Sometimes a tooth breaks upon impact such as accidentally chewing a pit or being hit in the face usually a small fracture begins at the edge of the tooth then deepens over time as you clench, grind or chew.

Some people are more susceptible than others to having a cracked tooth. Factors that are more likely to lead to a cracked tooth are:

• Deep fillings that leave thin amounts of tooth structure
• Sports such as hockey, football and boxing that have a high risk of facial trauma
• People who grind their teeth or have strong chewing muscles
• People with destructive habits like chewing ice or opening things with their teeth

Your dentist will make recommendations to minimize your risk of a
cracked tooth.
Here are some things that may be recommended:

• Have crowns placed to cover weak cusps of teeth
• Have your bite adjusted by your dentist
• Have old silver fillings replaced
• Do not chew ice or use teeth to open things
• Wear a night time grinding appliance
• Wear a sports guard

It is likely that the crack will continue to deepen and eventually the tooth may become painful to chewing or pieces may break off it. Sometimes the tooth may crack completely in half, at which point it must be extracted. Other times the crack goes into the nerve and a root canal treatment may be necessary to save the tooth.