In vitro bioactivity of newly introduced dual‑cured resin‑modified calcium silicate cement

Abstract

Background: This study was designed to investigate the in vitro bioactivity of a new dual cured
calcium silicate cement (TheraCal PT) compared to its light cured (TheraCal LC) and chemically
set (Biodentine) counterparts.
Materials and Methods: The study is an in vitro original research article. Prepared cements
discs were immersed in deionized water. Ca2+ release was evaluated using inductively coupled
plasma‑optical emission spectrometry while pH was assessed using a pH meter after 1, 14, and
28 days. Discs for surface characterization were immersed in phosphate‑buffered saline (PBS)
and were examined using an environmental scanning electron microscope with energy dispersive
X‑ray (ESEM/EDX), immediately after setting and at 1, 14, and 28 days intervals after that. Attenuated
total reflectance (ATR)/Fourier transform infrared (FTIR) and Raman spectroscopy analyses were
performed after setting and after 28 days storage in PBS. Statistical analysis was performed using
the two‑way repeated measure analysis of variance test followed by Bonferroni test for multiple
comparisons (P < 0.05).
Results: Biodentine exhibited the highest mean values for Ca2+ release (792,639,278 ppm) and
pH (10.99, 12.7, 11.54) at all time intervals. ESEM/EDX displayed a continuous layer of calcium
phosphate formed by Biodentine and TheraCal LC while TheraCal PT developed scarce interrupted
precipitates after immersion in PBS. ATR/FTIR and Raman spectroscopy for the formed precipitates
confirmed the presence of phosphate and Ca (OH) 2 in Biodentine, TheraCal LC and TheraCal PT.
Conclusion: TheraCal PT exhibited limited in vitro bioactivity which may limit its prognosis in
clinical applications for vital pulp therapy. TheraCal LC is considered a potential bioactive calcium
silicate cement despite its lower Ca2+ release compared to Biodentine. Highest bioactivity was
observed in Biodentine.
Key Words: Calcium silicate, dental cements, dental pulp capping, hydrogen ion concentration,
pulpotomy