الفهرس 
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Abstract
Objectives: To investigate the effect of MDPB antibacterial monomer and fluoride on microshear bond strength (µSBS) to dentin and antibacterial effect on Streptococcus mutans cariogenic bacteria (S mutans) of self-etch adhesives. Materials and Methods: thirty-six extracted healthy human caries-free third molars were ground occlusally to expose the dentin, and then randomly divided into three equal groups of 12 molars for each. For each group 10 molars were used for microshear bond strength (μSBS), while 2 molars were used for nanoleakage evaluation by scanning electron microscope (SEM), three two-step self-etch adhesives were selected for the current study (Clearfil SE Bond, Clearfil liner Bond F and Clearfil SE Protect Bond) and used in accordance with manufacturer’s instructions. After, application of the adhesive systems, rods of nanohybrid resin composite (Filtek Z-350 XT, 3M ESPE) were built up on the dentin surface and then were prepared for μSBS testing, the rods were mechanically fixed to the μSBS testing apparatus. The bonding interface was stressed in microshear at a crosshead speed of one/mm/min until failure occurred. Resin-dentin interfaces produced by each system were examined by using SEM. The antibacterial activity of the bonding systems were evaluated using agar disc diffusion test. After obtain the S. mutans prepared three tryptic soy blood agar culture plates one for each type of bonding systems. Bacteria suspension was poured onto each agar plate Then, 20 μL from each type of bonding systems (10μL bond and 10μL primer) were applied on the top and bottom of a sterile paper disc with a (diameter of 6 mm and a thickness of 1.5 mm) 5μL on each side by the pipet. The paper discs saturated by the bonding systems were placed on the surface of the agar plates with cariogenic S. mutans and the plates were placed in autoclave to incubate anaerobically for 48 hours at 37°C. After that the growth inhibition zone was measured in millimeters. The collected data for both tests were statistically analyzed by using One-way analysis of variance (ANOVA) followed by post-hoc Tukey. Results: Statistically significant difference was there between the µSBS of the adhesive systems. A statistically significant difference was found between inhibition zones of S. mutans cultivated with different bonding system (p < 0.05). Clearfil Protect Bond exhibited significant inhibition zones compered to adhesives used against the S. mutans. Conclusions: Composition of self-etch adhesives regarding fluoride and MDPB affects the microshear bond strength to dentin and inhibit growth of S. mutans.