Etch pits could form on an exposed surface of a crystal when the crystal is exposed to an etching environment or chemicals. Due to different dissolution rates along various crystalline directions in a crystal, the dissolution process is anisotropic; hence, etch pits usually have a regular shape....
The length of the lowest reinforcement layer at the base of the abutment is equal to 3.6 m (0.43 H), which is more than the width of the base (B = 3.1 m, excluding the block face) but more than the minimum base-to-height (B/H) ratio (excluding the block face) of 0.3. The ...