Extrinsic dental stain caused by chlorhexidine and other denaturing agents

Experiments were performed in a standardized rabbit model for examination of the potential of chlorhexidine and other denaturing agents to induce dental stain together with ferric ions. The studies supported the view that denaturation may be a major aspect of the mechanism of stain formation and that iron sulphide may be one important cause for extrinsic dental stain. Analytical microprobe analysis showed high amounts of Fe and S in the stain. The stain formation could be inhibited by SnF2, possibly by a red-ox reaction. Established stain could be removed by an oxidizing agent.