J Oral Laser Applications 10 (2010), No. 2-3 (20.12.2010)
Influence of Etching with Er,Cr:YSGG Laser on the Microtensile Bond Strength of Adhesives to Dentin
Geraldo-Martins, Vinicius R. / Armas-Vega, Ana del Carmen / Marques, Márcia M.
Purpose: The aim of this study was to investigate the bond strength of a composite to dentin treated with an Er,Cr:YSGG laser and different bonding systems.
Materials and Methods: Thirty-three extracted human teeth were longitudinally sectioned to obtain 65 specimens. After coronary dentin exposure and smear layer standardization, samples were divided into 5 groups (n = 13) and etched according to the Er,Cr:YSGG laser (20 Hz, 600 µm tip, 30%/30% air/water spray) parameters used: G1 (no laser), G2 (0.25 W), G3 (0.5 W), G4 (0.75 W), and G5 (1.0 W). Then, one sample per group was prepared for SEM observation. The remaining specimens were divided in two subgroups for the application of adhesive systems (Single Bond [3M] and Clearfil SE Bond [Kuraray]) followed by the application of a 5-mm buildup of Z250. The microtensile bond strength (µTBS) was determined after 24 h of storage in water at 37°C. The obtained data were compared using the two-way ANOVA and Tukey's test (p <= 0.05).
Results: No statistical differences were found among the samples treated with Single Bond. The µTBS was significantly lower for samples treated with Clearfil and laser with powers over 0.75 W. SEM observation showed that the morphological characteristics of the irradiated dentin were similar for all parameters used.
Conclusion: The bonding effectiveness of adhesives to laser-irradiated dentin may be influenced not only by the structural substrate alterations induced by the laser, but also by the characteristics of the adhesive employed.
Keywords: laser, Er,Cr:YSGG, dentin, bond strength, adhesives, composite resin