A chipped tooth into enamel or dentin is common. 

Be sure to look for nerve exposure (appearance of a red dot).

If no nerve exposure:

Keep the tooth clean to prevent plaque build-up.  Smearing fluoride toothpaste onto exposed dentin can help decrease sensitivity.  Schedule a visit with us; typical treatment involves a white restoration to cover the area where the tooth broke off.

Nerve exposure noted:

It is best to cover the area of exposed nerve ASAP.  Please call us or report to the ER.  Typical treatment involves disinfection and covering the exposed nerve with a particular medicament.