Root Surface Temperature Changes during Root Canal Laser Irradiation with Dual Wavelength Laser (940 and 2780 nm): A Preliminary Study

Haidary, Darya; Franzen, Rene ́; Gutknecht, Norbert

	Root Surface Temperature Changes during Root Canal Laser Irradiation with Dual Wavelength Laser (940 and 2780 nm): A Preliminary Study
Sulaimani Dental Journal
Article 11, Volume 4, Special Issue, 2017, Pages 11-11 PDF (387.7 K)
Authors
Darya Haidary; Rene ́ Franzen; Norbert Gutknecht
Abstract
Objective: This study aimed to evaluate the temperature changes on the root surface during root canal irradiation using 2780 nm erbium, chromium: yttrium, scandium, gallium, garnet (Er,Cr:YSGG) and 940 nm diode lasers in an alternating sequence. Materials and method: Eighteen single-rooted human teeth were randomly divided into three groups (n = 6). The teeth were embedded in a resin block, and six thermocouples were introduced at different positions on the tooth surfaces, while immersed in a 37_C thermal bath during laser irradiation. The laser radial firing tip (RFT2) was operated in helicoidal movements and withdrawn from the root canal in a coronal direction at a speed of 2 mm/sec. Group A was irradiated with the Er,Cr:YSGG laser (1.25 W, 25 mJ, 50 Hz, 50 ls pulse duration, 50% water, and 30% air spray); Group B was irradiated with the Er,Cr:YSGG laser (same settings) and a 940 nm diode (2 W, with 20% duty cycle); and Group C was irradiated with the Er,Cr:YSGG laser (same settings) and a 940 nm diode (2 W, 50% duty cycle). Method: The same steps are followed for each tooth, 1-Use extracted molar and premolar teeth. 2-Take Preoperative radiographs from 2 angles (direction): from bucco-lingual (palatal) and mesial-distal angles for all teeth, to see the anatomy of root canal space from these hidden angles. 3-Access the canals under 4X loupes or Microscope (DOM). 4- Shape the canal by hand file and take Radiographs from both bucco-lingual & mesial-distal angulation. 5-Close the canals using traditional hand gutta percha and take Radiographs from both bucco-lingual & mesial-distal angulation. 6- Remove hand gutta percha and continue rotary shaping to the same sizes as with hand files. 7- Close the canals with rotary gutta percha and take Radiographs from both bucco-lingual & mesial-distal angulation. 8- Remove rotary gutta percha and inject hot gutta percha by continuous wave technique and take Radiographs from both bucco-lingual & mesial-distal angulation. Results: The maximum temperature recorded was in the apical thirds of Groups A–C, resulting in increments of 8.35_C, 7.33_C, and 3.82_C, respectively. All measured temperatures were considerably below the critical value of 10_C. Conclusion: The alternate use of Er,Cr:YSGG and 940 nm diode lasers can be considered biologically safe for application in endodontics.

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