Summary – What is a Peripheral Rim Fracture (PRF)?

If a traditional cavity is prepared with an isthmus width >2 mm, the tooth is no longer connected in a biomimetic way. The tooth can flex in a range of around 200 microns which results in stress concentration. Fracture resistance decreases and the marginal ridges are more likely to crack, leading to Peripheral Rim Fractures (PRF).

Photo showing a PRF (Peripheral Rim Fracture)
Fig 1. Clinical example of a Peripheral Rim Fracture (PRF).
Photo credit: Dr Pete Butkus

Learn More…

To learn more about Peripheral Rim Fractures in relation to structural compromises and micromovements, see Lesson 2 of the Six Lessons Approach to Biomimetic Dentistry below.