Effect of sodium hypochlorite, EDTA, and chitosan solution on corrosion and quantity of extruded nickel ions using two rotary instruments (In Vitro)

Abstract

Aim: To compare the effect 2.5% NaOCl, 17% ethylenediaminetetraacetic acid (EDTA), and 0.2% high molecular chitosan solution during root canal preparation using ProTaper Universal and iRace rotary file on corrosion of NiTi instrument and quantity of apically extruded nickel ions. Materials and methods: Twenty-four extracted human premolars were divided into 4 groups. Group I was the sample with root canal preparation using ProTaper Universal rotary file with 2.5% NaOCl and 17% EDTA, group II was the sample using ProTaper Universal rotary file with 2.5% NaOCl and 0.2% high molecular chitosan solution, group III was the sample using iRace rotary file with 2.5% NaOCl and 17% EDTA, and group IV was the sample using iRace rotary file with 2.5% NaOCl and 0.2% high molecular chitosan solution. After root canal preparation, the quantity of apically extruded nickel ions was evaluated using atomic absorption spectrophotometry (AAS). Instruments were evaluated for corrosion and surface defect using a scanning electron microscope. Results: A combination of 2.5% NaOCl and 0.2% high molecular chitosan solution caused significantly lower corrosion and surface defect in ProTaper Universal and iRace rotary files and also produced fewer extrusions of nickel ions compared to a combination of 2.5% NaOCl and 17% EDTA. The mean value of corrosion and surface defect scores on iRace was lower and also resulted in less extrusion of nickel ions compared to ProTaper Universal rotary. Conclusion: 0.2% high molecular chitosan solution can be developed as a chelating material, an alternative to EDTA.