Visual inspection of the crown of the tooth allows the clinician to take note of any deviation from normal tooth color and any abnormalities in crown structure, whether congenital or acquired.
Enamel and/or dentin fractures can suggest that a tooth has been traumatized and may undergo irreversible pulpitis (Figure 1, above and Figure 2, below). Any tooth with a complicated crown fracture will become nonvital over time due to oral bacterial colonization of the pulp. Carious lesions can also irritate the pulp and cause pulpitis.
Extrinsic staining is limited to tooth enamel and can typically be removed via scaling and polishing. Intrinsic staining occurs in the dentin, can be systemic or localized, and may indicate a nonvital tooth. A common cause of localized intrinsic staining is intrapulpal hemorrhage with necrosis that occurs when a tooth is traumatized.1 The byproducts of hemorrhage can penetrate the dentin tubules and cause discoloration of the dentin. The discoloration can change over time as the byproducts break down in the tubules. Teeth can initially appear pink to purple and can eventually become gray (Figure 3). Intrinsic staining from hemorrhage or necrosis indicates that significant trauma to the pulp has occurred and pulpitis is or was present.
The shape of the crown and/or root can also give insight into any developmental abnormalities of the tooth that can potentially affect vitality (Figures 4 and 5).