An in vivo comparison of chlorhexidine and picloxydine mouthrinses: a possible association between chemical structure and antiplaque activity.

A double blind clinical trial was conducted in which both the plaque-inhibiting ability and the in vivo effects on the oral flora of chlorhexidine and picloxydine mouthwashes was compared. While picloxydine in higher concentration suppressed the oral flora more effectively than chlorhexidine, the latter agent inhibited plaque development to a much greater extent. This lack of correlation between antibacterial and antiplaque activity can be related to structural differences between these two bis-biguanides.