For years I have always scrubbed my preparations with chlorhexidine.  There are a number of benefits to cleaning your preparations with chlorhexidine for both direct and indirect.  Here are some of the benefits:

1.     There are studies that show that using chlorhexidine as a re-wetting agent helps maintain bond strengths of your bonding agents.  

2.     If you are using the Bluecam or Redcam it gets any residual powder off the prep before you bond. 

3.     Cleans any tenacious debris that might not come off with regular rinsing.

4.     If you have used any astringent agent with ferric sulfate, it will prevent the black film from forming under your temporaries or final restoration.

5.     Disinfects the surface which may be part of the reason for #4.  Does this make a difference for bond strength or longevity- no but it makes me feel better. It certainly doesn’t hurt.

There are a couple of ways to use the chlorhexidine.  Some will saturate a cotton pellet and either scrub the tooth or leave the saturated pellet on the tooth while the crown is getting milled and fired.

I use a infuser tip on a syringe from Ultradent and fill the syringe with Consepsis which contains chlorhexidine.  Right before I start my bonding procedure I scrub the preparation with the chlorhexidine and leave it there for 30 seconds to a minute.  This is done while my assistant is dispensing the bonding agents out and/or etching my restoration.  I then just air dry it off. I don’t rinse with water.   I then bond per my usual protocol.