Effect of Different Milk on Hydraulic Conductance of Human Dentin

Methods: 24 non-carious extracted human premolars were used. Each tooth was sectioned transversely below to the cemento-enamel junction 1-2 mm. Dentin was exposed at the tip of the buccal cusp of a premolar by cutting a cavity (diam. 3 mm, depth 3 mm). After coronal pulp removal, the sectioned tooth was glued to the plastic block which connected to manometer with polyethylene tube. The system was filled with normal saline solution and the hydraulic conductance was measured by following the movement of an air bubble in a capillary (int. dia. 300 µm). Each tooth was etched with 34% phosphoric acid for 30 s prior to the baseline measurement of hydraulic conductance. These teeth were randomly treated with different milk and finally treated with 3% potassium tetraoxalate. 

Results: All five treatments were able to reduce hydraulic conductance significantly. Hydraulic conductance reduction for cow milk, buffalo milk, soy milk, and high calcium milk were 7.642%, 15.331%, 6.842%, 14.021%, respectively. 3% potassium tetraoxalate was able to reduce hydraulic conductance up to 81.530%. Buffalo milk and high calcium milk can reduce the hydraulic conductance significantly greater than cow milk and soy milk (Friedman RM ANOVA, and Tukey test, P≤0.001).

Conclusions: It was concluded that all types of milk could reduce hydraulic conductance of dentin, which buffalo milk and high calcium milk had more effect.