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.