Thermal and microstructural effects of nanosecond pulsed Nd:YAG laser irradiation on tooth root surface

Abstract

Plaque, calculus and altered cementum removal by scaling and root planing is a fundamental procedure in periodontal treatment. However, the residual smear layer contains cytotoxic and inflammatory mediators which adversely affect healing. Chemical smear layer removal is also problematic.In previous investigations effective smear layer removal was achieved using long pulsed irradiation at 1.06u. However, laser irradiation was not adequate as an alternative to scaling and root planing procedures and concurrent temperature rises exceeded thermal thresholds for pulpal and periodontal safety. It was the aim of this study to determine whether nanosecond pulsed irradiation at l.06u could he used as an alternative or an adjunct to scaling and root planing. 60 freshly extracted teeth were divided as follows: 5 control, 5 root planed only, 25 irradiated only, 25 root planed and irradiated. Irradiation was performed at fluences of ().5-2.7J/cm2, total energy densities of 12-30() J/cm2, frequencies of 2-l() Hz using the Medlite (Continuum) laser. Irradiation-induced thermal events were recorded using a thermocouple within the root canal and a thermal camera to monitor surface temperatures. SEM demonstrated effective smear layer removal with minimal microstructural effects. Surface temperatures increased minimally (<3C) at all parameters, intrapulpal temperature rises remained below 4 C at 2 and 5 Hz, F<O.5 J/cm2. Without prior scaling and root planing, laser effects did not provide an adequately clean root surface.

Emissivity evaluation of human enamel and dentin

“…With increased interest in the use of infrared imaging devices to assess the temperature of mineralized tooth tissue, it is relevant to assess the emissivity of each sample to report a valid temperature. Many in vitro studies have been carried out with thermal imaging devices to assess potential damage to both the soft and mineralized tooth tissue from temperature changes, e.g., during laser application ( Launay, et al, 1987 ; Pogrel, et al, 1988 ; Anić, et al, 1993 ; Arima & Matsumoto, 1993 ; Neev, et al, 1993 ; Arrastia, et al, 1994 ; Anić and Matsumoto, 1995 ; Arrastia, et al, 1995 ; Machida, et al, 1995 ; Wilder-Smith, et al, 1995 ; Anić, et al, 1996a ; Anić, et al, 1996b ; Meyer & Foth, 1996 ; Neev, et al, 1996 ; Whitters & Strang, 2000 ; Yu, et al, 2000 ; Yamazaki, et al, 2001 ; Kishen, et al, 2003 ; Ishizaki, et al, 2004 ; Madura, et al, 2004 ; Wang, et al, 2005 ; Ana, et al, 2007 ; Da Costa Ribeiro, et al, 2007 ; Stock, et al, 2011 ; Da Silva Barbosa, et al, 2013 ; Uzunov, et al, 2014 ; Forjaz, et al, 2022 ), light-curing-composite ( Al-Qudah, et al, 2005 ; Bouillaguet, et al, 2005 ; Aksakalli, et al, 2014 ; Jo, et al, 2019 ; Mouhat, et al, 2021 ), endodontic treatment ( McCullagh, et al, 1997 ; McCullagh, et al, 2000 ; Behnia & McDonald, 2001 ; Lipski and Zapałowicz, 2002 ; Lipski & Woźniak, 2003 ; Lipski, 2004 ; Lipski, 2005a ; Lipski, 2005b ; Lipski, 2006 ; Hsieh, et al, 2007 ; Ulusoy, et al, 2015 ; Diegritz et al, 2020 ; Podolak, et al, 2020 ), pin-placement ( Biagioni, et al, 1996 ), post-removal ( Budd, et al, 2005 ; Lipski et al, 2010a ), cavity preparation and r...…”

Effects of cavity preparation using a nanosecond-pulsed Nd-YAG laser on tooth-restoration interface

“…Thus, short laser pulses can result in reduced collateral, thermal and structural damage. Thermal studies performed using the nanosecond-pulsed Nd-YAG laser have indeed demonstrated the capability of this laser to ablate dentin with reduced thermal effects in adjacent dental tissues (22,(24)(25)(26), as compared with those of conventional Nd-YAG lasers available to dental clinicians.…”