Journal of Applied Polymer Science, Vol.122, No.4, 2542-2551, 2011
Preparation and Evaluation of an Antibacterial Dental Cement Containing Quaternary Ammonium Salts
A novel PQAS-containing antibacterial glass-ionomer cement has been developed. The functional QAS and their constructed PQAS were synthesized, characterized, and formulated into the light-cured cements. Compressive strength (CS) and bacterial (S. mutans and lactobacillus) viability were used to evaluate the mechanical strength and antibacterial activity of the cements. Flexural (FS) and diametral tensile strengths (DTS) were tested as well. Fuji II LC cement was used as control. The specimens were conditioned in distilled water at 37 degrees C for 24 h prior to testing. All the PQAS-containing cements showed a significant antibacterial activity, accompanying with an initial CS reduction. The effects of chain length, loading, and grafting ratio of the QAS were significant. Increasing chain length, loading, grafting ratio significantly enhanced antibacterial activity but reduced the initial CS of the formed cements. The antibacterial effect of the substitute chain lengths from free QAS seem more significant in water than those from their polymers (PQAS) after integrating to the cement. The experimental cement showed less CS reduction and higher antibacterial activity than Fuji II LC. The long-term aging study indicates that the cement might have a long-lasting antibacterial function with no PQAS leaching. Within the limitations of this study, it appears that the experimental cement is a clinically attractive dental restorative that can be potentially used for long-lasting restorations due to its high mechanical strength and long-lasting antibacterial function. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 122: 2542-2551, 2011
Keywords:PQAS;substitute chain length;antibacterial;S. mutans viability;glass-ionomer cement;CS;aging