According to the American Association of Endodontics (Rivera & Walton 2008), there are five categories of crack:

• Craze lines: Only involving the enamel;
• Split tooth: Complete fracture through the tooth, usually centered mesial to distal;
• Fractured cusp: Usually non-centered and affect- ing one cusp;
• Cracked tooth: An incomplete fracture that extends from the crown to the subgingival area of the tooth; and
• Vertical Root Fracture (VRF):This may be sympto- matic or non- symptomatic.The majority of the VRFs are associated with root-filled teeth. It may be a complete or an incomplete fracture.