Effect of post etching cleansing on surface microstructure, surface topography, and microshear bond strength of lithium disilicate.

AIM

This study assessed the effect of postetch cleansing on the surface microstructure, surface topography, and microshear bond strength (μSBS) of lithium disilicate and the resin cement.

SETTING AND DESIGN

analytical study.

MATERIALS AND METHODS

Fifteen discs (10 mm diameter and 2 mm thickness) were fabricated from highly translucent lithium disilicate IPS Emax 2 ceramic (Ivoclar Vivadent, Schaan, Liechtenstein). Four resin cement (RelyX Ultimate, 3M ESPE) cylinders (0.9 mm diameter and 4 mm high) were placed on each ceramic disc (total = 60). The samples were divided into three groups based on the surface treatment of the ceramic discs (20 resin cement cylinders on 5 discs in each group). Group I (HF) (control) etched with 9.6% HF with no postetch cleansing, Group II (HFP) etched with 9.6% HF for 20 s followed by rinsing with water and postetching cleansing with 37% phosphoric acid, and Group III (HFPU) etched with 9.6% HF followed by active application of 37% phosphoric acid followed by postetch cleansing in ultrasonic bath for 5 min. μSBS of resin cement to ceramic surfaces was tested following a standard protocol. Surface roughness was evaluated using an atomic force microscope. Surface topography and elemental analysis were analyzed using SEM/EDX. Mode of failure was also assessed.

STATISTICAL ANALYSIS USED

The data were analysed using one way analysis of variance and post hoc tukeys test.

RESULTS

The μSBS were found to be highest for Group III (HFPU), followed by Group II (HFP) followed by Group I (HF) and were statistically significant. There was a difference in the surface topography and surface microstructure between the three groups. Mode of failure was predominantly adhesive.

CONCLUSION

The μSBS, surface topography, and surface microstructure were found to be superior in the groups, in which postetch cleansing was done as compared to the control in which no postetch cleansing was done.