Scanning electron microscope study on the action of endodontic irrigants on bacteria invading the dentinal tubules

Three groups of 10 maxillary anterior teeth each, which had been exposed to oral media, were flushed with 9 ml of tap water, physiologic saline solution, and alternating irrigation with NaOCl and hydrogen peroxide respectively. Residual caries, necrotic tissue remnants, intertubular cavitation, and dentinal tubule invasion by bacteria were searched for by means of the scanning electron microscope. Cuboidal sodium chloride crystals were very frequently found deposited in the main root canal, in lateral canals, and inside the dentinal tubules. This study discusses the important role NaOCl may play as a solvent of dental plaque and necrotic tissue remnants in the clinical endodontic treatment of infected teeth that had been exposed to oral media.