Physicochemical and Biological Properties of Plasticizing Agents in Bioceramic Sealers

Objectives: Calcium silicate-based sealers often exhibit a sandy consistency and require plasticizing agents, such as polymers, to improve handling and flow in the canal system. Various polymers may contribute differently to the physicochemical properties of these cements, and their effects need further investigation. This study aims to evaluate the impact of added plasticizers—such as propylene glycol (PG), polyethylene glycol 400 (PEG), polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), hydroxyethyl cellulose (HEC), and carboxymethyl cellulose (CMC)—on the physicochemical and biological properties of tricalcium silicate-based bioceramic sealers. BioRoot RCS (BR) was used as a control, and distilled water served as a negative control.
Methods: Physicochemical testing was conducted according to ISO 6876/2012 standards, evaluating setting time, flow, film thickness, radiopacity, solubility, and pH at 1, 7, 14, and 28 days. Chemical characterization was performed using RAMAN, FT-IR, and X-ray diffraction (XRD). The cell viability of plasticizers was assessed using the MTT assay in gingival fibroblasts. Antimicrobial activity was tested against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Candida albicans via the agar diffusion method. Data were analyzed using ANOVA and Tukey's test (p<0.05).
Results: Experimental cements showed a setting time of approximately one hour. BioRoot had the longest setting time, highest flow, and lowest film thickness (p<0.05). All cements exceeded the ISO standard flow of 17 mm. Radiopacity was 3 mmAl for all groups. PVA exhibited the lowest solubility (p<0.05). PVA, PEG, and PVP had over 80% cell viability, with PVA showing the highest value (p<0.05). No plasticizer showed antimicrobial activity.
Conclusions: PVA emerged as the most advantageous plasticizer for bioceramic sealers on its physicochemical properties and biocompatibility.