Comparative Analysis of Fracture Resistance of Endodontic Sealer Types and Filling Methods

With the advent of bioceramic sealers, sealers have become a more important filling material for endodontic treatment. When a solid sealer, rather than an elastic gutta-percha, occupies a significant portion of the root canal, it is unclear whether the tooth structure will be strengthened to withstand stress or whether the increased stiffness will transmit the load directly to the entire root, potentially causing root fracture. This study compared the fracture resistance and fracture patterns of roots filled with various root canal sealers, including bioceramic sealers, and each corresponding filling technique. Five groups (<i>n</i> = 10) were tested, including no endodontic treatment, no canal obturation, resin-based sealers with continuous-wave compaction, bioceramic sealers with single-cone technique, and mineral trioxide aggregate (MTA) orthograde obturation. The specimens were radiographed to assess the filling quality. After embedding the specimens in acrylic resin, fracture resistance was tested by a universal testing machine, and fracture features were examined microscopically. The results showed that the bioceramic sealer group using the single-cone technique had the highest fracture strength. Radiographic analysis revealed that achieving void-free filling was more difficult with MTA orthograde obturation compared to resin-based and bioceramic sealer groups. No significant variation in fracture features was observed across the groups.