(PR46) Assessment of the Antibacterial Efficacy of a Novel Root Canal Sealer Against a Multi-species Biofilm in the Human Root Dentine Using Confocal Laser Scanning Microscopy: An in-vitro Study

Abstract: Endodontic biofilms are polymicrobial and cannot be removed by chemo-mechanical preparation alone. Therefore, obturating materials with antibacterial activity is preferred. Calcium-silicate sealers like Endosequence BC-sealer have gained popularity in recent years. However, limited data exist regarding their effectiveness against multispecies biofilm. Recently, a new calcium-silicate sealer, NeoSEALER-Flo has been introduced. This invitro study aimed to evaluate and compare the anti-bacterial efficacy of NeoSEALER-Flo, BC-sealer and AH-Plus against a multi-species biofilm on human root dentine at 1, 7, and 30 days using Confocal laser scanning microscopy (CLSM). Sixty-six root dentin halves were prepared and sterilized. Specimens were inoculated with Enterococcus faecalis, Streptococcus anginosus and Actinomyces viscosus for 21 days to form a multispecies biofilm. Six specimens were used to ensure sterilization and biofilm formation. Remaining sixty specimens were randomly divided into four groups (n=15) based on the sealer used:AH-Plus, BC-sealer, Neosealer-Flo and no sealer (Control). At the end of each time interval, five specimens from each group were labeled with fluorescent dye and examined under CLSM to assess the proportion of dead bacteria. Statistical analysis was performed using two-way ANOVA and Kolmogorov-Smirnov test. All sealers killed significantly more bacteria than the control at all time intervals (ANOVA, p<0.05). The percentage of dead bacteria increased with time in BC-sealer and Neosealer-Flo group (60% and 63% respectively, at 30 days). The antibacterial activity of AH-Plus decreased over time. Bioceramic sealers exhibited superior antimicrobial properties against multispecies biofilm. Neosealer was as effective as the BC-sealer at all time intervals.