Open Journal of Stomatology, 2012, 2, 286-291 OJST http://dx.doi.org/10.4236/ojst.2012.24050 Published Online December 2012 (http://www.SciRP.org/journal/ojst/ ) Measurement of temperature changes during cavitation generated by an erbium, chromium: Yttrium, scandium, gallium garnet laser * Harry Huiz Peeters 1 , Latief Mooduto 2 1 Laser Research Center, Bandung, Indonesia 2 Department of Endodontics, School of Dentistry, University of Airlangga, Surabaya, Indonesia Email: h2huiz@cbn.net.id Received 4 October 2012; revised 13 November 2012; accepted 20 November 2012 ABSTRACT Aim: The present study evaluated the magnitude of temperature changes in the tooth during cavitation produced by an Er,Cr:YSGG laser. Methods: The root canal of a single extracted maxillary canine was enlarged to a size 30/.02 file. Four thermocouples were attached to the tooth: one to the surface of the root and three inserted into the canal at 3, 9, and 15 mm from the apical foramen, respectively. The tooth was placed in a plastic container at room temperature around 25˚C. The tooth was processed as follows. In the EDTA condition, the tooth was irrigated with 17% EDTA; in the NaOCl condition, the tooth was irrigated with 3% NaOCl; and to analyse the effect of different thicknesses of dentin, the tooth was irrigated with tap water. In all conditions, the irrigants were activated at 2 W for 120 seconds. Results: The mean temperature was 25.2˚C to 27.1˚C and the tempera- ture ranged from 25.0˚C to 29.6˚C. The temperature elevation measured during cavitation generated by the laser didnot exceed 5˚C. Conclusions: The mag- nitude of the temperature changes in the root canal and at the surface of the tooth did not exceed 5˚C when laser-driven irrigation was used to produce cavitation in the root canal. Keywords: Cavitation; Heat; Laser-Driven Irrigation; Temperature Changes 1. INTRODUCTION Shaping of the root canal has improved with advances in metal technology. However, owing to the anatomical complexity and irrigurarity of teeth, cleaning of the canal still relies heavily on the adjunctive use of chemical rinsing and soaking solutions [1]. The irrigation proce- dure is a very important part of root canal treatment. However, hand irrigation is not sufficiently effective in the apical third of the root canal, or in oval extensions, isthmuses, and anastomoses [2]. Vapour lock that results in trapped air in the apical third of the root canal may also hinder the exchange of irrigants and decrease the efficacy of debridement [3]. To enhance the dispersal of the irrigant and to activate it, sonic and ultrasonic techniques have been investigated and developed. The use of lasers has been proposed as an alternative to conventional approaches to cleaning and disinfection [2]. Both ultrasound and pulsed middle infra- red lasers cause cavitation and pressure waves within the root canal space [4]. Various types of laser (such as Di- ode, Nd:YAG, Er:YAG or CO 2 ) have been investigated in an attempt to develop improved treatment methods, and the performance of lasers that are used in the field of dentistry has been improving [5]. In a previous study, evaluation by scanning electron microscopy (SEM) revealed that the laser-driven irrigation system under evaluation had the ability to remove the smear layer at the root tip [6]. This capacity could be attributed to the ability of the laser-driven irrigation system to create cavitation. Cavitation is defined as the formation of vapor or a cavity that contains bubbles in- side a fluid [7]. In water, the use of a laser at ablative settings can result in the formation of large elliptical bubbles. These vapor bubbles can cause expansion to 1600 times the original volume of the water [8]. This process can allow the irrigant to access the apical third of the canal more easily, which might assist in the cleaning of canals of irregular shape. In addition, cavitation bub- bles expand, become unstable, and then collapse in what is termed implosion [9]. The implosion will have an im- pact on the surfaces of the root canal, causing shear forces, surface deformation, and the removal of surface material [10]. Using cinematic holography, Ebeling and Lauterborn observed shock waves that emanated from * The authors deny any conflicts of interest related to this study. OPEN ACCESS