Effect of Hydrogen Peroxide on Cyclic Fatigue Resistance of NiTi Endodontic Files

Abstract

OBJECTIVE: To investigate the effect of nickel titanium rotary endodontic file immersion in hydrogen peroxide on cyclic fatigue resistance. METHODOLOGY: Twenty Six Protaper Universal (Dentsply Maillerfier) F1 files were randomly divided into two experimental groups. In Group I, Protaper universal variable taper F1 files were immersed in normal saline where as in Group II, the files were soaked in hydrogen peroxide (6% w/v) for 2 hours at 37°C. Cyclic fatigue of each file was checked by recording the number of rotations required to break a file in a 90°curve with a 5 mm radius. For statistical analysis of data, Two-way ANOVA was applied. A p value of <0.05 was considered significant. RESULT: Out of Twenty Six, Six files fractured spontaneously after immersion in hydrogen peroxide. Twenty files were subjected to fracture resistance testing. Statistically significant difference in cyclic fatigue resistace between the two groups was found (p=0.002). The files soaked in Group II required less revolutions to fracture than the ones immersed Group I. CONCLUSION: The immersion of NiTi endodontic files in hydrogen peroxide significantly reduces cyclic fatigue resistance. Therefore, immersion of the NiTi endodontic files in hydrogen peroxide solution for removal of clogged debris should be discouraged. KEYWORDS: Cyclic fatigue, Endodontic instruments, Hydrogen peroxide, NiTi HOW TO CITE: Sarwar H, Naeem MM, Shabbir S, Riaz S, Afaq H, Shabbir J. Effect of hydrogen peroxide on cyclic fatigue resistance of NiTi endodontic files. J Pak Dent Assoc 2020;29(4):246-248.