur, but not provided them in specimens polished with Sof-Lex disc.

This study compared the microshear bond strength (µSBS) of light-cured and dual-cured composites to enamel bonded with three self-etching adhesives. Crown segments of extracted human molars were cut mesiodistally, and 1 mm thickness of specimen was made. They were assigned to three groups by used adhesives: Xeno group (Xeno III), Adper group (Adper Prompt L-Pop), and AQ group (AQ Bond). Each adhesive was applied to cut enamel surface as per manufacturer's instruction. Light-cured (Filtek Z 250) or dual-cured composite (Luxacore) was bonded to enamel of each specimen using Tygon tube.

After storage in distilled water for 24 hours, the bonded specimens were subjected to µSBS testing with a crosshead speed of 1 mm/minute. The mean µSBS (n = 20 for each group) was statistically compared using two-way ANOVA, Tukey HSD, and t test at the 0.05 probability level. The results of this study were as follows;

1. The µSBS of light-cured composite was significantly higher than that of dual-cured composite when same adhesive was applied to enamel.

2. For Z 250, the µSBS of AQ group (9.95 ± 2.51 MPa) to enamel was significantly higher than that of Adper goup (6.74 ± 1.80 MPa), but not significantly different with Xeno group (7.73 ± 2.01 MPa).

3. For Luxacore, the µSBS of Xeno group (5.19 ± 1.32 MPa) to enamel was significantly higher than that of Adper goup (3.41 ± 1.19 MPa), but not significantly different with AQ group (4.50 ± 0.96 MPa).

The purpose of this study was to evaluate the abrasion resistance of surface penetrating sealant which was applied on a composite resin restoration and to provide proper time to reapply sealant on composite resin surface.

Two hundred rectangular specimens, sized 8 × 3 × 2 mm, were made of Micronew (Bisco, Inc., Schaumburg, IL, U.S.A) and divided into two groups; F group (n = 10) was finished with coarse and medium grit of Sof-Lex discs and BisCoverwas applied B group (n = 190) after finishing with discs. B group was again subdivided into nineteen subgroups. From B-1 group to B-18 group were subjected to toothbrush abrasion test using a distilled water-dentifrice slurry and toothbrush heads. B-IM group was not subjected to toothbrush abrasion test.

Average surface roughness (Ra) of each group was calculated using a surface roughness tester (Surfcorder MSE-1700: Kosaka Laboratory Ltd., Tokyo, Japan). A representative specimen of each group was examined by FE-SEM (S-4700: Hitachi High Technologies Co., Tokyo, Japan). The data were analysed using cluster analysis, paired t-test, and repeated measure ANOVA. The results of this study were as follows;

Ra of F group was 0.898 ± 0.145 μm and B-IM group was 0.289 ± 0.142 μm. Ra became higher from B-1 group (0.299 ± 0.48 μm) to B-18 group (0.642 ± 0.313 μm).

Within a limitation of this study, finished resin surface will be again smooth and glazy if BisCover would be reapplied within 8 to 14 months after applying to resin surface.

The purpose of this study was to compare the ability of three resin surface sealants to prevent microleakage in Class V composite resin restorations. Forty Class V cavities with the occlusal margin in enamel and gingival margin in dentin were prepared on the buccal surfaces of sound extracted molars, and restored with composite resin. Restorations were randomly assigned into one of four equal groups (n = 10): a control group, without resin sealing, and three experimental groups in which margins were sealed with Fortify Plus, Biscover and Permaseal, respectively. Specimens were thermocycled, immersed in a 2% methylene blue solution for 4 hours, sectioned longitudinally, and observed the leakage at the occlusal and gingival margins. The result was analyzed using Kruskal-Wallis test, Mann-Whitney test and Wilcoxon signed rank test.

In conclusion, the ability to reduce microleakage at occlusal margins was similar in all of three sealants. However at gingival margin, it depended on the type of used resin surface sealant. At gingival margin, control and Fortify Plus group showed statistically higher microleakage than PermaSeal group, and Fortify Plus group also showed higher microleakage than BisCover group (p < 0.05).

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.

The purpose of this study was to compare the effect on marginal leakage of a resin surface sealant (Biscover) applied before or after polymerization of composite resin to unsealed composite restorations. Thirty Class V cavities with the occlusal margin in enamel and cervical margin in dentin or cementum were prepared on the buccal surfaces of sound extracted molars and restored with a microfilled light-cured composite resin (Micronew). Restorations were randomly assigned into one of three equal groups (n = 10): a control group - no surface sealing, group 1 - applied Biscover after polymerization of the composite resin, and group 2 - applied Biscover before polymerization of the composite resin. Specimens were thermocycled, immersed in a 2% methylene blue solution for 4 hours, sectioned longitudinally, and analyzed for leakage at the occlusal and gingival margins. The results of this study were as follows;

1. In sealed group, group 2 showed higher microleakage than group 1 at both occlusal and gingival margins, but there was no significant difference between two groups (p > 0.05).

