Dentinal tubule occlusion using Er:YAG Laser: an in vitro study

Abstract

Objectives: We analyzed the effects of the Er:YAG laser used with different parameters on dentinal tubule (DT) occlusion, intrapulpal temperature and pulp tissue morphology in order to determine the optimal parameters for treating dentin hypersensitivity. Methodology: Dentin specimens prepared from 36 extracted human third molars were randomized into six groups according to the treatment method (n=6 each): control (A); Gluma desensitizer (B); and Er:YAG laser treatment at 0.5 W , 167 J/cm2 (50 mJ, 10 Hz) (C), 1 W , 334 J/cm2 (50 mJ, 20 Hz) (D), 2 W , 668 J/cm2 (100 mJ, 20 Hz) (E), and 4 W and 1336 J/cm2 (200 mJ, 20 Hz) (F). Treatment-induced morphological changes of the dentin surfaces were assessed using scanning electron microscopy (SEM) to find parameters showing optimal dentin tubule occluding efficacy. To further verify the safety of these parameters (0.5 W, 167 J/cm 2 ), intrapulpal temperature changes were recorded during laser irradiation, and morphological alterations of the dental pulp tissue were observed with an upright microscope. Results: Er:YAG laser irradiation at 0.5 W (167 J/cm 2 ) were found to be superior in DT occlusion, with an exposure rate significantly lower than those in the other groups (P<0.05). Intrapulpal temperature changes induced by Er:YAG laser irradiation at 0.5 W (167 J/ cm2) with (G) and without (H) water and air cooling were demonstrated to be below the threshold. Also, no significant morphological alterations of the pulp and odontoblasts were observed after irradiation. Conclusion: Therefore, 0.5 W (167 J/cm 2 ) is a suitable parameter for Er:YAG laser to occlude DTs, and it is safe to the pulp tissue.

The Efficacy of Different Laser Applications on Dentin Sealing in Preventing Discoloration Induced by Mineral Trioxide Aggregate

“…In the treatment of dentin hypersensitivity, various lasers are currently employed, including Nd:YAG, Er:YAG, Er Cr:YSGG, and diode lasers [ 35 ]. The effectiveness of Nd:YAG lasers in providing efficient tubule occlusion and penetration depth for the treatment of DH was reported [ 36 ].…”

“…It is believed that the effectiveness of the Er:YAG laser in occluding dentin tubules is due to the absorption of laser irradiation by water molecules within hydroxyapatite, leading to dentin ablation and subsequently causing the melting and recrystallization of the dentin [ 39 , 40 ]. Zhuang et al [ 35 ] investigated the effect of Er:YAG laser application on dentin tubule occlusion and intrapulpal temperature increase and its impact on pulp using different parameters (0.5 W/50 mJ/10 Hz, 1 W/50 mJ/20 Hz, 2 W/100 mJ/20 Hz, and 4 W/200 mJ/20 Hz). As a result, they found the 0.5 W and 50 mJ setting to be effective for dentin tubule occlusion.…”

“…As a result, they found the 0.5 W and 50 mJ setting to be effective for dentin tubule occlusion. Therefore, in this study, the Er:YAG laser was used with parameters of 0.5 W, 50 mJ, and 10 Hz [ 35 ].…”

A Comparative Analysis of the Occluding Effects on Dentinal Tubules With the Use of Er:YAG Laser and a Commercially Available Desensitizing Agent: An In Vitro Scanning Electron Microscopic Study

“…They were initially immersed in a solution of 2.5% glutaraldehyde (Cidex, Johnson & Johnson India, Mumbai, India) for a duration of 12 hours at a temperature of 4 °C. This immersion served to effectively conserve the samples and stabilize the dentinal tubules prior to their examination through SEM [ 12 ]. Following this preservation step, a chemical dehydration procedure was carried out.…”

Current Applications and Future Directions of Lasers in Endodontics: A Narrative Review

“…Meanwhile, the assessment of the intrapulpal temperature stabilization and pulp tissue morphological invariability was also conducted. In addition, the extracted human molars after Er:YAG laser irradiation at 0.5 W (167 J/cm 2 ) showed superior dentin tubule occlusion, less intrapulpal temperature change, and hardly any morphological alterations of the pulps [ 104 ]. The dentine of different thicknesses was irradiated with a Nd:YAP laser in an ex vivo study; whilst conducting this, they found that a Nd:YAP laser at a PD of 356 W/cm 2 had a significant effect on the diameter change in dentinal tubule orifices and caused less of an increase in temperature [ 25 ].…”