Microtissue engineering root canal dentine with crosslinked biopolymeric nanoparticles for mechanical stabilization.

AIM: To evaluate the functional strain distribution pattern in root dentine following canal preparation and root canal surface engineering with crosslinked biopolymeric nanoparticles using digital moire interferometry (DMI). METHODOLOGY: Root dentine specimens were prepared, grating material replicated and tested for 10-50 N, compressive loads in a customized high-resolution, whole-field moire interferometry set-up. Digital moire fringes were acquired to determine the strain distribution pattern at specific regions of interest before and after canal enlargement, and dentine surface engineering with a chitosan nanoparticle crosslinker solution. Fringe patterns were acquired, and strain distribution pattern in the direction perpendicular to dentinal tubules (U-field) and parallel to dentinal tubules (V-field) was analysed with custom digital image-processing software. Data were analysed with a statistical method on trend analysis at 0.05 significant level. RESULTS: Distinct deformation patterns perpendicular to the dentinal tubules were observed in root dentine. Root canal dentine removal following instrumentation resulted in an increase in strain distribution, which increased with an increase in applied loads (P < 0.01). The root canal dentine engineered with crosslinked nanoparticles demonstrated a conspicuous decrease in previously increased strain distribution in both coronal and apical root dentine (P < 0.01). A significant increase in tensile strain in root dentine was observed subsequent to instrumentation in the direction parallel to dentinal tubules (P < 0.01). There was a significant reduction in the tensile strain formed at the apical region of the instrumented root dentine following crosslinked nanoparticle treatment (P < 0.05). CONCLUSIONS: This study highlighted the potential of root canal dentine microtissue engineering with crosslinked chitosan nanoparticle to improve radicular strain distribution patterns in instrumented canals.