Analyses of Experimental Injectable Bioactive Glass as an Endodontic Sealer

Objectives: This study aimed to synthesize fluoride-doped bioactive glass (F-BG) based thermo-responsive injectable hydrogel for endodontic applications.
Methods: The cold preparation method was used with F-BG, copolymer, and hydroxyl propyl methylcellulose. The structural and phase analyses were done with Fourier Transform Infrared Spectroscopy and X-ray Diffraction, respectively. The setting time of the prepared injectable was investigated at 21°C (in the presence and absence of an ultrasonic scalar) and at 37°C. Flowability was tested according to ISO-6876:2012 specifications, whereby injectability was checked by extrusion method using 21-, 22-, and 23-gauge needles. The in vitro bio-adhesion and push-out bond strength were studied on days 7 and 90 and compared with the commercially available TotalFill®. The ion release profile was analyzed for up to 30 days with inductively coupled plasma optical emission spectroscopy. Statistical analyses were performed using SPSS version 22 with one-way ANOVA post hoc tukey's test.
Results: The structural and phase analyses confirmed the presence of bioactive glass. The final setting time at 21°C, 21°C+ultrasonic scalar, and 37°C were 38.66±3.21, 29.12±1.23, and 32±3.46 min, respectively. The flowability was 25±3.94 mm, and the injectability coefficient was ≥70.3 for 22, 21, and 57% in a 23-gauge needle. A significant difference in bond strength was found between days 7 and 90, where the strength was increased, and a new apatite layer was formed on the tooth surface. Calcium, phosphate, and silicon were released more initially; however, continuous release was found for up to 30 days.
Conclusions: The prepared F-BG injectable hydrogel has shown promising results and has the potential to be used as an endodontic sealer.