The influence of antibiotics on the physical properties of endodontic cements

Aim: To evaluate the influence of Metronidazole, Minocycline and Ciprofloxacin as a mixture or individually and of chlorhexidine on the push-out bond strength and surface microhardness of calcium silicate cements of differing particle size. Methodology: 120 extracted adult human premolars were decoronated and 2 mm dentin slices were prepared. Specimens were divided equally into the following groups: normal saline and CHX, Metronidazole, Minocycline, Ciprofloxacin, and combination of Metronidazole, Minocycline and Ciprofloxacin. The specimens were irrigated with solutions and filled with endodontic cements. In the second part, the endodontic cements were mixed, placed in plastic tubes and then irrigated for 1 or 5 min. Push-out and surface microhardness values were calculated and data were analyzed with three way ANOVA followed by Tukey’s post-hoc test. Results: The normal saline and ciprofloxacin groups showed significantly higher and lower, respectively, push-out bond strength among the experimental groups (p < 0.001 for all groups). Nano type cement showed higher push-out bond strength and microhardness than regular one at both time intervals. The mixture of antibiotics had significant effects on the push out and microhardness of calcium silicate cement. Conclusions: Nano particle MTA resisted more than the conventional MTA to the effect of the irrigating solution and antibiotics in both hardness and push-out strength. Furthermore, the results of microhardness were consistent with the push-out strength in most cases. The microhardness test may be employed as a complimentary test to evaluate push-out strength of dental cements.