The purpose of this study was to evaluate the effect of Er,Cr:YSGG laser irradiation and/ or acid etching on the micro-shear bond strength (µSBS) of two different dual-cured resin cements to human enamel. 24 intact, extracted molars were sectioned longitudinally and randomly divided into three subgroups according to three surface pretreatment methods:(1) Er,Cr:YSGG laser (Waterlase MD, Biolase) irradiation was used with a power setting of 2 W (55% water and 65% air), and a repetition rate of 20 Hz for 10 s; (2) 37% phosphoric acid application for 20 s;(3) Re-etching with phosphoric acid for 20 s after the Er,Cr:YSGG laser irradiation as in group1.12 enamel discs for each of the resin cements (Panavia F2.0 and Variolink N) were prepared and three cylinders of resin cements were bonded to each enamel surface (n = 12). A microshear bond test (EZ-test-500 N) was used at a cross-head speed of 1 mm min −1 to determine the µSBS. One-way analysis of the variance and Tukey post-hoc tests at the 95% confidence level were used to analyze the µSBS values. Panavia F2.0 verified significantly higher µSBS values than Variolink N (p < 0.05) for all the tested surface pretreatment methods. The combination of laser and acid etching on enamel produced higher µSBS values for bonding both resin cements than the use of acid or laser irradiation alone. The combination of the Er,Cr:YSGG laser and phosphoric acid etching of the enamel for the cementation of indirect restorations with Variolink N and Panavia F2.0 produced better µSBS values to enamel than the use of phosphoric acid or Er,Cr:YSGG laser etching alone, holding the potential to become a highly attractive method for routine use.

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