Enamel infractions are microcracks seen within the dental enamel of a tooth

Tooth

Teeth are small, calcified, whitish structures found in the jaws of many vertebrates that are used to break down food. Some animals, particularly carnivores, also use teeth for hunting or for defensive purposes. The roots of teeth are embedded in the Mandible bone or the Maxillary bone and are...

. They are commonly the result of dental trauma

Dental trauma

Dental trauma refers to trauma to the face, mouth, and especially the teeth lips and periodontium. The study of dental trauma is called dental traumatology.- Types :* Tooth fractures**Enamel infraction**Enamel fracture**Enamel-dentine fracture...

 to the brittle enamel, which remains adherent to the underlying dentine. They can be seen more clearly when transillumination

Transillumination

Transillumination is the technique of sample illumination by transmission of light through the sample. Transillumination is used in a variety of methods of imaging.-Microscopy:...

 is used.

Enamel infractions are found more often in older teeth, as the accumulated trauma is greatest.
Enamel infractions can also be found as a result of iatrogenic damage inadvertently caused by instrumentation during dental treatments.