OBJECTIVES: The objective of this study was to evaluate the potential effects on underlying dental hard tissues of a high pulse rate carbon dioxide (CO2) laser that was designed for soft tissue surgery. METHODS: Eighteen extracted human teeth were sectioned longitudinally, cleaned, and varnished, leaving nine exposed windows on each: six on the coronal surface (enamel) and three on the root surface (cementum, dentin). The CO2 irradiation conditions used were: wave length 10.6 microm; 1.2-2.6J/cm(2) fluence per pulse; repetition rate 120-1000Hz; 100-200ms pulse duration; and cumulative fluences ranging from 14 to 2200J/cm(2). Each window was irradiated with a 0.3mm beam diameter at one of nine power settings for 0.1, 0.5, or 1.0s. The pulp chamber temperature was measured with a microthermocouple. The irradiated teeth were evaluated by Polarized Light Microscopy (PLM) and Scanning Electron Microscopy (SEM). RESULTS: The pulp chamber temperature rise ranged from 0.5 to 19 degrees C depending on the location of the window and distance to pulp chamber. SEM revealed crystal fusion in both enamel and dentin at all cumulative fluences. At cumulative fluences of 40J/cm(2), 200 pulses/second and higher, measurable tissue loss was observed with PLM both in dentin and enamel. CONCLUSIONS: These results indicate there are threshold conditions above which pulsed CO2 laser light used for soft tissue surgery may cause detrimental changes to underlying oral hard tissue and to the pulp.
OBJECTIVES: The objective of this study was to evaluate the potential effects on underlying dental hard tissues of a high pulse rate carbon dioxide (CO2) laser that was designed for soft tissue surgery. METHODS: Eighteen extracted human teeth were sectioned longitudinally, cleaned, and varnished, leaving nine exposed windows on each: six on the coronal surface (enamel) and three on the root surface (cementum, dentin). The CO2 irradiation conditions used were: wave length 10.6 microm; 1.2-2.6J/cm(2) fluence per pulse; repetition rate 120-1000Hz; 100-200ms pulse duration; and cumulative fluences ranging from 14 to 2200J/cm(2). Each window was irradiated with a 0.3mm beam diameter at one of nine power settings for 0.1, 0.5, or 1.0s. The pulp chamber temperature was measured with a microthermocouple. The irradiated teeth were evaluated by Polarized Light Microscopy (PLM) and Scanning Electron Microscopy (SEM). RESULTS: The pulp chamber temperature rise ranged from 0.5 to 19 degrees C depending on the location of the window and distance to pulp chamber. SEM revealed crystal fusion in both enamel and dentin at all cumulative fluences. At cumulative fluences of 40J/cm(2), 200 pulses/second and higher, measurable tissue loss was observed with PLM both in dentin and enamel. CONCLUSIONS: These results indicate there are threshold conditions above which pulsed CO2 laser light used for soft tissue surgery may cause detrimental changes to underlying oral hard tissue and to the pulp.
Authors: Karen Müller Ramalho; Carlos de Paula Eduardo; Nicole Heussen; Rodney Garcia Rocha; Friedrich Lampert; Christian Apel; Marcella Esteves-Oliveira Journal: Lasers Med Sci Date: 2012-02-28 Impact factor: 3.161
Authors: Alberto González-Rodríguez; Juan de Dios López-González; Juan de Dios Luna del Castillo; Juan Villalba-Moreno Journal: Lasers Med Sci Date: 2010-04-27 Impact factor: 3.161
Authors: Verónica García-Sanz; Vanessa Paredes-Gallardo; Carlos Bellot-Arcís; Omel Mendoza-Yero; Carlos Doñate-Buendía; Javier Montero; Alberto Albaladejo Journal: PLoS One Date: 2017-10-19 Impact factor: 3.240