Morphological and chemical changes in dentin after using endodontic agents: Fourier transform Raman spectroscopy, energy-dispersive x-ray fluorescence spectrometry, and scanning electron microscopy study

Abstract

We examine the morphological and chemical changes in the pulp chamber dentin after using endodontic agents by scanning electron microscopy (SEM), Fourier transform Raman spectroscopy (FT-Raman), and micro energy-dispersive x-ray fluorescence spectrometry (μEDXRF). Thirty teeth were sectioned exposing the pulp chamber and divided by six groups (n=5): NT-no treatment; CHX-2% chlorhexidine; CHXE-2% chlorhexidine+17% EDTA; E-17% EDTA; SH5-5.25% NaOCl; SH5E-5.25% NaOCl+17% EDTA. The inorganic and organic content was analyzed by FT-Raman. μEDXRF examined calcium (Ca) and phosphorus (P) content as well as Ca/P ratio. Impressions of specimens were evaluated by SEM. Data were submitted to Kruskal-Wallis and Dunn tests (p<0.05). Differences were observed among groups for the 960 cm(-1) peak. Ca and P content differences were significant (SH5>NT=SH5E>CHX>E>CHXE). CHXE and E presented the highest Ca/P ratio values compared to the other groups (p<0.05). The SEM images in the EDTA-treated groups had the highest number of open tubules. Erosion in the tubules was observed in CHX and SH5E groups. Endodontic agents change the inorganic and organic content of pulp chamber dentin. NaOCl used alone, or in association with EDTA, was the most effective agent considering chemical and morphological approaches.

Real-time evaluation of two light delivery systems for photodynamic disinfection of Candida albicans biofilm in curved root canals

“…According to our results and to the lack of side effects added to the simplicity of the APDT, execution encourages further research since a 2- to 6-min application, employing the diffuser optical fiber, provides a significant microbial reduction without using chemical compounds that might change the tooth structural strength and promote microbial resistance [41]. To eradicate persistent microbial load from root canals, the alternatives are the following: use of chemical irrigation solution, which depending on contact/time and concentration may significantly alter the dental structure microhardeness, elastic modulus, and flexural strength or to use systemic antibiotics which may increase the threat of microbial resistance selection [6, 42–44].…”

Molecular and Structural Evaluation of Dentin Caries-Like Lesions Produced by Different Artificial Models

“…Data were collected using parameters of X-ray emission of Ca and P. The oxygen (O) and hydrogen (H) elements were used for chemical balance (7,24,25).…”

“…Spectral resolution was set at 4 cm −1 . Three spectra were collected by 100 scans for each area (25).…”

Impact of chemical agents for surface treatments on microhardness and flexural strength of root dentin

“…15 Although the application of the aforementioned agents or their associations can preserve or improve the adhesion of resin materials to radicular dentin, 3,4,5,6,7,16,17 changes in organic and mineral content caused by these chemicals 18 could negatively affect the physical properties of dentin, thus causing root fragility.…”

“…CHX is a cationic compound that has the ability to bind anionic molecules, such as the phosphates present in the hydroxyapatite structure. 18 Considering that phosphate is present in the calcium carbonate complex of dentin, CHX can induce changes in the Ca/P ratio, 18 which could explain the reduced values of microhardness in root dentin exposed to CHX.…”