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The common belief that simpler, speedier, more user-friendly adhesives always reduce technique sensitivity should be revaluated. Clinicians should resist the attraction of new, faster, easier-use materials and ask for laboratory and clinical studies before switching to a new material. SUMMARYThis study evaluated the efficacy of a total-etch and three self-etch adhesives in reducing microleakage after three months water storage and thermocycling.Thirty freshly extracted caries-free human premolars and molars were used. Class V standardized preparations were performed on the facial and lingual surfaces, with the gingival margin placed 1 mm below the CEJ. The teeth were randomly divided into four groups; Group I: Xeno III one-step self-etch adhesive (Dentsply/Caulk), Group II: Prime & Bond NT total-etch adhesive (Dentsply/Caulk), Group III: i-Bond one-step selfetch adhesive (Heraeus Kulzer) and Group IV: Clearfil SE Bond two-step self-etch adhesive (Kuraray Medical). The teeth were restored using 2 mm increments of shade A2 resin composite (Esthet-X, Dentsply/Caulk). Each layer was cured using the Spectrum 800 curing light (Dentsply/Caulk) for 20 seconds at 600mW/cm 2 . The teeth were stored in distilled water for 90 days. Samples were thermocycled 500x between 5°C and 55°C with a dwell time of 30 seconds, then placed in a 0.5% methylene blue dye solution for 24 hours at 37°C. Samples were sectioned longitudinally and evaluated for microleakage at the occlusal and gingival margins under a stereomicroscope at 20x magnification. Dye penetration was scored: 0=no penetration; 1=partial dye penetration along the occlusal or gingival wall; 2=dye penetration along the occlusal or gingival wall; 3=dye penetration to and along the axial wall.A Mann-Whitney test was used to demonstrate significantly more dye penetration in Group III than in the other groups at both the occlusal and gingival scores (p<0.0001). When comparing the

Nonvital tooth whitening is responsible for a significant change in color of endodontically stained teeth. Successful nonvital tooth-whitening therapy allows for conservative tooth preparation, preserving and reinforcing sound tooth structure. The proper use of modern adhesive systems along with resin composite restorations precludes the use of more extensive restorative treatment, delaying expensive crown and bridge procedures.

Microhybrid composite resin demonstrated excellent clinical performance in direct cuspal coverage at completion of a 30-month evaluation. CLINICAL SIGNIFICANCE In selected clinical situations, cuspal coverage direct posterior composite restorations may represent a valid alternative to conventional indirect restorations.