Adhesive performance and failure modes of hydroxyapatite coated gutta percha with different root canal sealers

This study evaluates the adhesive performance of a novel hydroxyapatite-coated gutta-percha (HAGP) in combination with various root canal sealers, using push-out bond strength testing and failure mode analysis. Eighty human single-canal teeth were divided into four groups: three test groups obturated with HAGP using AH Plus, iRoot SP, or GuttaFlow Bioseal, and one control group obturated with conventional gutta-percha (GP) with AH Plus sealer. Push-out bond strength was assessed after 30 days with a universal testing machine, and failure modes were analysed under stereomicroscopy. Results revealed a significantly higher bond strength (p < 0.001) for HAGP compared to the control, regardless of the sealer used. Failure analysis indicated 62.5% mixed failures and 37.5% cohesive failures, with no adhesive failure observed. These findings suggest that HAGP significantly improves gutta-percha adhesion, as demonstrated through the higher bond strength compared to conventional gutta-percha.