The purpose of this study was to determine whether four different treatments on wet or dry teeth, on the buccal and occlusal surfaces, affected the shear bond strength. The surface treatments consisted of a dentin conditioner (pH = 4.0), 10% phosphoric acid (pH = 1.6), 2.5 % nitric acid (pH = 1.0), and 2.5 % citric acid (pH = 1.0). One dentin bonding system and one dental composite was used for all of the specimens. The teeth were mounted in acrylic, ground and etched with the appropriate agent for 15 seconds. The dentin adhesive and composite were applied and the completed specimens stored for 24 hours before testing in either air or distilled water at room temperature. Testing was in shear using a guillotine device at a loading rate of 2 mm/min.
No statistical difference was found for the bond strength between the different dentin treatments on dry teeth. For wet teeth, phosphoric or nitric acid etching resulted in a significantly higher bond strength than treatment with citric acid or dentin conditioner. For the wet occlusal surface versus the wet buccal surface, phosphoric or nitric acid treatments, also resulted in a significantly higher bond strength than treatment with citric acid or dentin conditioner. The bond strength on wet teeth was significantly higher than on dry teeth for all surface treatments.
Drummond, James L.; Racean, D.; Van Scoyoc, J.; and Steinberg, A.
"Effect of Surface Treatments on Dentin Bonding Shear Strength,"
Cells and Materials: Vol. 2
, Article 6.
Available at: http://digitalcommons.usu.edu/cellsandmaterials/vol2/iss3/6