When a perforation occurs during root canal treatment, the choice of repair material can significantly influence the prognosis. An ideal material should not only provide an excellent seal but also resist dislodgement during restorative procedures and remain stable in the moist environment of the root canal.
A recent in vitro study compared the performance of the recently introduced TheraCal PT with Biodentine, one of the most commonly used calcium silicate-based repair materials, to determine how the two materials perform in perforation repair.
Researchers evaluated four clinically important properties—marginal adaptation, push-out bond strength, solubility and microleakage—using extracted mandibular premolars with standardized artificial perforations.
The findings revealed that neither material outperformed the other across all parameters.
Scanning electron microscope analysis showed that Biodentine adapted more closely to dentine, producing significantly smaller marginal gaps than TheraCal PT. Better marginal adaptation is generally associated with improved sealing at the repair interface.
However, TheraCal PT demonstrated significantly higher push-out bond strength, suggesting greater resistance to dislodgement during restorative procedures or under functional forces. The material also exhibited significantly lower solubility after immersion testing, indicating better dimensional stability over time.
When researchers evaluated microleakage using methylene blue dye penetration, TheraCal PT again showed favourable results. One-third of the TheraCal PT samples exhibited no dye penetration at all, whereas none of the Biodentine specimens achieved complete resistance to leakage. Overall, the difference in microleakage between the two materials was statistically significant.
The authors suggest that the improved bond strength and lower solubility of TheraCal PT may be related to its dual-cure resin-modified calcium silicate composition, which allows immediate light curing while enhancing adhesion. Biodentine's superior marginal adaptation, on the other hand, is thought to result from its smaller particle size, enabling closer adaptation to dentine surfaces.
Based on the overall findings, the researchers concluded that TheraCal PT may serve as a promising alternative to Biodentine for perforation repair, demonstrating superior push-out bond strength, lower solubility and reduced microleakage. Nevertheless, Biodentine continued to show better marginal adaptation.
The authors also caution that these results were obtained under laboratory conditions. Factors such as oral fluids, tissue response and long-term clinical function could not be replicated, and larger clinical studies are required before these findings can be translated into routine clinical practice.
Chairside Takeaway
This study highlights that no single repair material excelled in every category. While Biodentine achieved better marginal adaptation, TheraCal PT showed greater resistance to dislodgement, lower solubility and less microleakage. Although the findings are encouraging for the newer material, clinical trials are still needed before recommending a change in routine perforation repair protocols.