Short-term Effect of Four Root Filling Materials on the Flexural Strength of Human Root Dentin

Background: This study aimed to assess the effects of calcium hydroxide, Biodentine, calcium-enriched mixture (CEM) cement, and mineral trioxide aggregate (MTA) on root dentin flexural strength after a 30-day exposure period. Methods: This in vitro experimental study evaluated 25 freshly extracted sound human incisors with no caries or restorations. The apical 5 mm and the coronal two-thirds of the crowns were cut such that all samples had 10 mm length. Dentin samples (n=20 in each group) were then exposed to 2 mm thickness of calcium hydroxide, Biodentine, CEM cement, MTA, or saline (control) in petri dishes for 30 days. Finally, dentin samples were subjected to a three-point bending test after the intervention, and the flexural strength data were analyzed using one-way ANOVA, Tukey’s test, and t test. Results: Thirty-day exposure to all four biomaterials decreased the flexural strength of root dentin (P 0.05). The four groups were significantly different in terms of the flexural strength of root dentin (P = 0.001). The flexural strength of root dentin was significantly lower following exposure to calcium hydroxide (P = 0.003), Biodentine (P = 0.011), CEM cement (P = 0.001), and MTA (P = 0.007) compared to saline. The reduction in strength following exposure to calcium hydroxide was higher than that in Biodentine, CEM cement, and MTA groups (P 0.05) while the latter three were not significantly different in this respect (P 0.05). Conclusions: In general, all four tested biomaterials decrease the dentin strength although this reduction is more prominent by calcium hydroxide.