Chemical plaque control and extrinsic discoloration of teeth.

Extrinsic discoloration of teeth is an unwanted side-effect in connection with the use of the chemical plaque-preventive agent chlorhexidine. Individual differences in discoloration tendency have, however, been observed. In order to study the nature of these extrinsic discolorations a selection of 3 typical "stainers" and 3 "non-stainers" was made based on the individual tendency to develop extrinsic discolorations of teeth after a ten days rinsing with 0.2% chlorhexidine twice a day. The individual discoloration tendency was maintained through various plaque-preventive regimens. Interference with the retention of chlorhexidine by a cation demonstrated a close correlation between antiplaque activity and the discoloration tendency. A commercial oxidizing agent based on peroxy monosulfate showed the most promising properties in reducing this extrinsic discoloration without interfering with plaque-prevention.