Effect of different post-etching cleaning protocols on microshear bond strength of a lithium disilicate-reinforced ceramic, and SEM evaluation

Luiz Fernando Ortega, André Figueiredo Reis, José Augusto Rodrigues, Rose Yakushijin Kumagai, José Carlos Romanini-Junior e Caroline Ely

Objective: The aim of this study was to evaluate the effect of different post-etching cleaning (PEC) protocols on the microshear bond strength (SBS) of a lithium disilicate-reinforced ceramic and to characterize the PEC surface morphology by scanning electron microscopy (SEM). Methods: Twenty lithium disilicate-reinforced ceramic disks (IPS e.max Press, Ivoclar Vivadent) were used. Ceramic disks were serially wet-polished with SiC paper, etched with 10% hydrofluoric acid for 20 seconds and randomly assigned into four groups according to the PEC: control (air-water spray); H3PO4 (brushing with 37% phosphoric acid); UBA (ultrasonic bath in alcohol) and BA (brushing with alcohol). The restorative procedures were performed with an adhesive system (XP Bond) followed by a low-viscosity composite resin (SDR Flow). Four resin cylinders were bonded per ceramic disk (n = 5). The SBS test was performed and the failure pattern was evaluated by means of a stereomicroscope. SBS values were submitted to ANOVA and Tukey test ( = 5%). Ceramic surface characterization was performed by SEM. Results: The H3PO4 group showed the highest SBS values, but it was not different from the control and UBA groups (p > 0.05). The BA group presented lower SBS values when compared to the H3PO4 group (p < 0.05), but it was not significantly different from control and UBA groups (p > 0.05). A high number of adhesive failure was observed. SEM images showed a higher amount of debris for the BA group. Conclusions: All tested PEC presented SBS values similar to the control group. As regards SEM analysis, only the BA protocol presented a high amount of debris on the ceramic surface.

Keywords: Ceramics. Microshear bond strength. Hydrofluoric acid. Scanning electron microscopy.

How to cite: Ortega LF, Reis AF, Rodrigues JA, Kumagai RY, Romanini-Junior JC, Ely C. Effect of different post-etching cleaning protocols on microshear bond strength of a lithium disilicate-reinforced ceramic, and SEM evaluation. J Clin Dent Res. 2016 Apr-June;13(2):38-48. DOI: http://dx.doi.org/10.14436/2447-911x.13.2.038-048.oar

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