Abstract
Introduction: This study tested the null hypothesis that there is no difference between the use of 1.3% NaOCl/17% ethylenediaminetetraacetic acid (EDTA) and 5.25% NaOCl/17% EDTA irrigation regimens on the collagen degradation and flexural strength reduction in mineralized dentin. Methods: Dentin powder and mineralized dentin sections were immersed in 1.3% or 5.25% NaOCl for 10-240 minutes and then rinsed with 17% EDTA as the final irrigant for 2 minutes. Untreated mineralized dentin powder/sections served as controls in the respective experiments. Dentin powders were examined by using Fourier transform infrared (FT-IR) spectroscopy to analyze their relative subsurface intact collagen content with the apatite/collagen ratio. Hydrated dentin sections were subjected to 3-point flexure under water for determining their flexural strengths. Results: Collagen degradation was significantly increased and the flexural strength of mineralized dentin was significantly reduced after the use of 5.25% NaOCl as the initial irrigant for more than 1 hour (P < .05). Conversely, changes were insignificant when 1.3% NaOCl was used as the initial irrigant for up to 4 hours (Kruskal-Wallis analysis of variance, n = 10, P < .05). Conclusions: The null hypothesis was rejected. The deleterious effects attributed to the use of NaOCl on dentin are concentration-dependent and time-dependent and are not associated with the demineralization caused by the use of EDTA as the final active irrigant.
Original language | English (US) |
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Pages (from-to) | 105-109 |
Number of pages | 5 |
Journal | Journal of endodontics |
Volume | 36 |
Issue number | 1 |
DOIs | |
State | Published - Jan 2010 |
Keywords
- Collagen
- Fourier transform infrared spectroscopy
- denaturation
- ethylenediamine tetraacetic acid
- flexural strength
- irrigation
- sodium hypochlorite
- three point bending
ASJC Scopus subject areas
- General Dentistry