Root Fracture Risk Calculator

This calculator estimates vertical root fracture (VRF) risk for an endodontically treated tooth from five factors: remaining dentin thickness at the thinnest cervical wall, the final canal enlargement size, whether a post is present, occlusal loading, and tooth type. Remaining dentin thickness is the single largest driver of the risk score because it is the primary structural predictor cited for VRF — walls thinner than about 1mm are treated as substantially higher risk than walls over 2mm, reflecting how little dentin is left to resist functional loading forces. Canal enlargement adds risk because a wider final preparation removes more dentin and thins the remaining canal walls; a post adds risk because post space preparation and the post itself further weaken the root and can act as a stress riser; heavy occlusal loading (bruxism/parafunction) and premolar tooth type (the tooth type most often associated with VRF in the literature) both add smaller risk increments.

The combined score maps to a risk category and an estimated 5-year survival probability, and separately flags whether full cuspal coverage is recommended. This is a structural risk index built on commonly cited VRF risk factors, not a diagnostic tool — it cannot detect an existing fracture, and only cone-beam CT or direct clinical/radiographic examination (or in some cases exploratory surgery) can confirm whether a fracture is already present.