Erosivity Potential Method Development

Objective: To assess the erosive potential of commercially available mouthrinses with a pH level 5.5 or lower. Method: In part I, a HaP solution was prepared to represent human tooth enamel. Mouthrinses and buffers were added to the HaP solution. Then, the initial pH and final pH were recorded. Changes in pH determined the effects of mouthrinses on tooth enamel. Large changes in pH correspond to a high erosivity potential. In part II, titrations were performed in which 50 mL of solution (commercially available mouthrinses and citric acid buffers control) were titrated against a 0.1N NaOH solution. Results: In part I, pH recordings showed that the HaP solution, upon the addition of Listerine® mouthrinses, changed an average of -0.69 units from its initial pH reading. The 1% citric acid control buffer with initial pH of 2.54 caused the HaP solution's final pH to drop -1.59 units from its original pH reading. In part II, approximately 8.0272 mL of 0.1N NaOH was required from the Listerine® mouthrinses tested in order to achieve a target pH of 6.0. The 1% citric acid control buffer (pH 2.54) required 122.102 mL of 0.1N NaOH to reach a target pH of 6.0. Conclusion: The 1% citric acid control buffer's change in pH is approximately twice than that of Listerine® mouthrinses investigated in this experiment. The titratable acidity of the 1% citric acid control buffer (pH 2.54) was 10 times higher than the Listerine® mouthrinses tested. The 1% citric acid buffer (pH 2.54), was approximately 5 times higher than the other mouthrinses analyzed. The Listerine® brands assessed using this method were shown to have negligible effect on human enamel.