Abstract：
BACKGROUND:The aim of the present study was to evaluate the cyclic fatigue resistance of Mtwo NiTi rotary instruments after clinical use by 1 experienced and 1 novice operator. MATERIAL/METHODS:Cyclic fatigue testing of instruments was performed on tapered artificial canals with a 5 mm radius of curvature and 60° angle of curvature. Twenty Mtwo instruments for each size were selected and divided into 2 groups: group A consisted of 10 instruments of each size used for shaping 10 root canals in molar teeth of patients by an experienced operator; group B consisted of 10 instruments of each size used for shaping 10 root canals in molar teeth of patients by a novice operator. Instruments were rotated until fracture occurred and the numbers of cycles to failure (NCF) were recorded. Data obtained were subjected to an independent sample t-test to determine statistical differences. The significance was determined at a 95% confidence level. RESULTS:No statistically significant difference (P<0.05) was noted between the instruments of groups A and B for all sizes. More instruments with visible signs of plastic deformation were identified for the novice operator. CONCLUSIONS:The clinical use of Mtwo NiTi rotary instruments by a novice operator did not significantly affect the cyclic fatigue resistance when compared with the control group of the same instrument sizes used by an experienced operator. It can be concluded that novice operators can use these instruments safely under the recommended technical guidelines.
journal_name
Med Sci Monitjournal_title
Medical science monitor : international medical journal of experimental and clinical researchauthors
Plotino G,Al-Sudani D,Pulino S,Grande NM,Marcoli PA,Pizzi S,Testarelli L,Gambarini Gdoi
10.12659/msm.882887subject
Has Abstractpub_date
2012-06-01 00:00:00pages
MT41-5issue
6eissn
1234-1010issn
1643-3750pii
882887journal_volume
18pub_type
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journal_title：Medical science monitor : international medical journal of experimental and clinical research
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