Effect of intracanal dentine wettability on human dental pulp cell attachment

Aim To evaluate the effect of intracanal dentine wettability on human dental pulp cell (HDPC) attachment after application of endodontic irrigants. Methodology Twenty extracted human premolar teeth with straight canals were sectioned at the apical and coronal thirds of each root, and the remaining mid-root portions were bisected longitudinally. After polishing, the specimens were divided into two groups for wettability and cell attachment measurements, respectively. The intracanal surface wettability was assessed by atomic force microscopy after a rinse of H₂O (control), 5.25% sodium hypochlorite (NaOCl), 17% ethylenediaminetetraacetic acid (EDTA) and MTAD (n=5). Additionally, HDPCs were seeded onto the irrigated root canal dentine and the cell attachment was evaluated by calcein-CAM and propidium iodide (PI) dying under fluorescence microscope (n=5). Data were analysed by means of one-way anova and LSD test. Results Compared with the control group, 5.25% NaOCl, 17% EDTA and MTAD treatment significantly increased surface wettability (P<0.001). The rank order of adhesion force was MTAD >17% EDTA >5.25% NaOCl>H₂O. The highest average numbers of viable HDPCs were observed on the root canals irrigated with MTAD, followed by the 17% EDTA group (P<0.001), and the lowest average numbers of viable cells were detected in the 5.25% NaOCl and H₂O groups. Conclusions Surface wettability was affected by the irrigants. Increasing in wettability produced higher levels of HDPC attachment to irrigated dentine.