ABSTRACT
This study aimed to determine the antimicrobial efficacy of NaOCl, cetrimide, and Glycyrrhiza glabra L. extract against Enterococcus faecalis biofilms on dentine discs. Broth microdilution method was used to determine minimal bactericidal concentrations (MBCs) of the agents. A biofilm susceptibility assay was performed using E. faecalis biofilms grown on dentine discs. Minimal bactericidal concentrations (MBCs) of NaOCl (0.5%), cetrimide (0.015%), and G. glabra L. extract (0.25%) were applied for 1, 3, and 5 min, and the mean viable cell counts were recorded and statistically analyzed. There was no significant difference between cetrimide and NaOCl at 1 min (p>0.05). NaOCl was the most effective agent at 3 and 5 min (p<0.05) while G. glabra L. extract was the least (p<0.05). The MBCs of NaOCl, cetrimide, and G. glabra that eliminated the planktonic E. faecalis did not eradicate the biofilms grown on dentin discs.
Subject(s)
Biofilms , Cetrimonium Compounds , Enterococcus faecalis , Anti-Infective Agents , Dentin , GlycyrrhizaABSTRACT
NiTi instruments have a high risk of separation due to torsional or flexural fatigue (cyclic fatigue). Chemomechanical preparation, cleaning procedures, chemical disinfection and sterilization cause the corrosion of endodontic instruments that may weaken the fracture resistance of the instruments. Objective To assess the effects of NaOCl immersion and autoclave sterilization on the cyclic fatigue resistance of ProFile, FlexMaster, Mtwo and TwistedFiles NiTi instruments (tip size 25, 0.06 taper, n=160). Material and Methods The instruments (n=10 for each subgroup) were dynamically immersed in NaOCl; immersed in NaOCl and sterilized in one autoclave cycle; 5 cycles immersed in NaOCl and sterilized in autoclave and not immersed in NaOCl and not sterilized (control group). Dynamic cyclic fatigue resistance was tested. The number of cycles to failure (NCF) were statistically analyzed (P<0.05). Results Kruskall-Wallis test indicated significant differences among the tested instruments in terms of NCF (P=0.000). The mean NCF of Mtwo (556.75) was higher than that of the Twisted File, Flexmaster and ProFile, 483.1, 376.12, 365.25, respectively. NaOCl immersion and autoclave sterilization have no effect on the NCF values of the tested instruments (P>.05). Conclusions Cyclic fatigue resistance of the tested NiTi instruments cannot be adversely affected by NaOCl immersion and autoclave sterilization. Production process (TwistedFiles) or design (Twisted Files, FlexMaster, Mtwo and ProFile) of the instruments can influence their cyclic fatigue resistance. .
Subject(s)
Dental Instruments , Disinfectants/chemistry , Nickel/chemistry , Root Canal Preparation/instrumentation , Sodium Hypochlorite/chemistry , Sterilization/methods , Titanium/chemistry , Equipment Failure , Immersion , Materials Testing , Statistics, Nonparametric , Stress, Mechanical , Surface Properties , Tensile Strength/drug effects , Time FactorsABSTRACT
NiTi instruments have a high risk of separation due to torsional or flexural fatigue (cyclic fatigue). Chemomechanical preparation, cleaning procedures, chemical disinfection and sterilization cause the corrosion of endodontic instruments that may weaken the fracture resistance of the instruments. Objective To assess the effects of NaOCl immersion and autoclave sterilization on the cyclic fatigue resistance of ProFile, FlexMaster, Mtwo and TwistedFiles NiTi instruments (tip size 25, 0.06 taper, n=160). Material and Methods The instruments (n=10 for each subgroup) were dynamically immersed in NaOCl; immersed in NaOCl and sterilized in one autoclave cycle; 5 cycles immersed in NaOCl and sterilized in autoclave and not immersed in NaOCl and not sterilized (control group). Dynamic cyclic fatigue resistance was tested. The number of cycles to failure (NCF) were statistically analyzed (P<0.05). Results Kruskall-Wallis test indicated significant differences among the tested instruments in terms of NCF (P=0.000). The mean NCF of Mtwo (556.75) was higher than that of the Twisted File, Flexmaster and ProFile, 483.1, 376.12, 365.25, respectively. NaOCl immersion and autoclave sterilization have no effect on the NCF values of the tested instruments (P>.05). Conclusions Cyclic fatigue resistance of the tested NiTi instruments cannot be adversely affected by NaOCl immersion and autoclave sterilization. Production process (TwistedFiles) or design (Twisted Files, FlexMaster, Mtwo and ProFile) of the instruments can influence their cyclic fatigue resistance.
