Effect of Arginine on Conversion of an Experimental Dental Adhesive

Objectives: The amino acid arginine has useful anti-caries properties due to the arginine deiminase pathway whereby the bacterial byproducts become less acidic. The addition of arginine to dental adhesives as an antibacterial agent is currently being investigated. The addition of arginine to an adhesive resin system must not diminish the chemical and mechanical properties for future clinical applications. Therefore, the objective of this study was to measure the degree of conversion (DC) and peak rate of conversion of the arginine-containing adhesive resin system.
Methods: Two types of adhesive (n=6 per group), one experimental with 7% arginine and the control were prepared and tested. Real time Raman spectroscopy was used to measure DC and peak rate of reaction while curing with an incident irradiance of 320mW/cm² at 320-500nm wavelength. Two-sample t-test was performed to evaluate the difference between the two adhesive types on DC and rate of polymerization (alpha=0.05).
Results: The mean DC of the arginine adhesive (73±2 %) was significantly higher than that observed in the control adhesive (70±2 %) (p=0.0105). There was no significant difference in peak rate of conversion between the two types of adhesive (arginine adhesive: 2.70±0.52 %/sec, control adhesive: 2.58±0.72 %/sec; p=0.7446).
Conclusions: The addition of 7% arginine to the experimental adhesive significantly increased the degree of conversion while not altering the rate of conversion.