Intratubular decontamination ability and physicochemical properties of calcium hydroxide pastes

ObjectiveThis in vitro study compared the penetration, pH, calcium ion release, solubility, and intradentinal decontamination capacity of calcium hydroxide (CH) pastes with different vehicles and additives.Materials and methodsInfected standard bovine dentine contaminated with Enterococcus faecalis were treated with propolis extract, chlorhexidine, and camphorated paramonochlorophenol (CPMC) loaded in CH paste for the bacterial viability evaluation made by confocal laser scanning microscopy (CLSM) and microbiological culture. Beside this, 50 acrylic teeth were filled with the previously mentioned pastes to evaluate the pH and calcium ion release (pHmeter and atomic absorption spectrophotometer at time intervals of 7, 15, and 30days) and solubility (micro-computed tomographic imaging before and after 15days).ResultsAfter treatment, all samples decreased intra-dentinal contamination, specially, the CH paste with CPMC. There was no statistically significant difference between the groups when evaluating the intra-canal paste penetration. In the pH measurements, CH with distilled water showed the smallest pH values. Regardless the solubility percentage of the pastes, the paste of CH+PG presented the highest values.ConclusionThe vehicles and additives tested may increase CH antimicrobial effect, but with small differences. In general, all CH pastes tested here were effective in reducing Enterococcus faecalis and were similar in the penetration, pH, calcium ion release, and solubility of calcium hydroxide when compared to distilled water.Clinical relevanceThe use of calcium hydroxide pastes as intracanal medication with an aqueous or viscous vehicle, as propylene glycol, can be useful, since all formulations of the tested pastes resulted in great bacterial reduction inside root canals. (AU)