Fig. 2
From: Effect of aqueous environment on wear resistance of dental glass–ceramics
SEM images under high magnification of the as-worn surfaces developed in different environmental conditions: LD in a wet environment without ultrasonic cleaning (A) and after removal of the tribofilm with ultrasonic cleaning as revealed in C and E; LD in a dry environment without ultrasonic cleaning (B) and after ultrasonic cleaning (D) and (F); LEU in a wet environment (G); LEU in a dry environment (H); the white arrow indicates needle-like hole; the black arrow indicates the small micropores along the edge of LD crystals