As a dental hygienist I know that staining occurs with chlorhexidine use; what I want to know is WHY the staining occurs. What is the mechanism that happens. Is it a type of chemical reaction?

I think its from increased calculus production, and subsequent discoloration of that calculus by the chemical in peridex

I actually got the answer from an alternate source; the University of San Francisco... Chlorhexidine absorbs to biofilms and causes a modification of the biolfilm properties which allows further absorption of extrinsic stains.