Studies on the Incorporation of Benzalkonium Chloride and Cetylpyridinium Chloride Antimicrobial Agents nto Glass-Ionomer Dental Cements

The effect of the antimicrobial additives benzalkonium chloride and cetylpyridinium chloride on a restorative glass-ionomer dental cement (Fuji IX) has been studied. Both substances were added to the glassionomer at levels of 1%, 2% and 3% by mass at the mixing stage, and various effects were studied. Setting time was altered in most cases, but only slightly. Compressive strength and release were both determined using cylindrical specimens of size 4 mm diameter x 6 mm height. Additives were found to reduce the compressive strength, but differences were not significant. Release was studied into 5 cm 3 volumes of deionised water, and determined by UV/visible spectrophotometery at a wavelength of 259 nm for CPC and 214 nm for BC. Data showed that release occurred by a diffusion mechanism for the first 2-3 hours, with diffusion coefficients varying with concentration. Values were in the range 1.97 x 10 -14 -1.78 x 10 -12 m 2 s -1 . Release had ceased after six weeks, with total release representing between 2.15 and 4.84% of the initial additive loading.