Effects of sodium hypochlorite on nickel-titanium Lightspeed instruments.
Sodium hypochlorite is a major irrigant in endodontics, and nickel-titanium instruments are gaining in popularity. This paper investigated the corrosion of nickel-titanium Lightspeed instruments in 1% and 5% NaOCl solutions. The instruments were immersed in ultrasonicated NaOCl solutions for varying times up to 1 h. Corrosion was determined by electrothermal absorption spectrometry in 100 microL aliquots of NaOCl. Background contamination of nickel in the 1% and 5% NaOCl solutions used was low, but high enough to interfere in detecting any increases in nickel after immersing the instruments. The amounts of titanium recorded in the 1% NaOCl solutions were insignificant. However, a statistically significant amount of titanium was detected from the Lightspeed instruments after immersion times of 30 and 60 min in 5% NaOCl. Clinically such instruments do not have an 'in situ' time of 30 min, and this corrosion may be considered irrelevant clinically.
Busslinger
A
A
Department of Preventive Dentistry, University of Zurich, Switzerland.
Sener
B
B
Barbakow
F
F
D000704:Analysis of Variance; D003343:Corrosion; D003762:Dental Instruments; D009532:Nickel / Q000737:chemistry*; D012388:Root Canal Irrigants / Q000737:chemistry*; D018915:Root Canal Preparation / Q000295:instrumentation*; D012973:Sodium Hypochlorite / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*
D012388:Root Canal Irrigants; C040654:titanium nickelide; D009532:Nickel; D014025:Titanium; D012973:Sodium Hypochlorite