SEM Evaluation of the Hybrid Layer After Cavity Preparation with Er:YAG Laser

Abstract

SUMMARYThis study compared the thickness of the hybrid layer formed using Scotchbond Multi-Purpose Plus, Single Bond 2, Prime & Bond 2.1 and Xeno III on a dentin surface prepared with a diamond bur in a high speed handpiece or prepared with an Er:YAG laser used with two parameters of pulse energy (200 and 400 mJ) and two parameters of frequency (4 and 6 Hz). Flat dentin surfaces obtained from 20 human third molars were treated with the two methods and were then prepared with the dentin adhesive systems according to the manufacturers' instructions. After a layer of composite was applied, the specimens were sectioned, flattened, polished and prepared for Scanning Electronic Microscopy observation. Five different measurements of the hybrid layer thickness were obtained along the bonded surface in each specimen. The results were statistically analyzed using Analysis of Variance and Student-Newman-Keuls tests (p≤0.05). When analyzing the hybrid layer thickness and comparing the cavity preparation method, four groups were formed: Group I (diamond bur) > Group II (Laser 200 mJ/4 Hz) = Group III (Laser 200 mJ/6 Hz) > Group IV (Laser 400 mJ/4 Hz) > Group V (Laser 400 mJ/6 Hz). When comparing the dentin adhesive systems, there were no statistically significant differences. These results showed that the four tested dentin adhesive systems produced a 2.90 ± 1.71 µm hybrid layer in dentin prepared with a diamond bur. This hybrid layer was regu- MO Barceleiro • KRHC Dias • HX Sales BC Silva • CG Barceleiro Clinical RelevanceThe thinner, irregular hybrid layer found when a cavity is prepared with the Er:YAG laser may have a negative effect on bonding. 295 lar and routinely found. In the laser groups, the dentin adhesive systems produced hybrid layers ranging from 0.41 ± 1.00 µm to 2.06 ± 2.49 µm, which were very irregular and not routinely found. It was also concluded that the Er:YAG laser, with the parameters used in this experiment, has a negative influence on the formation of a hybrid layer and cavity preparation methods influence formation of the hybrid layer.

Influence of Er:YAG laser irradiation settings on dentin‐adhesive interfacial ultramorphology and dentin bond strength

“…The effects of Er:YAG laser irradiation on bond strength is controversial, reflecting the differences of experiments, adhesives used, laser settings and bond strength tests. Results from various studies have reported that the laser‐treated dentin bond strength was significantly higher than those using conventional methods (such as burs) to prepare the hard dental tissues (Aranha et al, 2007; Barceleiro et al, 2008; Comba et al, 2019; Esteves‐Oliveira et al, 2007; Ghiggi et al, 2010; Oliveira et al, 2007; Oliveira et al, 2010; Ramos et al, 2014; Ribeiro et al, 2013; Trajtenberg et al, 2004; Yazici et al, 2010; Zhang & Jiang, 2020), while other results showed no laser effect or bond strength decrease (Amaral et al, 2008; Comba et al, 2019; Esteves‐Oliveira et al, 2007; Oliveira et al, 2013; Ramos et al, 2014; Tokonabe et al, 1999; Yazici et al, 2010).…”

“…to prepare the hard dental tissues (Aranha et al, 2007;Barceleiro et al, 2008;Comba et al, 2019;Esteves-Oliveira et al, 2007;Ghiggi et al, 2010;Oliveira et al, 2007;Oliveira et al, 2010;Ramos et al, 2014;Ribeiro et al, 2013;Trajtenberg et al, 2004;Yazici et al, 2010;Zhang & Jiang, 2020), while other results showed no laser effect or bond strength decrease (Amaral et al, 2008;Comba et al, 2019;Esteves-Oliveira et al, 2007;Oliveira et al, 2013;Ramos et al, 2014;Tokonabe et al, 1999;Yazici et al, 2010).…”

Morphological and Chemical Comparative Analysis of The Human and Bovine Dentin–Adhesive Layer

“…Upon completion, sections were washed with distilled water and ultrasonicated for 10 min. They were then decalcified with 37% phosphoric acid for 10 s, rinsed with distilled water and deproteinized in 3% sodium hypochlorite for 60 s (Ferrari et al, 1999; De Barceleiro et al, 2008). Specimens were then rinsed with distilled water, air dried and dehydrated by immersion in ascending grades of ethanol solutions (30, 50, 70, and 90%) with a dehydration time of 5 min in each solution.…”

The influence of experimental silane primers on dentin bond strength and morphology: A laboratory and finite element analysis study

“…[11][12][13] Several applications, such as self-etching bonding agents, acid etching, primer application, and Er:YAG laser, have been introduced to control the formation and morphology of the HL. [14][15][16] Variations in protocols and conditions such as in the material composition, pH, concentration of primers, wettability, volume of water, and viscosity of the composite resin and primer might affect the thickness of the HL. 17 The thickness of the HL is reported to range from less than 1 mm for all-in-1 systems to 5 mm for conventional systems.…”