A self-etching adhesive exhibited significantly lower bond strength to dentin contaminated with 25% aluminum chloride solution compared to normal dentin, but a total-etching adhesive exhibited no difference in bond strength to either contaminated or normal dentin. Longer primer application of the self-etching adhesive significantly increased the dentin bond strength of the contaminated group. SUMMARYThis study evaluated the bond strength of a totaletch and a self-etch adhesive to dentin contaminated with a hemostatic agent containing aluminum chloride (AlCl 3 ). Eighteen occlusal dentin discs were prepared from human molars. Each disc was ground and sectioned into two halves, one for normal dentin and the other for contaminated dentin. The specimens of both normal and contaminated dentin were randomly divided into three groups and treated with the following materials: 1) Excite (EX); 2) Clearfil SE Bond with 20-second primer application time (CB 20) and 3) Clearfil SE Bond with 40-second primer application time (CB 40). The microshear bond strength specimens were prepared using the resin composite Clearfil APX. The bond strengths were evaluated on a universal testing machine. Statistical analysis was performed at α=0.05. The surface micromorphology and aluminum content of the different dentin conditions were also examined. In EX, no significant difference was found between the bond strengths of normal dentin and contaminated dentin. The bond strength of CB20 to contaminated dentin was significantly lower than that to normal dentin. The

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The purpose of this study was to evaluate the dynamic viscoelastic properties of experimental silicone soft lining materials, Silastic ® MDX 4-4210 reinforced with silica fillers. Storage modulus (E '), loss modulus (E ") and damping factor (tan δ) were determined using a dynamic mechanical analyzer under a deformation strain level of 0.27% at test frequency and a temperature range of 1 Hz and 0 to 60°C, respectively. The degree of silica dispersion was also studied using a field emission scanning electron microscopy (FE-SEM). One-way ANOVA and Tukey's HSD test results indicated that the prepared silicone elastomers provided a significantly greater damping factor, but less storage modulus than GC Reline Soft and Tokuyama Sofreliner Tough (p<0.001). The storage moduli, loss moduli and damping factor of the experimental silicone elastomers increased with increasing amounts of fumed silica. In conclusion, the experimental silicone elastomers revealed acceptable dynamic viscoelastic properties to be used as denture soft lining materials.

Despite an irregular surface morphology and absence of a smear layer, bonding to pulpal floor dentine was weaker than previously reported for cut coronal dentine. The self-etching-priming system bonded more strongly than the 'one-bottle' system.