Reduction coping

plastic reduction coping

Reduction coping

Reduction coping is useful for us dentists if we need more room for a dental crown after we already prepped and impressed the tooth. This most often occurs on second molars as it is difficult to properly evaluate the clearance of a second molar. To me personally it also happens more often on teeth that need a build up. That is because I can prep 2mm away occlusally pretty consistently, however adding material back and keeping at the same clearance is tougher.

Reduction coping dental lab steps

The steps involved in making a reduction coping will vary from lab to lab. I have seen my dental lab technician use different forms of plastic and acrylic. I don’t have a preference for any of the different types that I have seen. Therefore to any lab reading this my opinion is use whatever is quickest, easiest, and cheapest for you.

Step one is to determine that a reduction coping will make the preparation more ideal. The second step is informing the doctor that the patient should have one. This is the tricky step because it involves open and honest communication. Also depending on the doctor preference, the occlusion, the height of the remaining tooth structure that is prepared, and whether or not the tooth has already had a root canal we may want to reduce the opposing instead of making a reduction coping. It is always best to snap a couple photos and send an email asking the doctor whether they prefer reduction coping or to adjust opposing.

Once we determine a reduction coping is going to be done the actual work begins. Step 3 is reduce the model to make ideal. My lab marks the are that they reduce in black. Step 4 is get the plastic or acrylic around the tooth preparation and level with the adjustment. Step 3 and 4 may be in different order if that is your liking.

reduction coping dental lab
Photo showing area that we reduce in black and the coping.


plastic reduction coping
Model work and reduction coping shown separate.


Dental steps for a reduction coping

Not all dentists get their patients numb for a crown seat and this might make them not want to do a reduction coping. If doing a coping on a tooth that does not have a root canal, anesthetic is likely a necessity. Therefore Step 1 is get the patient numb.

Step 2 is place the coping on the tooth preparation. Step 3 is reduce the tooth prep.

reduction coping
Very minor reduction on a premolar.


Step 4 is seat the crown.

reduction coping dental crown
Final result with an emax dental crown