2. Unsealed control group showed a little higher microleakage than sealed group at occlusal margins, and a little higher or similar microleakage than sealed group at gingival margins (p > 0.05).

3. Control group and group 2 showed significantly less microleakage at the occlusal margins, but group 1 showed no significantly difference between microleakage at the occlusal and gingival margins.

This study compared the microshear bond strength (µSBS) to end and side of enamel rod bonded by four adhesives including two total etch adhesives and two self-etch adhesives.

Crown segments of extracted human molars were cut mesiodistally. The outer buccal or lingual surface was used as specimens cutting the ends of enamel rods, and inner slabs used as specimens cutting the sides of enamel rods.

They were assigned to four groups by used adhesives: Group 1 (All-Bond 2), Group 2 (Single Bond), Group 3 (Tyrian SPE/One-Step Plus), Group 4 (Adper Prompt L-Pop). After each adhesive was applied to enamel surface, three composite cylinders were adhered to it of each specimen using Tygon tube. After storage in distilled water for 24 hours, the bonded specimens were subjected to µSBS testing with a crosshead speed of 1 mm/minute. The results of this study were as follows;

1. The µSBS of Group 2 (16.50 ± 2.31 _MPa) and Group 4 (15.83 ± 2.33 _MPa) to the end of enamel prism was significantly higher than that of Group 1 (11.93 ± 2.25 _MPa) and Group 3 (11.97 ± 2.05 _MPa) (p < 0.05).

2. The µSBS of Group 2 (13.43 ± 2.93 _MPa) to the side of enamel prism was significantly higher than that of Group 1 (8.64 ± 1.53 _MPa), Group 3 (9.69 ± 1.80 _MPa), and Group 4 (10.56 ± 1.75 _MPa) (p < 0.05).

3. The mean µSBS to the end of enamel rod was significantly higher than that to the side of enamel rod in all group (p < 0.05).

This study compared the microtensile bond strength (µTBS) of single step adhesives to different dentin depths.

Superficial or deep dentin was exposed in 30 molar teeth by sectioning immediately under the DEJ or 1.5 mm area from central pit, respectively. After polishing with 600-grit SiC paper, the dentin surfaces were assigned to three groups: AQ group-AQ Bond, L-Pop group-Adper Prompt L-Pop, Xeno group-Xeno III.

The bonded specimens were sectioned into sticks and subjected to µTBS testing with a crosshead speed of 1 mm/minute. The results of this study were as follows;

The µTBS to superficial dentin was higher than that to deep dentin in all group.

The µTBS of Xeno group was significantly higher than that of L-Pop group and AQ group in both superficial and deep dentin (p < 0.05).

This study compared the microtensile bond strength (µTBS) of three single step adhesives to dentin.

Occlusal superficial dentin was exposed in fifteen human molars. They were assigned to three groups by used adhesives: Xeno group (Xeno III), Prompt group (Adper Prompt L-Pop), AQ group (AQ Bond).

Each adhesive was applied to dentin surface, and composite of same manufacturer was constructed. The bonded specimens were sectioned into sticks with an interface area approximately 1 mm², and subjected to µTBS testing with a crosshead speed of 1 mm/minute. The results of this study were as follows;

The µTBS to dentin was 48.78 ± 9.83 MPa for Xeno III, 30.22 ± 4.52 MPa for Adper Prompt L-Pop, and 26.31 ± 7.07 MPa for AQ Bond.

The mean µTBS of Xeno group was significantly higher than that of Prompt group and AQ group (p < 0.05).

There was no significant difference between the µTBS of Prompt group and AQ group.

This study compared the microtensile bond strength (μTBS) and microscopic change of two 2-step and two 1-step self-etching adhesives to dentin according to storage times in distilled water.

Occlusal dentin was exposed in 48 human molars. They were divided to four groups by different adhesives: SE Bond group (Clearfil SE Bond), AdheSE group (AdheSE), Adper group (Adper Prompt L-Pop), and Xeno group (Xeno III). Each group was stored in 37℃ distilled water for 1, 15, and 30 days.

Resin-bonded specimens were sectioned into beams and subjected to μTBS testing with a crosshead speed of 1 mm/minute. For SEM observation, one specimen was selected and sectioned in each group after each stroage time. Resin-dentin interface was observed under FE-SEM.

