Permeability, morphologic and temperature changes of canal dentine walls induced by Nd: YAG, CO₂ and argon lasers

Abstract

The permeability, temperature and morphologic changes of the wall of the root canal induced by Nd:YAG, CO2 and argon lasers were studied. The changes were evaluated according to the presence or absence of a smear layer. Root canals of 140 human single-rooted teeth were enlarged using a step-back technique. Permeability was evaluated by the extent of methylene blue dye penetration into the tubules. Temperature changes were measured using a thermovision system, and morphological changes were evaluated by scanning electron microscopy. Laser energy was delivered into the canal by means of a flexible optical fibre or metal tip. There were statistically significant differences in permeability between lased groups with and without a smear layer in the cervical third of the root canal following lasing. In the middle third of the root canal, all three laser types induced permeability increases in groups with a smear layer. In the apical third, statistically significantly decreases in permeability were observed among CO2 laser and Nd:YAG compared with control group (P < 0.01). Rises in temperature ranged from a minimum of +10.1 degrees C (CO2 laser) to a maximum of +54.8 degrees C (argon laser). All three laser devices appeared capable of producing a glazed-like surface and craters.

Investigation of Coronal Leakage of Root Fillings After Smear-Layer Removal with EDTA or Nd:YAG Lasing Through Capillary-Flow Porometry

“…[1][2][3][4][5][6][7]13 These changes are confirmed on the SEM images in this study in Group 3 with Nd:YAG lasing, after the NaOCl supported root-canal preparation (Fig. 3a).…”

“…An abundant number of studies have shown that direct Nd:YAG laser irradiation on dentin surfaces produces melting and recrystallization, which, in turn, causes a reduction in dentin permeability. [1][2][3][4][5][6][7] In view of ''dentin melting'' 8 and ''reduction of the permeability of dentin'', 3 a number of investigators have attempted to improve the quality of the apical seal and thus to reduce apical leakage after apical filling. [9][10][11][12][13][14][15] It is clear from these studies that morphologic changes after Nd:YAG laser irradiation can influence the marginal sealing of the root-canal obturation.…”

Longitudinal Study on the Influence of Nd:YAG Laser Irradiation on Microleakage Associated with Two Filling Techniques

“…1 A variety of studies have shown that direct Nd:YAG laser irradiation on dentin surfaces produces melting and recrystallization which, in turn, causes a reduction in dentin permeability. [2][3][4][5][6][7][8] In view of ''dentin melting'' 9 and ''reduction of the permeability of dentin'' 4 a number of investigators have attempted to improve the quality of the apical seal and thus reduce apical leakage following apical filling. [10][11][12][13][14][15][16] Apparently, morphological changes following Nd:YAG laser irradiation can influence the marginal sealing of the root canal obturations.…”

Dental Lasers and Application Fields in Endodontics

“…Marketed solely for dental use, these are the first true pulse lasers with a near infrared wavelength of 1064 nm (3). Primarily used for Öz 1971'de Weichman tarafından endodonti alanında ilk lazer uygulanmasının ardından, lazer teknolojisinin hızlı gelişimi ile yeni lazer cihazları ile ilgili çalışmalar hız kazanmıştır.…”