Volumetric change of calcium silicate‑based repair materials in a simulated inflammatory environment: A micro‑computed tomography study

Context: An acidic hydrogen potential (pH) in an inflammatory condition in the periapical tissues may affect the properties of repair bioceramic cement. Aims: The aim of this study was to evaluate the effect of pH on the volumetric change of the ready‑to‑use bioceramic NeoPUTTY (NP) compared to the powder/liquid MTA Repair HP (MTAHP) after immersion in butyric acid (BA, pH 4.1) or phosphate‑buffered saline (PBS, pH 7.35). Subjects and Methods: Dentin tubes filled with NP or MTAHP were scanned in micro‑computed tomography (micro‑CT) after 24 h. Then, the specimens were immersed in 1.5 mL of BA: NP/BA, MTAHP/BA or PBS: NP/PBS, MTAHP/PBS. After 7 days, new micro‑CT scans were performed. The percentage of volumetric change (extremities and internal part) of the materials was assessed. Statistical Analysis Used: ANOVA/Tukey and Kruskal–Wallis tests were performed (α =0.05). Results: All materials showed a volumetric decrease after immersion in BA or PBS at the extremities in contact with the solutions. MTAHP/BA showed the highest volumetric loss. There was no difference in the volumetric change when the internal part of the materials was evaluated. Conclusions: An acid pH negatively affects the volumetric stability of MTAHP. Low values of volumetric change were demonstrated for NP in both immersion environments.