Ellis Classification of Dental Fractures

Ellis I

Includes crown fractures that extend only through the enamel.
Teeth are usually nontender, and without visible color change, but have rough edges.

Ellis II

Fractures that involve the enamel and dentin layers.
Teeth are typically sensitive to cold, hot, touch and/or air exposure. A yellow layer of dentin may be visible on examination

Ellis III

Involve the enamel, dentin, and pulp layers.
Teeth are extremely sensitive, and have a visible area of pink, red, or even blood at the center of the tooth.