Mucoprotein Affects Bond Strength of Composites to Human Dentin

Purpose: Bond strengths and morphology of the dentin-adhesive interface of several adhesive systems with two kinds of artificial saliva contamination under different conditions of decontaminating the interface were determined. Materials and Methods: Ninety-six human third molars were ground to expose superficial dentin and were bonded for a control and each of 3 contaminated conditions: 1. 10µL of saliva on the dentin surface mixed with the different adhesive systems (S); 2. 10µL of saliva on the dentin surface and air dried followed by the application of the different adhesive systems (SA); and 3. 10µL of saliva on the dentin surface, rinsed with water and air dried followed by the application of the different adhesive systems (SW) using artificial saliva with or without mucin. The adhesives/composites used were: Prime&Bond NT/TPH Spectrum, Adper Single Bond Plus /Filtek Supreme, SE Bond/APX, S³/APX. Bonded specimens were stored in water for 24 hours at 37 °C, sectioned perpendicularly to form bonded interfaces with 1-mm² areas, and then debonded in tension (Instron) at a cross-head speed of 0.5 mm/min. Tensile bond strengths were measured and analyzed by three-way ANOVA. Failure modes were determined using a microscope at 100x magnification. E-SEM micrographs were taken to analyze the dentin/adhesive interface. Results: ANOVA showed significant differences between the variables and Fisher PLSD intervals of comparison for saliva, adhesives, and conditions were 1.6, 2.3 and 2.3 MPa, respectively

Conclusion: This artificial saliva model showed that mucin could either increase or decrease the bond strength among different bonding agents and contamination conditions. Acknowledgement: Kuraray, 3M/ESPE, Denstply/Caulk, NIH/NIDCR T32 DE07236.