Longitudinal tooth cracks and fractures: an update and review

Abstract

The purpose of this updated review is to further discuss the diagnostic and treatment challenges related to tooth cracks and fractures that occur primarily in the vertical plane, that is, the long axis of the crown and/or root. This includes when and how to identify and determine the category and the extent of the fracture, when a coronally reinforcing restoration should be placed, when root canal treatment is needed, and when a tooth or root should be extracted based on the location and extent of the fracture. The term “longitudinal” is used because they usually represent vertical extensions of cracks or fractures over distance and time. These often present problems with diagnosis and treatment, but should be considered as findings and not as a diagnosis per se. They are pathways for bacteria that may induce pulpal and periapical inflammation or disease. Longitudinal fractures are divided into five definitive classifications from generally least to most severe: (i) craze line; (ii) fractured cusp; (iii) cracked tooth; (iv) split tooth; and (v) vertical root fracture. These differ but have frequently been confused or combined in clinical articles, creating misunderstanding and resulting in incorrect diagnosis and inappropriate treatment. These classifications have been devised to provide global definitions that researchers and clinicians can use to eliminate this confusion. This review is subdivided into these five classifications as to incidence, pathogenesis, clinical features, etiologies, diagnosis, treatment, prognosis, and prevention.