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)](https://thehybridlayer.com/wp-content/uploads/2022/01/peripheral-rim-fracture.jpg)
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.