A Study on Organic Substance Dissolving Ability of 6% NaOCl Paste

Abstract

Abstract : The purpose of this study was to evaluate the organic substance dissolving ability of a viscous paste type NaOCl, which was made on an experimental basis.

 A 6% NaOCl paste was prepared by adding an inorganic compound thickener (montmorillonite) to NaOCl solution. A extracted third molar was used for the organic substance dissolving ability survey. The Tooth was cut horizontally at the pulp chamber level to obtain several slices, then the slices were devided to small pieces including the chamber wall by a nipper. Numerous tooth pieces were immersed in NaOCl paste for 5-60 minutes. A 6% NaOCl solution served as a control. After immersion, the specimens were dehydrated and coated with Pt-Pd. The pulp chamber wall of each specimen was observed by a scanning electron microscope.

 Five minutes after the start of immersion in this paste, most pulp remnants on the pulp chamber wall and the superficial layers of the predentin had dissolved. By 10 minutes, the calcospherite immediately below the predentin was partially exposed. By 15 minutes, the predentin was completely dissolved, resulting in full exposure of the calcospherite. The organic substance dissolving ability of the NaOCl paste was a little lower than that of thickener-free NaOCl solution. However, the NaOCl paste is very effective clinically due to the excellent manipulation during mechanical root canal preparation.