Subablative Er:YAG Laser Effect on Enamel Demineralization

Abstract

Objectives: To characterize the cariostatic potential of a low-energy Er:YAG laser treatment. Methods: Twelve sound premolars were selected. Two 2 × 1 mm windows were created on each tooth and randomly assigned to L₁ and L₂ groups. Three sites in each window were chosen with the middle site as the control and the left and right ones receiving Er:YAG laser treatment of 5.1 J/cm² (L₁) or 2.0 J/cm² (L₂), respectively. The teeth were further subjected to 4-day pH cycling to create caries-like lesions. After mineral quantification using a micro-computed tomography scanner, the preventive effects (ΔML = mineral loss of the control area minus that of the lased area) of L₁ and L₂ treatments were calculated based on the difference in the gray value of the control and lased sites. Results: Significant inhibitory effects of L₁ and L₂ on enamel demineralization were demonstrated (both p ≤ 0.001), with the L₁ treatment having a greater effect (45.2%) than the L₂ treatment (25.2%, p = 0.004). Conclusions: Subablative low-energy Er:YAG laser irradiation can significantly prevent enamel demineralization potentially through the retardation of enamel diffusion. This study confirmed that high-energy laser treatment, which may damage the peripheral and underlying tissues, may not be needed for caries prevention.

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

“…When using Er:YAG laser with subablative parameters, it is very important to use the lowest energy level because higher energies produce microcracks and damage the peripheral and underlying tissues. 18 Therefore, subablative irradiation in this study was carried out with a very low energy level. Considering the promising outcomes of this study, cavity preparation with Er:YAG laser could be considered as a viable alternative to the conventional application of high speed handpiece and burs, which enhances the mechanical and compositional properties of lased dentin, especially when combined by subablative irradiation.…”

“…17 demonstrated some increase in acid resistance following subablative irradiation with erbium family lasers, which failed to achieve significance in the statistical analysis, whereas Liu et al 18 and Castellan et al 19 reported a significant prevention of enamel demineralization. Morphological examination of surfaces treated by the Er:YAG laser revealed roughness and irregularities which provided microretentive patterns 12,[20][21][22][23] and at the cavity walls, there was almost no smear layer.…”

Effects of Different Combinations of Er:YAG Laser-Adhesives on Enamel Demineralization and Bracket Bond Strength

“…Then, the samples were washed with deionized water and immersed in the remineralization solution (pH = 7.0), consisting of 0.15 mol/L potassium chloride, 1.5 mmol/L calcium (CaCl 2 ), and 0.9 mmol/L phosphate ions (NaH 2 PO 4, ). 11,12 Both the demineralization and remineralization solutions were changed daily. The teeth were cycled separately in individual glass containers throughout the 14-day process, then stored in deionized water until the micro-CT scanning.…”

“…8,9 Moreover, laser irradiation produced acid-resistant surfaces by altering the calcium to phosphate ratio and promoting the formation of less soluble compounds. [10][11][12] These specific characteristics of Er:YAG laser suggest the question of whether the laser etching of enamel could be effective in preventing enamel demineralization around brackets when this technique is used routinely in clinical practice. However, it should be noted that successful orthodontic treatment depends upon the bond strengths of the orthodontic brackets.dissimilar adhesive systems.…”

Chemical Changes of Enamel Produced by Sodium Fluoride, Hydroxyapatite, Er:YAG Laser, and Combined Treatments

“…Reports indicate that the structural composition in enamel after irradiation with an Er:YAG laser can favor acid resistance due to the loss of carbonate [16][17][18][19][20][21]. A combination of fluoride and laser treatments can also make the enamel more resistant to acid than either treatment alone [19,20,[22][23][24][25][26].…”