Obturation Material and Technique Significantly Affect Strength of Immature Teeth: Study

A new research published in the journal of BMC Oral Health showed that root canal filling materials and coronal backfilling techniques significantly influence the biomechanical behavior of immature teeth during apexification procedures. Thermoplasticized gutta-percha provided better reinforcement than dual-cure composite resin, while Biodentine and TotalFill RRM Putty showed similar mechanical performance. The findings highlight the importance of appropriate material selection and obturation strategy in improving the structural integrity of immature roots.

This research investigated how different root canal filling materials and coronal backfilling techniques influence the fracture resistance of immature teeth in restorative dentistry. Immature teeth are particularly vulnerable because their underdeveloped roots and thin dentinal walls make them more susceptible to fractures after trauma or infection.

The in vitro study evaluated 64 simulated immature maxillary central incisors that were randomly divided into 8 experimental groups. The teeth underwent apexification procedures using either Biodentine or TotalFill RRM Putty, two bioactive materials increasingly used in endodontic therapy. These materials were tested alone or combined with thermoplasticized gutta-percha or a dual-cure composite resin known as Grandio Core.

Thus, this study subjected the treated teeth to fracture resistance testing using a universal testing machine. Fracture patterns were also examined and categorized as either restorable or unrestorable, providing additional insight into the clinical implications of each treatment strategy.

The findings revealed that the positive control group showed the weakest resistance, which confirmed the fragility of untreated immature roots. However, teeth treated with Biodentine, Biodentine combined with thermoplasticized gutta-percha, and TotalFill RRM Putty combined with gutta-percha demonstrated fracture resistance levels comparable to intact teeth in the negative control group.

The teeth restored with gutta-percha consistently exhibited higher fracture resistance than those restored with the dual-cure composite resin. This suggests that the flexibility and stress-distributing properties of thermoplasticized gutta-percha may better support weakened immature roots during function.

The study found no major mechanical difference between Biodentine and TotalFill RRM Putty, which indicated that both materials can perform effectively during apexification procedures when paired with appropriate obturation strategies.

Overall, the findings of this study suggest that both the choice of root canal filling material and the coronal backfilling technique play decisive roles in the biomechanical behavior of immature teeth. Selecting suitable bioactive materials along with thermoplasticized gutta-percha may significantly improve the long-term structural integrity of immature roots.

Source:

Düzgün, S., Akyüz, İ. E., & Çi̇çek, M. (2026). Effect of different materials and canal filling methods in apexification of simulated immature teeth on fracture resistance-in vitro study. BMC Oral Health. https://doi.org/10.1186/s12903-026-08369-5