Effects of different radio-opacifying agents on physicochemical and biological properties of a novel root-end filling material

Abstract

Background/PurposeRadio-opacity is an essential attribute of ideal root-end filling materials because it is important for clinicians to observe root canal filling and to facilitate the follow-up instructions. The novel root-end filling material (NRFM) has good cytocompatibility and physicochemical properties but low intrinsic radio-opacity value. To improve its radio-opacity value, three novel radio-opaque root-end filling materials (NRRFMs) were developed by adding barium sulphate (NRFM-Ba), bismuth trioxide (NRFM-Bi) and zirconium dioxide (NRFM-Zr) to NRFM, respectively. The purpose of this study was to identify the suitable radio-opacifier for NRFM through evaluating their physicochemical and biological properties, in comparison with NRFM and glass ionomer cement (GIC).MethodsNRRFMs were characterized using X-ray diffraction (XRD) and Fourier transform infrared spectrophotometry (FTIR). Physicochemical properties including setting time, compressive strength, porosity, pH variation, solubility, washout resistance, contact angle and radiopacity were investigated. Cytocompatibility of both freshly mixed and set NRRFMs was investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Alkaline phosphatase (ALP) activity assay and alizarin red staining were used to investigate the osteogenic differentiation potential of NRFM-Zr. Data were analyzed using two-way ANOVA (pH variation, solubility and ALP activity) and one-way ANOVA (for the other variables).Results(1) NRRFMs were primarily composed of hydroxyapatite, calcium carboxylate salt and the corresponding radio-opacity agents (barium sulphate, bismuth trioxide or zirconium dioxide). (2) Besides similar physicochemical properties in terms of setting time, pH variation, solubility, washout resistance and contact angle to NRFM, NRFM-Bi and NRFM-Zr exhibited lower porosity and greater compressive strength after being set for 7 days and their radio-opacity were greater than the 3 mm aluminium thickness specified in ISO 6876 (2001). (3) MTT assay revealed that freshly mixed and set NRFM-Zr presented better cell viability than NRFM-Ba and NRFM-Bi at 24 hours and 48 hours (P<0.05). (4) NRFM-Zr significantly enhanced ALP activity and calcium formation of human osteoblast-like Saos-2 cells when compared with negative group and GIC (P<0.05).ConclusionNRFM-Zr presents desirable physicochemical and biological properties, thus zirconium dioxide may be a suitable radio-opacifier for NRFM.

Analysis of pH and cytotoxic activity of locally produced radiopaque white Portland cement

“…This finding is in accordance to one recent study performed on a novel root-end filling material. [23] but in contrast to another study. [24] which could be attributed to different materials used and methodological procedures for measuring the pH values.…”

A premixed magnesium phosphate-based sealer with anti-biofilm ability for root canal filling

“…[36][37][38] In addition, studies have shown that ZrO 2 is more biocompatible than Bi 2 O 3 and BaSO 4 . 39 Therefore, ZrO 2 was chosen as a radiopacity agent in the present study and the sealer 20%MgO/TMP was chosen in tests which need the addition of ZrO 2 due to its high antibacterial rate and physicochemical properties and then the radiopacity was tested, and physicochemical properties, antibacterial properties and cytotoxicity of the sealer with ZrO 2 incorporation were evaluated. It was reported that materials with the addition of 20% ZrO 2 could present higher radiopacity values than those of bone or dentin.…”

Radiopacidad de Cementos de Resina Compuesta Evaluados con Técnica Radiográfica Digital

“…Por ello, es relevante considerar la biocompatibilidad de los agentes radiopacos que se agregan y que podrían ser liberados con el tiempo. Con respecto óxidos de agentes radiopacos, como el de bario, se ha cuestionado su biocompatibilidad, a diferencia de otros agentes radiopacos, como el zirconio que es considerado químicamente inerte y biocompatible (22,23) .…”