Introduction: Creation of a sterile space is impossible in infected root canals, using mechanical preparation alone due to the complication configuration of radicular canal systems. Nearly half of the radicular canal dentine were left unprepared during the mechanical preparation with traditional stainless steel hand instruments and endodontic instruments.Aim; Evaluation of the outcome of numerous irrigating solutions used as final irrigation on the depth of sealer penetration into dentinal tubules.Methods: Two different endodontic sealers Bioceramic sealer and Resin sealer were used with four different irrigating solutions (Sodium hypochlorite, Chlorhexidine digluconate, Chiostan nanoparticles, Bio pure MTAD). GROUP 1: 5 ML of 2 % of naocl were used as a final irrigant for 1 min. GROUP 2: 5 ML of 2% chlorhexidine were used as a final irrigant for 1min. GROUP 3: 5ML of 0.2% of chitosan nanoparticles were used as a final irrigant for 1 min. GROUP 4: 5ML of MTAD were used as a final irrigant for 1 min. Depth of sealer penetration into dentinal tubules was evaluated after samples preparation using confocal laser microscope analysis. Results:Comparison between different sealers of all irrigants in the coronal section was performed by using Independent T-test which revealed that MTA fill apex was significantly higher than AH plus as P < 0.05 in NaoCl. Conclusion:MTA Fill apex sealer exhibited a significantly greater dentinal penetration than AH plus sealer irrespective of the final irrigation protocol.

This study aimed to evaluate effect of Nano hydroxyapatite coated by Chitosan (NHAP/CS) and bioactive glass nano particulates (nBG) on odontogenic differentiation and proliferation of human dental pulp stem cells (hDPSCs).Methods: hDPSCs were seeded in direct contact with the corresponding Nano-biomaterials in 5 groups: Group (Ι): NHAP (10µg/ml), Group (ΙΙ): NHAP/CS (10µg/ml), Group (ΙΙΙ): nBG (500µg/ml). Group (IV): hDPSCs were cultured with osteogenic medium as a positive control while Group (V): hDPSCs were cultured with Dulbecco's Modified Eagle Medium (DMEM) only as a negative control. Odontogenic differentiation was evaluated based on mineralization related genes .Gene expressions were verified using alkaline phosphatase (ALP) assay and immunofluorescence staining of Dentin matrix protein (DMP-1). Proliferation of cells was evaluated via Trypan Blue staining test and methylthiazol tetrazolium (MTT) assay.Results: All the tested Nano biomaterials exhibited favorable media for odontogenic differentiation and proliferation of hDPSCs. NHAP/CS showed the highest proliferation index via MTT, highest ALP concentration and highest DMP-1Immunofluorescence staining.Conclusions: Compared to pure NHAP and a major biomaterial as nBG, NHAP/CS can induce odontogenic differentiation and proliferation of hDPSCs and could be considered as a good candidate for dentin-pulp regenerative procedures.