Development and Evaluation of Bioactive Glass Ceramic-Based Endodontic Cement: A Comprehensive Study on Bioactivity, Biocompatibility, Mechanical Properties, Radiopacity, and Antimicrobial Activity

Endodontic cements play a crucial role in root canal treatment by sealing the canal and preventing reinfection. However, existing materials have limitations, including suboptimal bioactivity, handling properties, setting times, and antimicrobial efficacy. This study aimed to develop endodontic cements incorporating bismuth oxide, lanthanum oxide, and samarium oxide, and evaluate their physicochemical and biological properties according to the ISO 6876:2012(12) standard, FTIR, and SEM analyses confirmed the formation of a calcium phosphate apatite layer, indicating the bioactive potential of the cements for tissue regeneration. Rheological testing showed that cements containing glycerin (S1, S2) had improved flowability due to the viscosity-reducing properties of glycerin. Varying the water-to-powder ratios revealed that lower ratios resulted in reduced porosity and enhanced mechanical properties, with bismuth oxide being the most effective additive. Cements containing carboxymethyl cellulose (S3-S5) exhibited optimal flow values due to the dispersion-stabilizing effect of CMC. Antimicrobial evaluation demonstrated that the S2 group, with bismuth oxide, had the highest antibacterial activity (26.51 mm), followed by samarium oxide (24.19 mm) and lanthanum oxide (20.10 mm). Similar trends were observed for the S3 and S4 groups, with bismuth oxide exhibiting the greatest efficacy. Radiopacity analysis showed that all additives significantly increased the values, with bismuth oxide reaching the highest at 7.70 mm Al. Lanthanum oxide and samarium oxide also increased radiopacity to 6.21 mm Al and 7.53 mm Al, respectively. Biocompatibility assessment using human dental pulp stem cells revealed cell viability ranging from 73 to 105% after 1 day, exceeding the 70% biomedical threshold. The developed cements meet the requirements of current legislation and are considered suitable for endodontic applications.