E Schäfer1. 1. Department of Operative Dentistry, University of Münster, Münster, Germany. eschaef@uni-muenster.de
Abstract
AIM: To investigate alterations in cutting efficiency when conventional and titanium nitride (TiN) coated nickel-titanium (NiTi) K-files were exposed to repeated sterilization using an autoclave. METHODOLOGY:A total of 96 NiTi K-files (size 35) were randomly divided into two groups (A and B) of 48 instruments each. Whilst the instruments of group B were exposed to physical vapour deposition (PVD) creating a coating of a TiN layer, the files of group A were not coated. The instruments of groups A and B were randomly divided into four subgroups of 12 instruments each. A.1/B.1: Instruments were exposed to five cycles of sterilization. A.2/B.2: Instruments were exposed to 10 cycles of sterilization. A.3/B.3: Instruments were immersed in NaOCl for 30 min, rinsed in water, and exposed to five cycles of sterilization. A.C/B.C: Instruments were not sterilized (controls). The cutting efficiency of all files was determined by means of a computer-driven testing device. Special plastic samples with cylindrical canals were used and the maximum penetration depth of the files into the lumen was assessed. RESULTS: The TiN-coated instruments of groups B.1, B.2 and B.3 showed no significant difference in comparison with the penetration depths of the controls (P> 0.05). The uncoated files of groups A.1, A.2 and A.3 displayed significantly lower maximum penetration depths (P< 0.05) when compared to the control files. CONCLUSIONS:Repeated sterilization under autoclave or exposure to sodium hypochlorite (NaOCl) prior to sterilization did not alter the cutting efficiency of PVD-coated NiTi K-files.
RCT Entities:
AIM: To investigate alterations in cutting efficiency when conventional and titanium nitride (TiN) coated nickel-titanium (NiTi) K-files were exposed to repeated sterilization using an autoclave. METHODOLOGY: A total of 96 NiTi K-files (size 35) were randomly divided into two groups (A and B) of 48 instruments each. Whilst the instruments of group B were exposed to physical vapour deposition (PVD) creating a coating of a TiN layer, the files of group A were not coated. The instruments of groups A and B were randomly divided into four subgroups of 12 instruments each. A.1/B.1: Instruments were exposed to five cycles of sterilization. A.2/B.2: Instruments were exposed to 10 cycles of sterilization. A.3/B.3: Instruments were immersed in NaOCl for 30 min, rinsed in water, and exposed to five cycles of sterilization. A.C/B.C: Instruments were not sterilized (controls). The cutting efficiency of all files was determined by means of a computer-driven testing device. Special plastic samples with cylindrical canals were used and the maximum penetration depth of the files into the lumen was assessed. RESULTS: The TiN-coated instruments of groups B.1, B.2 and B.3 showed no significant difference in comparison with the penetration depths of the controls (P> 0.05). The uncoated files of groups A.1, A.2 and A.3 displayed significantly lower maximum penetration depths (P< 0.05) when compared to the control files. CONCLUSIONS: Repeated sterilization under autoclave or exposure to sodium hypochlorite (NaOCl) prior to sterilization did not alter the cutting efficiency of PVD-coated NiTi K-files.
Authors: Youssef S Al Jabbari; Theodoros Koutsoukis; Suliman Al Hadlaq; David W Berzins; Spiros Zinelis Journal: J Dent Sci Date: 2015-11-19 Impact factor: 2.080