In all storage times, mean μTBS of SE group was significantly higher than those of other groups (p < 0.05). There was no significant difference between mean μTBS of SE group and AdheSE group among all storage times, but significant difference between 1- and 30-day storage in mean μTBS of Adper group and Xeno group (p < 0.05). For 1-and 15-day storage, all groups showed the close adaptation between resin-dentin interfaces. For 30-day storage, resin-dentin interfaces showed wide gap in Adper group and separate pattern in Xeno III group.

The purpose of this study was to evaluate the effect of immediate or delayed composite resin filling on dentinal microtensile bond strength (µTBS) after applied the adhesive.

The coronal dentin of human third molars was exposed. Single-Bond or One-Step was applied on the dentin surfaces, and composite resin were constructed immediately (group 1) or 5 min., 10 min., 15 min., 20 min. and 30 min. (groups 2-6) after an adhesive was applied. The specimens were sectioned and made bar-shaped. Each surface area of them was about 1mm². The µTBS test was performed by EZ test. The results were analysed by One-way ANOVA and Tukey's test at 95% significance level.

The results suggested that the µTBS of Single-Bond to dentin was decreased when the composite resin was constructed 20 min. and 30 min. after Single-Bond was applied. But the µTBS of One-Step was not affected by delayed composite resin filling.

This study evaluated the microleakage and interfacial gap between enamel and composite resin under the dry and wet condition of the enamel surface. V shaped class 5 cavities were prepared on the occlusal portion of extracted human molars. Samples were divided into three groups: D group (air dry for 10-15 s), BD group (blot dry with moist cotton pellet), and DR group (air dry for 10-15 s and rewet with Aqua-Prep F for 20 s).

Cavities were filled using Aelitefil composite resin after applied One-Step. Microleakage was tested by 2% methylene blue dye solution and the data were statistically analysed by Kruskal-Wallis test and Mann-Whitney test. Also Enamel-resin interface was observed under SEM. Group BD showed statistically lower microleakage than group D (p < 0.05), but there was no statistically significant difference between group BD and DR (p > 0.05). At the enamel-resin interface, group D showed the gap of 2 µm thickness, but group BD and DR showed close adaptation.

In conclusion, the use of blot dry and rewetting agent (Aqua-Prep F) resulted in decreased microleakage and improved adhesion between enamel and resin when using One-Step.

This study evaluated the marginal microleakage of five single step adhesives. Class V cavity preparations with occlusal margins in enamel and gingival margins in dentin were prepared on both buccal and lingual surfaces of extracted human molar teeth. Prepared teeth were randomly divided into five groups and restored using one of the single step adhesives and composite resins: Prompt L-Pop/Filtek Z-250 (Group 1), AQ Bond/Metafil CX (Group 2), One-Up Bond F/Palfique Toughwell (Group 3), Futurabond/Admira (Group 4), Xeno III/Spectrum TPH (Group 5).

The restored teeth were thermocycled. Microleakage was assessed by dye penetration using 2% methylene blue dye solution. The teeth were bisected buccolingually and evaluated for microleakage under steromicroscope. The data were statistically analysed by Kruskal-Wallis test and Mann-Whitney tests.

The results of this study were as follows;

Microleakage of enamel margins in group 3 was statistically higher than that in groups 1, 2, 4, 5 (p < 0.05).

In conclusion, Prompt L-Pop showed the least leakage at enamel margin, and AQ Bond showed at dentin margin in this study. Marginal miroleakage in dentin was higher than that in enamel.

This study investigated that the effect of rewetting agent on dentinal microtensile bond strength (µTBS). Human molars were sectioned to expose the superficial dentin surfaces.

Samples were divided into two groups according to type of adhesives-Single Bond (S) and One-Step (O)], and again subdivided into five groups by different dentin surface treatment-dry for 15s (D), blot dry (BD) or dry for 15s, and rewet with different rewetting agents [distilled water (DW), Gluma Desensitizer (GD) and Aqua-Prep (AP)] for 30s. After application of adhesive, composite resin was built up on the bonding surface. Each tooth was sectioned to obtain stick with 1 mm² cross sectional area and the µTBS was determined by EZ test.

In the S group, the mean µTBS of GD, AP and BD group was significantly higher than that of DW and D group (p < 0.05). In the O group, the mean µTBS of AP, GD, BD and DW group was significantly higher than that of D group (p < 0.05).

The data suggested that Gluma Desensitizer and Aqua-Prep could be successfully used as rewetting agents, and Distilled water could be acceptable in aceton based adhesive system only.