Effects of EDTA, fumaric acid, and the chitosan solutions prepared with distilled water and acetic acid on dentin microhardness and tubular penetration: An in vitro study.

Abstract

Background: Chitosan prepared with acetic acid is commonly used as an endodontic irrigant. However, the chitosan solution prepared with distilled water has not been evaluated for endodontic usage.

Objectives: The present study aimed to compare the effects of ethylenediaminetetraacetic acid (EDTA), fumaric acid, and the chitosan solutions prepared with distilled water (C-DW) and acetic acid (C-AA) on dentin microhardness and dentinal tubule penetration.

Material and methods: Eighty maxillary central incisors were endodontically instrumented and randomly divided into 2 main groups (n = 40) for the evaluation of dentin microhardness and tubular penetration, with 4 subgroups in each main group (n = 10) according to the final irrigation solutions used (EDTA, fumaric acid, C-DW, and C-AA). The C-AA solution was prepared by diluting medium-molecularweight chitosan in acetic acid. The C-DW solution was prepared with distilled water and chitosan ammonium salts, which were synthesized using trichloroacetic acid and low-molecular-weight chitosan. After irrigation, the roots were sectioned horizontally 2 mm (the apical third) and 5 mm (the middle third) from the apex. The microhardness measurements were taken at depths of 500 μm and 1,000 μm from the canal lumen. The sections were examined for tubular penetration using confocal laser scanning microscopy. The data was analyzed using the analysis of variance (ANOVA), with a significance level set at p < 0.05.

Results: The microhardness values were statistically similar at either depth for each third (p > 0.05), except for the 1,000-μm depth in the apical third, where the use of the C-AA solution resulted in lower microhardness as compared to fumaric acid (p < 0.05). No significant differences were observed in tubular penetration with regard to each third (p > 0.05).

Conclusions: All solutions showed a similar penetration ability in each third. At the 1,000-μm depth in the apical third, the fumaric acid solution provided a higher microhardness value than the C-AA solution.