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Background and Objective: Microleakage is one of the most important causes of failure in restoration and secondary caries. This study was conducted in order to compare dentinal microleakage of class II composite restorations using Universal Dental Adhesive, with and without liner. Methods: In this laboratory study, two Class II cavities were prepared in the mesial and distal surfaces of 48 healthy premolar teeth. Then, the samples were divided into 6 groups of 8 according to the application method of Single Bond Universal adhesive and liner: selective etching of enamel (SEE), self-etch (SE) technique, SEE technique and resin-modified glass-ionomer (RMGI) liner, SE technique and RMGI Liner, SEE technique and Flow Liner, and SE technique and Flow Liner. Restoration was done with Filtek Z250 composite. Microleakage was evaluated and compared using 2% fuchsine based on intensity 0 to 3. Findings: In the SEE group, 56.2% of restorations did not have microleakage. 31.2% had grade 3 microleakage and 12.5% had grade 1 microleakage. However, in the SEE+RMGI group, 81.25% and the SEE+Flow group, 81.2% of the restorations had no microleakage. In the SE group, 18.7% of restorations showed zero microleakage, 50% showed grade 3 microleakage, and 31.2% showed grade 2 microleakage. However, in the SE+RMGI group, 81.25% and in the SE+Flow group, 93.7% of the restorations did not have microleakage. The distribution of dentinal microleakage intensity between SEE and SE methods (p=0.067) and between SEE+RMGI and SEE+Flow groups (p=0.194) was not significant. However, in the SE+Flow and SE+RMGI groups, this difference was significant (p

Background and purpose: Microleakage is the most common cause of secondary caries and failure of restorations. The aim of this study was to evaluate the Microleakage between resin modified glass-ionomer (RMGI) and resin composite in sandwich restorations using different bonding agents. Materials and methods: Forty four premolars were used in this experimental study. Class II cavities were prepared and the gingival margin placed 1 mm below cementoenamel junction. RMGI (Fuji II LC) was inserted on the gingival floor in 1 mm thickness and the teeth were divided into two groups. Group I: cavities were etched, rinsed and treated with a total etch adhesive (Adper single bond 2). Group II: An universal adhesive (Single bond universal) was applied in self etch mode. All cavities were then restored incrementally using resin composite (Filtek Z 250). To evaluate the microleakage, the samples were subjected to thermocycling (3000 cycles), immersed in methylene blue for 72 hours, and sectioned mesiodistally. The samples were subsequently observed under stereomicroscope. Mann-Whitney test was used to analyze the data (P

Background and Aims: The purpose of this experimental study was to investigate the shear bond strength of three new adhesive systems to enamel and dentin of permanent human teeth using three new etch and rinse and self-etch adhesive systems.Materials and Methods: Sixty intact caries-free third molars were selected and randomly divided into 6 groups. Flat buccal and lingual enamel and dentin surfaces were prepared and mounted in the acrylic resin perpendicular to the plan of the horizon. Adhesives used in this study were Tetric N-Bond, AdheSE and AdheSE-One F (Ivoclar/Vivadent, Schaan, Liechtenstein). The adhesives were applied on the surfaces and cured with quartz tungsten halogen curing unit (600 mW/cm2 intensity) for 20 s. After attaching composite to the surfaces and thermocycling (500 cycles, 5-55ºC), shear bond strength was measured using a universal testing machine at a crosshead speed of 0.5 mm/min. The failure modes were examined under a stereomicroscope. The data were statistically analyzed using T-test, one-way ANOVA, Tukey and Fisher's exact tests.Results: In enamel, Tetric N-Bond (28.57±4.58 MPa) and AdheSE (21.97±7.6 MPa) had significantly higher bond strength than AdheSE-One F (7.16±2.09 MPa) (P0.05).Conclusion: Shear bond strength to dentin in Tetric N-Bond (etch and rinse system( was higher than self-etch adhesives (AdheSE and AdheSE-One F). The bond strength to enamel and dentin in two-step self-etch (AdheSE) was higher than one-step self-etch (AdheSE-One F).

Background and Aims: The purpose of this experimental study was to investigate the shear bond strength of three new adhesive systems to enamel and dentin of permanent human teeth using three new etch and rinse and self-etch adhesive systems. Materials and Methods: Sixty intact caries-free third molars were selected and randomly divided into 6 groups. Flat buccal and lingual enamel and dentin surfaces were prepared and mounted in the acrylic resin perpendicular to the plan of the horizon. Adhesives used in this study were Tetric N-Bond, AdheSE and AdheSE-One F (Ivoclar/Vivadent, Schaan, Liechtenstein). The adhesives were applied on the surfaces and cured with quartz tungsten halogen curing unit (600 mW/cm2 intensity) for 20 S. After attaching composite to the surfaces and thermocycling (500 cycles, 5-55?C), shear bond strength was measured using a universal testing machine at a crosshead speed of 0.5 mm/min. The failure modes were examined under a stereomicroscope. The data were statistically analyzed using t-test, one-way ANOVA, Tukey and Fisher's exact tests. Results: In enamel, Tetric N-Bond (28.57±4.58 MPa) and AdheSE (21.97±7.6 MPa) had significantly higher bond strength than AdheSE-One F (7.16±2.09 MPa) (P<0.0001). Tetric N-Bond had higher bond strength than AdheSE but there was not any significant differences between them (P=0.093). In dentin, there were significantly differences among all adhesives (P<0.001). Tetric N-Bond (20.62±3.03 MPa) showed the highest and AdheSEOne F (6.54±1.13 MPa) had the lowest value. The bond strength in enamel was higher than that observed in dentin and the difference was significant in Tetric N-Bond (P=0.044) and AdheSE (P=0.000) groups. There were no significant differences in the mode of failures among groups (P>0.05). Conclusion: Shear bond strength to dentin in Tetric N-Bond (etch and rinse system) was higher than self-etch adhesives (AdheSE and AdheSE-One F). The bond strength to enamel and dentin in two-step self-etch (AdheSE) was higher than one-step self-etch (AdheSE-One F) [ABSTRACT FROM AUTHOR]