Heating stability, physical and chemical analysis of calcium silicate‐based endodontic sealers

Abstract

Aim To evaluate possible modifications in root canal sealers subjected to a variety of heating conditions using vibrational spectroscopy and analysis of physical and chemical properties. Methodology EndoSequence BC Sealer HiFlow, Bio‐C Sealer, BioRoot RCS and AH Plus were analysed chemically using Raman spectroscopy (25–220 °C) and Fourier‐transform infrared spectroscopy (FT‐IR) (37–100 °C ). For FT‐IR, the materials were tested individually and mixed with root dentine powder. Scanning electron microscopy (SEM) and coupled energy dispersive spectroscopy (EDS) were used to evaluate surface and chemical elements. ISO 6876‐2012 and ASTM‐C266‐07 specifications were followed to evaluate flow, setting time (moist and dry), solubility and radiopacity. Also, pH analysis at 37 and 100 °C was performed. Shapiro–Wilk and Mixed ANOVA (within and between the effects of the subjects), Levene, and a post hoc analyses with Bonferroni correction were performed (P < 0.05). Results Vibrational spectroscopy revealed peaks of tricalcium silicate, dicalcium silicate and zirconium dioxide. Chemical changes in the Raman spectra during heating were discrete, as the inorganic content predominated the signalling for all root canal sealers. FT‐IR analysis exhibited spectral changes in water absorption for EndoSequence BC Sealer HiFlow and Bio‐C Sealer, probably related to dehydration. For BioRoot RCS and AH Plus, no significant chemical changes were observed. Bio‐C Sealer exhibited a band of polyethylene glycol only after heating to 100 °C, probably related to its thermal decomposition. SEM/EDS analysis corroborated the composition results observed in vibrational spectroscopy for all materials. Heating to 100 °C significantly changed the flowability of all calcium silicate‐based sealers with a wide variation in setting times at both temperatures, along with solubility levels above ISO standards. For all tested sealers, radiopacity fulfilled the requirements, and pH exhibited alkaline values. Conclusions The tested calcium silicate‐based sealers were affected by heating. Calcium silicate‐based root canal sealers had high solubility which is a concern for their clinical use. AH Plus was the only root canal sealer that was stable after heating.

Radiopacity of Premixed calcium silicate-based endodontic sealers

“…This could be explained by the differences related to radiographic technologies used in previous studies. Studies that reported higher radiopacity values, as ours, used digital radiographic imaging systems, while studies that presented lower values for EndoSequence BC Sealer used conventional x-ray film for radiographic imaging 22,4 . It was suggested that this difference possibly could be a consequence of the material's composition and greater sensitivity of the digital sensors to high-energy photons 10,13 .…”

“…To može biti objašnjeno razlikama među radiografskim tehnikama korišćenim u ranijim studijama. U istraživanjima u kojima su dobijene više vrednosti rendgenkontrastnosti korišćeni su, kao i u našem istraživanju, digitalni radiografski sistemi, dok su u istraživanjima u kojima su dobijene niže vrednosti za EndoSequence BC Sealer korišćeni konvencionalni filmovi za radiografisanje 22,4 . Pretpostavlja se da ova razlika verovatno može biti posledica sastava materijala i veće osetljivosti digitalnih senzora na fotone visokih energija 10,13 .…”

Comparison of Root Filling Quality of Two Types of Single Cone-Based Canal Filling Methods in Complex Root Canal Anatomies: The Ultrasonic Vibration and Thermo-Hydrodynamic Obturation versus Single-Cone Technique

“…Even with the overall group results, we cannot rule out the possibility that the difference in the results between the VG and SE groups stems from differences in the properties of the materials, not from differences in the techniques. Furthermore, we selected Endoseal TCS as the only calcium silicate-based root canal sealer for this investigation, but there are currently various products of this kind with different physical properties [33]. Finally, some uncontrolled experimental elements, such as root canal configuration, length and volume, and the amount of root canal sealer, cannot be overlooked.…”

Volume Percentage of Filling Voids in Root Canals Prepared by a Novel Nickel-Titanium Rotary System (TruNatomy) Using Two Different Obturation Techniques

“…Since the CW method contains heat application, a calcium silicate–based sealer was not used for this CW group due to a possible adverse effect of heat. Previous studies have reported that heat could affect calcium silicate–based sealers’ chemical and physical properties [ 19 , 20 ]. CeraSeal used in the SC group is one of the calcium silicate–based sealers designed for SC filling; however, the effects of heat application on the physical and chemical properties of the sealer have not been reported.…”