Physical Property Effect of Antimicrobial Additive in Light-cured Resin Cement

Objective:

To determine the effect of addition of a novel quaternary ammonium, methacrylate-functionalized silicate (QAMS) antimicrobial agent on selected physical and mechanical properties of a commercial light-cured dental resin cement.

Method:

A sol/gel process was used to fabricate a molecule based on a 1:1:3 molar ratio of tetraethoxysilane (TEOS), AEM5772 (a quaternary ammonium silane), and 3-methacryloxypropyltrimethoxysilane (3-MPTS), by mixing with water (pH 1) to cause 50% hydrolysis. The reaction product was incorporated into triethyleneglycol dimethacrylate, where further compounding resulted in a final QAMS concentration of 3 wt% in a commercially available, light-cured dental resin cement (CHOICE2, BISCO). Disc-shaped specimens of the material with and without QAMS (control) content were light-cured under similar conditions, and subjected to a variety of mechanical and physical property testing: monomer conversion and volumetric polymerization shrinkage 10-minutes following 60-s light exposure; biaxial flexural strength and Knoop hardness tested after 7-days storage in air or water (37°C). (N=5) Conversion and shrinkage data were compared using Student's T-test. Biaxial strength and Knoop hardness were analyzed using 2-way ANOVAs, with Tukey's post-hoc tests. A pre-set alpha of 0.05 was applied throughout.

Result:

Table shows mean (sd) parameter values

Within a test parameter, values having similar letters (upper case, column; lower case, row) were not significantly different. QAMS addition resulted in slightly lower monomer conversion and much lower polymerization shrinkage. Flexural strength was decreased with QAMS addition in dry or wet conditions, but strength of water stored QAMS-containing product was not affected compared to the dry. QAMS addition had no significant effect on hardness and was not affected by water-storage, although hardness of the control decreased in water.

Conclusion:

Addition of a silicate-based quaternary ammonium antimicrobial to a commercial light-curable resin-based dental cement resulted in slight decrease in some properties, but either did not alter or significantly enhanced others.