Background: The antibacterial activity of restorative material and the amount of fluoride released are interlinked. Hence, these are the two foremost properties to be studied. Aim: This study aimed to evaluate and compare the amount and pattern of fluoride release from Type IX GIC (GC HS posterior), nanoionomer (Ketac N100), and alkasite (Cention N), and the antibacterial activity against Streptococcus mutans at 24 and 48 h. Settings and Design: This in vitro study was carried out in laboratory settings with six samples of each group for fluoride release using an ion-chromatography (IC) machine and five samples of each group for antibacterial activity using agar plates. Materials and Methodology: Samples of each group, Group I – Type IX GIC, Group II – nanoionomer, and Group III –alkasite, were prepared, immersed in 2 ml of artificial saliva, and fluoride release recorded using IC after 1, 7, 14, and 28 days intervals. The antibacterial activity against S. mutans was evaluated by placing samples of each group in the agar plates and measuring the diameter of zones of inhibition after 24 and 48 h. Statistical Analysis: One-way ANOVA test to check to mean differences between the groups and Tukey's honestly significant difference post hoc test for multiple intergroup comparisons ( P = 0.05). Results: The Type IX GIC showed the highest fluoride release after day1. However, nanoionomer showed the maximum fluoride release for the remaining days. The least amount of fluoride released was from the alkasite throughout the study. The antibacterial activity of nanoionomer was the highest, followed by Type IX GIC and alkasite at both 24 and 48 h. Conclusions: Nanoionomer showed the highest fluoride release and antibacterial activity.

Aim: The purpose of the study was to evaluate and compare canal transportation (CT) and centering ability (CA) between sequential rotary, single rotary, and single reciprocating file systems using cone-beam computed tomography (CBCT) in simulated curved canals. Materials and Methods: Thirty curved root canals simulated in clear resin blocks were divided randomly into three groups – Group I – ProTaper Gold–PTG (Sequential continuous rotation), Group II – One Curve-OC (Single-file continuous rotation), and Group III – WaveOne GOLD-WOGs (Single-file reciprocating motion) Ten samples of each group were positioned in a custom-made dental stone holder and subjected to CBCT scanning with 5 samples at a time at 3 mm, 5 mm, and 7 mm from the apical end before and after instrumentation. The canals were subjected to instrumentation using the files according to the group allotted. The files were used as recommended by the manufacturer and subjected to CBCT scanning. The values of CT and CA were obtained using the formula given by Gambill et al., and statistical analysis was performed. Results: The results showed that within the groups, all groups showed higher mean values of CT and lower CA in apical level followed by middle and coronal level, respectively, and between the groups, the least CT and highest CA exhibited in WOG followed by OC and PTG, respectively. Conclusion: The least CT and highest CA exhibited in WOG (Single-file reciprocation system) followed by OC (Single-file continuous rotation) and PTG (Sequential file system with continuous rotation), respectively.