Round polymer bur for excavation. In collaboration with Prof. Dr. Kunzelmann from Ludwig Maximilians University in Munich, we have developed a round polymer instrument based on the concept of self-limiting caries therapy. The specific hardness of the material that composes the PolyBur P1 bur prevents over-excavation, as the soft carious substance will automatically lose its cutting edge upon contact with hard, healthy dentin. The PolyBur bur is self-limiting!