These areas of tooth loss are often caused by clenching or grinding the teeth, creating enough load to flex the tooth slightly, popping off the thin layer of enamel over this area of the tooth. Other causes include the consumption of soft drinks (including diet drinks) that are acidic.
When small, these defects are harmless. However, allowing them to become larger can endanger the tooth, allowing it to fracture more easily, or even expose the pulp (nerve).
Normally, a bonding type material can be used, often without requiring the use of local anesthetic. This is a relatively simple dental procedure.