Surface temperature during cavity preparation on human tooth by Er:YAG laser irradiation

AbstractInadvertent Er:YAG laser irradiation occurs in dentistry and may harm restorative materials in teeth. The aim of this in vitro study was to quantify Er:YAG laser-induced damage to a nanohybrid composite in simulated clinical scenarios for inadvertent direct and indirect (reflection) laser irradiation. The simulation was performed by varying the output energy (OE;direct˃indirect) reaching the specimen and the operating distance (OD;direct˂indirect). Composite specimens were irradiated by an Er:YAG laser. The ablation threshold was determined and clinically relevant parameters were applied (n = 6 for each OE/OD combination) for direct (OE: 570 mJ/OD: 10 mm, OE: 190 mJ/OD: 10 mm) and indirect irradiation (OE: 466 mJ/OD: 15 mm, OE: 57 mJ/OD: 15 mm, OE: 155 mJ/OD: 15 mm, OE: 19 mJ/OD: 15 mm). The extent of damage in the form of craters was evaluated using a laser scanning microscope (LSM) and a conventional light microscope (LM). The ablation threshold was determined to be 2.6 J/cm2. The crater diameter showed the highest value (LM: 1075 ± 18 µm/LSM: 1082 ± 17 µm) for indirect irradiation (reflectant:dental mirror) (OE: 466 mJ/OD: 15 mm). The crater depth showed the highest and comparable value for direct (OE: 570 mJ/OD: 10 mm; LSM: 89 ± 2 µm) and indirect irradiation (OE: 466 mJ/OD: 15 mm; LSM: 90 ± 4 µm). For each OD, the crater diameter, depth, and volume increased with higher laser fluence. However, the OD—and thus the laser spot diameter—also had an enlarging effect. Thus, indirect irradiation (reflectant:dental mirror) with only 47% of the laser fluence of direct irradiation led to a larger diameter and a comparable depth. The three-dimensional extent of the crater was large enough to cause roughening, which may lead to plaque accumulation and encourage caries, gingivitis, and periodontitis under clinical conditions. Clinicians should be aware that reflected irradiation can still create such craters.

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Structural and Morphological Changes in Human Dentin after Ablative and Subablative Er:YAG Laser Irradiation

Journal of lasers in medical sciences ◽

10.15171/jlms.2016.15 ◽

2016 ◽

Vol 7 (2) ◽

pp. 86-91 ◽

Cited By ~ 8

Author(s):

Horieh Moosavi ◽

Sajedeh Ghorbanzadeh ◽

Farzaneh Ahrari

Keyword(s):

Laser Irradiation ◽

Er:Yag Laser ◽

Morphological Changes ◽

Human Dentin

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Pulp response to the Er:YAG laser in the cavity preparation

International Congress Series ◽

10.1016/s0531-5131(02)01335-3 ◽

2003 ◽

Vol 1248 ◽

pp. 37-43

Author(s):

Yoshito Hirai

Keyword(s):

Er:Yag Laser ◽

Cavity Preparation

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Human Dental Enamel and Dentin Structural Effects after Er:yag Laser Irradiation

The Journal of Contemporary Dental Practice ◽

10.5005/jp-journals-10024-1529 ◽

2014 ◽

Vol 15 (3) ◽

pp. 283-287 ◽

Cited By ~ 1

Author(s):

Mateus Rodrigues Tonetto ◽

Marcelo Ferrarezi de Andrade ◽

Shelon Cristina Souza Pinto ◽

Darlon Martins Lima ◽

José Roberto Cury Saad ◽

...

Keyword(s):

Laser Irradiation ◽

Soft Tissues ◽

Er:Yag Laser ◽

Laser System ◽

Dental Enamel ◽

Target Tissue ◽

Structural Effects ◽

Ablation Process ◽

Dental Tissues ◽

Laser Systems

ABSTRACT Ideally projected to be applied on soft tissues, infrared lasers were improved by restorative dentistry to be used in hard dental tissues cavity preparations — namely enamel and dentin. This paper evidentiates the relevant aspects of infrared Erbium laser's action mechanism and its effects, and characterizes the different effects deriving from the laser's beams emission. The criteria for use and selection of optimal parameters for the correct application of laser systems and influence of supporting factors on the process, such as water amount and its presence in the ablation process, protection exerted by the plasma shielding and structural factors, which are indispensable in dental tissues cavity preparation related to restorative technique, are subordinated to optical modifications caused by the interaction of the energy dissipated by these laser light emission systems in the targeted tissue substrate. Clinical relevance Differences in the action of infrared Erbium laser system in regard to the nature of the ablation process and variations on the morphological aspects observed in the superficial structure of the target tissue irradiated, may be correlated to the structural optical modifications of the substrate produced by an interaction of the energy propagated by laser systems. How to cite this article Lima DM, Tonetto MR, de Mendonça AAM, Elossais AA, Saad JRC, de Andrade MF, Pinto SCS, Bandéca MC. Human Dental Enamel and Dentin Structural Effects after Er:yag Laser Irradiation. J Contemp Dent Pract 2014;15(3):283-287.

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