Effect of different power parameters of Er,Cr:YSGG laser on human dentine

Abstract

The aim of this work was to determine the optimal power setting of an Er,Cr:YSGG laser for cutting human dentine to produce a surface that remains suitable as a foundation on which to build and bond a dental restoration. The cutting efficiency and resulting microhardness of the dentine were evaluated for various laser power settings, and representative samples were examined by SEM. The microhardness of the dentine was significantly reduced by 30-50% (p < 0.05, paired t test) after laser irradiation, irrespective of the power setting used. The mean ablation efficiency increased in proportion to the power setting of the laser. Although the laser power setting did not affect the extent of reduction in microhardness, it did affect the microstructure of human dentine.

Effect of Er,Cr:YSGG and Er:YAG laser irradiation on the adhesion of blood components on the root surface and on root morphology

“…Dentin is formed by a mix of tubular, peritubular and intertubular tissue holding different concentrations of water, thus leading to an unequal ablation. 6 We observed no differences between the degrees of adhesion of blood components on the surfaces irradiated with the Er:YAG laser and on those treated with curettes. This proves that irradiation with the Er:YAG laser does not lead to a root surface more biocompatible with blood cells and fibrin network than that obtained with the conventional manual scaling treatment.…”

“…This type of ablation occurs owing to the sudden evaporation of water from the amorphous interprismatic substance, which causes microbursts of the dental tissue and the elimination of hydroxyapatite crystals at temperatures below their melting point, without causing thermal damage to the dentin tissue. 5,6 The roughness observed in the samples may be explained by the heterogeneity of the dentin tissue. Dentin is formed by a mix of tubular, peritubular and intertubular tissue holding different concentrations of water, thus leading to an unequal ablation.…”

“…matic substance, removing hydroxyapatite crystals at a temperature below its melting point (~1,200°C). 5,6 Owing to this effect, these lasers abrade hard tissue without causing thermal damage. Some studies have shown that irradiation of root surfaces using Er:YAG lasers does not promote the formation of a smear layer.…”

Effects of different types of adhesive systems on the microleakage of compomer restorations in Class V cavities prepared by Er,Cr:YSGG laser in primary teeth

“…In contrast, the laserprepared surface was clear, had no smear layer and had a prismatic structure. Ekworapoj et al 66) ablated dentin by using Er,Cr:YSGG laser with different power levels (3, 3.5, 4, 4.5 W; 20 Hz; air and water cooling) and used SEM to observe the microstructures of ablated dentin. At all power levels, the smear layer was eliminated, peritubular dentin was prominently observed, and dentin tubules were completely opened 66) .…”

In vitro microleakage of class v composite restorations prepared by Er,Cr:YSGG laser and carbide bur

“…The micromorphology pattern of the dentin surface is also different according to the method used. Laser irradiation is mostly absorbed by intertubular dentin due to its conciseness in water and organic components, while acidetching influences the most calcified part of dentin, which is peritubular dentin 42 . According to Esteves-Oliveira et etch systems being not sufficient to decalcify enamel.…”