The outcome of periapical surgery has been directly improved with the introduction of novel material formulations. The aim of the study was to compare the retrograde obturation quality of the following materials: calcium silicate (Biodentine; Septodont, Saint-Maur-des-Fosses, France), mineral trioxide aggregate (MTA+; Cerkamed Company, Stalowa Wola, Poland), and glass ionomer cement (Fuji IX; GC Corporation, Tokyo, Japan).
Materials' wettability was calculated concerning the contact angles of the cements measured using a glycerol drop. Cements' porosity was determined using mercury intrusion porosimetry and micro-computed tomographic (μCT) imaging. Extracted upper human incisors were retrofilled, and μCT analysis was applied to calculate the volume of the gap between the retrograde filling material and root canal dentin. Experiments were performed before and after soaking the materials in simulated body fluid (SBF).
No statistically significant differences were found among the contact angles of the studied materials after being soaked in SBF. The material with the lowest nanoporosity (Fuji IX: 2.99% and 4.17% before and after SBF, respectively) showed the highest values of microporosity (4.2% and 3.1% before and after SBF, respectively). Biodentine had the lowest value of microporosity (1.2% and 0.8% before and after SBF, respectively) and the lowest value of microgap to the root canal wall ([10 ± 30] × 10-3 mm3).
Biodentine and MTA possess certain advantages over Fuji IX for hermetic obturation of retrograde root canals. Biodentine shows a tendency toward the lowest marginal gap at the cement-to-dentin interface.