Corrosion rates of stainless-steel files in different irrigating solutions.
OBJECTIVE
The present study was designed to evaluate and compare the corrosion rates of the stainless-steel endodontic files when immersed in 0.2% chlorhexidine gluconate, 5.25% NaOCl, chlorinated soda with KOH, and 17% EDTA irrigating solutions.


METHODS
Corrosion rates of stainless-steel K-files in irrigating solutions were determined electrochemically by the Tafel extrapolation method. The cutting flutes of files were immersed in solutions and used as an electrode. A saturated calomel electrode (SCE) was used as a reference, and a platinum plate was used as a counter electrode. In order to determine corrosion rates, the linear part of anodic currents obtained from electrochemical current-potential curves, was extrapolated to corrosion potentials.


RESULTS
The corrosion rates of stainless-steel files in the tested solutions from the highest to the lowest were: 0.2% chlorhexidine gluconate>5.25% NaOCl>chlorinated soda with KOH>17% EDTA. The differences between the corrosion rates of files were not found to be statistically different for chlorinated soda with KOH and EDTA (P >0.05), but statistically significant differences were found amongst other groups.


CONCLUSIONS
The results of the present study indicated that 0.2% chlorhexidine gluconate, 5.25% NaOCl and chlorinated soda with KOH cause severe corrosion on the surface of selected stainless-steel files.
Dartar Oztan
M
M
Department of Endodontics, Faculty of Dentistry, Ankara University, Turkey. mdartar@hotmail.com
Akman
A A
AA
Zaimoglu
L
L
Bilgiç
S
S
D000704:Analysis of Variance; D002710:Chlorhexidine / Q000031:analogs & derivatives*; D003343:Corrosion; D003722:Dental Alloys / Q000737:chemistry; D003762:Dental Instruments; D004492:Edetic Acid; D004563:Electrochemistry; D006878:Hydroxides; D008855:Microscopy, Electron, Scanning; D017680:Potassium Compounds; D012388:Root Canal Irrigants; D018915:Root Canal Preparation / Q000295:instrumentation*; D017693:Sodium Bicarbonate; D012973:Sodium Hypochlorite; D013193:Stainless Steel / Q000737:chemistry; D013499:Surface Properties
D003722:Dental Alloys; D006878:Hydroxides; D017680:Potassium Compounds; D012388:Root Canal Irrigants; D013193:Stainless Steel; D017693:Sodium Bicarbonate; D004492:Edetic Acid; D012973:Sodium Hypochlorite; C010882:chlorhexidine gluconate; D002710:Chlorhexidine; C029943:potassium hydroxide