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Temperature rise on the surface of NiTi and stainless steel fractured instruments during ultrasonic removal
Author(s) -
Madarati A. A.
Publication year - 2015
Publication title -
international endodontic journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.988
H-Index - 119
eISSN - 1365-2591
pISSN - 0143-2885
DOI - 10.1111/iej.12383
Subject(s) - nickel titanium , materials science , ultrasonic sensor , metallurgy , composite material , acoustics , shape memory alloy , physics
Aim To investigate the temperature rise induced by ultrasonic tips when activated against two types of fragments at two power‐settings. Methodology Twenty‐four F2‐ProTaper Universal rotary files and 36 stainless steel K‐files, size 50, were sectioned at a point 5.5 mm from their tips. At specific power‐settings, ET40D ultrasonic tips were activated against the peripheral surface of the fragment coronal part (1 mm) for 30 s with/without Air‐Active function according to each group; (i) without Air‐Active function at power‐setting 1.5 against NiTi fragments, (ii) without Air‐Active function at power‐setting 1.5 against SS fragments, (iii) without Air‐Active function at power‐setting 3 against SS fragments, (iv) with Air‐Active function at power‐setting 3 against SS fragments, and (v) with Air‐Active at power‐setting 3 against NiTi fragments. Temperature rises were inspected at 15 and 30 s using the thermocouples. Results With no Air‐Active function and power‐setting 1.5, the temperature rises induced on NiTi fragments at 15 and 30 s (36.33 and 55.44 °C, respectively) were significantly greater than those induced on SS fragments at 15 and 30 s (26.08 and 35.27 °C, respectively) ( P = 0.001 and <0.001, respectively). When ultrasonic tips were activated against SS fragments without Air‐Active, the temperature rises induced by power‐setting 3 at 15 and 30 s (35.25 and 45.32 °C, respectively) were significantly greater than those induced by power‐setting 1.5 at the same intervals (26.08 and 35.27 °C, respectively) ( P = 0.006 and 0.012, respectively). At 30 s, the overall temperature rise induced with Air‐Active (25.56 °C) was significantly lower than that induced without Air‐Active (45.34 °C) ( P < 0.001). Conclusions Lower power‐settings and shorter application times are recommended when using ultrasonics for removal of NiTi fragments compared with SS ones. Air‐Active function, as a coolant, is recommended when dealing with both types of fragments.