In vitro comparison of dentinal superficial micro-hardness change between two endodontic irrigation sequences

Abstract

Objectives: to compare changes in surface microhardness of dentinal root (MSD) with two irrigation sequences (SI) using a Vickers microhardness test (VHN). Methods: 20 samples were prepared by longitudinal cutting of 10 unirradiculated human tooth. Two IS were prepared, a traditional one (5% NaOCl, saline 0,9%, 17% EDTA and saline 0,9%) and a modified one (traditional plus a final irrigation of 5% NaOCl), each irrigant isolated in a glass plate. In two groups of 10 samples (traditional IS and modified IS) 5 identations were performed by a Vickers microdurometer prior and after the IS immersion of the samples. The average of Vickers microhardness (VMT) of the samples was obtained and compared statistically. 0.05 P value. Results: A statistical difference of superficial microhardness was found among pre-irrigation (control) and post-irrigation in both protocols. Nonetheless, there was not a statistical difference among both protocols. Use of EDTA followed by NaOCl did not show a significant decrease of dentinal superficial microhardness. Conclusion: Use of NaOCl after EDTA did not show a significant decrease of dentinal superficial microhardness. Objectives: to compare changes in surface microhardness of dentinal root (MSD) with two irrigation sequences (SI) using a Vickers microhardness test (VHN).Methods: 20 samples were prepared by longitudinal cutting of 10 unirradiculated human tooth. Two IS were prepared, a traditional one (5% NaOCl, saline 0,9%, 17% EDTA and saline 0,9%) and a modified one (traditional plus a final irrigation of 5% NaOCl), each irrigant isolated in a glass plate. In two groups of 10 samples (traditional IS and modified IS) 5 identations were performed by a Vickers microdurometer prior and after the IS immersion of the samples. The average of Vickers microhardness (VMT) of the samples was obtained and compared statistically. 0.05 P value.Results: A statistical difference of superficial microhardness was found among pre-irrigation (control) and post-irrigation in both protocols. Nonetheless, there was not a statistical difference among both protocols. Use of EDTA followed by NaOCl did not show a significant decrease of dentinal superficial microhardness.Conclusion: Use of NaOCl after EDTA did not show a significant decrease of dentinal superficial microhardness.