Results
Title

CYCLIC FATIGUE RESISTANCE EVALUATION OF HEAT-TREATED ROTARY FILES AFTER IMMERSION IN NAOCL AND EDTA: AN IN VITRO STUDY.

Authors

Hadakie, Ruba; Alaja, Taher

Abstract

INTRODUCTION: Rotary file fracture during its rotation inside root canal is considered an important clinical problem. Corrosion is one of the factors that affect the instrument's life-time, and decreases fracture resistance. OBJECTIVES: This study assessed the effect of immersion in different irrigation solutions on cyclic fatigue resistance using two types of nickel-titanium rotary files. Material and methods: Sixty new nickel-titanium rotary files (30 AF files, 30 Plex-V files) were chosen. Each type of files were divided into three groups: control, NaOCl, and EDTA. Instruments were immersed in solutions for 15 min at room temperature. After immersion, cyclic fatigue of files was tested by rotating the files in an artificial stainless-steal canal, with a 120-degree angle and 2.5 mm radius of curvature. The instruments rotated until a fracture occurred, and time to fracture was recorded in seconds. NCF was also calculated, and data were statistically analyzed with one-sample Kolmogorov-Smirnov, Mann-Whitney, and Kruskal-Wallis H tests. A p-value of less than 0.05 was considered statistically significant. RESULTS: Cyclic fatigue results showed a statistically significant difference between Plex-V files, which had the highest resistance to fatigue compared with AF files (p < 0.001). Statistical analysis was performed to determine which irrigation solutions had the most effect on resistance in each brand. CONCLUSIONS: Sodium hypochlorite solution had the most effect on the cyclic fatigue resistance of AF files, while EDTA solution had the strongest effect on reducing fatigue resistance of Plex-V files. However, Plex-V instruments demonstrated better fatigue resistance compared with AF instruments.

Subjects

FATIGUE limit; CYCLIC fatigue; DENTAL pulp cavities; STATISTICS; SODIUM hypochlorite

Publication

Journal of Stomatology, 2024, Vol 77, Issue 3, p168

ISSN

0011-4553

Publication type

Academic Journal

DOI

10.5114/jos.2024.143585