Evaluation of carbon dioxide laser irradiation associated with calcium hydroxide in the treatment of dentinal hypersensitivity. A preliminary study

Abstract

Attempts have been made to treat dentinal hypersensitivity by sealing exposed dentinal tubules, and the carbon dioxide (CO(2)) laser has been shown to have a sealing effect on dentinal surfaces. The purpose of this study was to analyze the morphological ultra-structure and temperature change after CO(2) laser irradiation of dentin. Fourteen human third molars were selected and cleaned. An area was delimited, and the samples were randomly divided into seven groups: Group 1 (G1): control; G2, calcium hydroxide paste (CA) + CO(2) laser (L) (0.5 W/63,69 W/cm(2)); G3, CA + L (1 W/125,38 W/cm(2)); G4, CA + L (1.5 W/191,08 W/cm(2)); G5, L (0.5 W); G6, L (1 W); G7, L (1.5 W). All irradiation was performed in unfocused mode. The electron micrographs were analyzed by three observers. For temperature analysis, a thermocouple was used. Data were subjected to statistical analysis. The Kruskal-Wallis non-parametric test showed statistical differences between the groups (P < 0.05). For the two by two comparisons, all groups treated with calcium hydroxide paste presented significantly higher mean scores. In the groups treated by CO(2) laser only, fusion, re-crystallization, cracks and carbonization were observed. A change of 1 ± 5°C was noted in the temperature. Under the limitation of an in vitro study, and with the protocols used, we concluded that CO(2) laser is safe to use for the establishment of partial fusion and re-solidification of the dentinal surface.

Comparative Evaluation of the Effects of Nd:YAG Laser and a Desensitizer Agent on the Treatment of Dentin Hypersensitivity: A Clinical Study

“…[10][11][12][13][14][15][16][17][18] Among them, the mode of action of Nd:YAG laser is highlighted. This equipment has been used since 1985 and has shown the ability to obliterate the tubules through a process called ''melting and re-solidification,'' without causing pulp damage or cracks when used with an appropriate protocol.…”

Laser-assisted treatment of dentinal hypersensitivity: a literature review

“…Also in this section the effectiveness of CO2 laser will be debated, despite the paucity of literature on its individual use in last years. Romano et al (38) indeed stress the sealing power of the CO2 laser. Subjects have been divided into 7 groups and treated with only laser (0,5-1-1,5 W) or with laser and a calcium hydroxide paste.…”

Heat Generation and Transfer on Biological Tissues Due to High-Intensity Laser Irradiation

“…These thermocouples had 0.05 mm diameter probe and were sensitive to temperature variations between 0.1 °C and 100 °C. The temperature sensitive end of the probe was placed at the closest distance to the area to be irradiated, and its location was controlled radiographically for each sample (Romano et al, 2011). The thermocouple apparatus was connected to an analogue-to-digital converter (SR lock-in amplifier, Stanford Research System, USA) linked to a computer, and time and temperature data were recorded at sampling rate of 20 Hz, with temperature resolution of 0.1 o C. During laser irradiation, samples were fixed and immersed in a water-filled heating circulator at standardized temperature of 37 °C, with only the coronal part of the tooth not being submerged in order to simulate body temperature in the oral environment.…”