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 $960cm−1$ 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.

This study evaluated the structural and morphological differences between human and bovine primary root canals. Primary human maxillary central incisors (H) (n=9) and primary bovine incisors (B) (n=9) were selected. The roots were sectioned in the vestibular-lingual direction, planed and delimited in cervical, middle, and apical thirds. Tubule density (number of tubules per mm²) and diameter were analyzed by scanning electron microscopy (1,000 and 5,000×) using Image J 1.47 software. Data were submitted to two-way repeated measures ANOVA and Tukey tests (α=0.05). The highest tubule density was observed for B (28.527±1.717 mm²) compared with H (15.931±0.170 mm²) (p<0.01). Regarding root thirds, the cervical third presented a greater tubule density (26.417±11.654 mm²) than the apical third (17.999±5.873 mm²). The diameter of the dentin tubules was not different for cervical (3.50±0.08 µm), middle (3.45±0.30 µm) and apical thirds (3.42±0.33 µm) and substrate (H—3.29±0.14 µm; B—3.63±0.06 µm). It could be concluded that: (1) the radicular dentin structure of human and bovine primary teeth and root thirds differ in terms of the tubule density; (2) the radicular dentin morphology of human and bovine primary teeth and root thirds are similar in terms of the diameter of the dentin tubules.