Jeffrey Caso Post-operative sensitivity plagues us all from time to time. Fortunately, if we understand its causes we can take action to prevent the circumstances leading up to it. In addition, we can use materials developed to stop it cold.
The leading theory of what causes sensitivity in general is the Hydrodynamic Theory. It is simply that movement of fluid within the dentinal tubules deforms the nerve endings in the pulp and elicits pain. This is something we all have learned, and it makes sense. So what do we do about it? Simply, we need to seal the dentinal tubules to stop this movement of fluid.
Let’s start by listing the most common causes of dentinal sensitivity that we as practitioners have some control over. This list came directly from the Heraeus Kulzer website.
- Over-etching the dentin
- Dehydrating the dentin
- Inadequate marginal seal (commonly caused by contamination)
- Using expired adhesive
- Failure of dentin bonding (not following directions)
- Inadequate light cure
- Oil contamination from the dental unit
- Using cavity liners like Glass ionomer, which can microfracture after placement and separate from the dentin
I will add two more which I feel are important as well:
- Incomplete removal of Titanium Dioxide powder
- High occlusion
There is so much that can go wrong in dentistry, fortunately we have products designed to help us right our wrongs. Now, don’t misinterpret my remarks. Look at the above list and take every precaution that you can to avoid those errors, but just in case, I use Gluma by Heraeus Kulzer on every vital tooth that I restore. It is 5% gluteraldehyde, 35% HEMA (hydroxyethyl methacrylate) in water. Its main action is to reduce post-operative sensitivity, but it also is a cavity disinfectant and a re-wetting agent or adhesive promoter. Its mechanism to reduce sensitivity is by reducing the permeability of dentin by precipitating plasma proteins to seal dentinal tubules. A study on the Heraeus Kulzer site shows that it actually occludes the tubules up to 200 microns. That’s pretty effective in my opinion.
Well, that’s a great deal of information and a lot to think about in terms of our technique. It was a necessary precursor to understand one thing. As Gluma is compatible with virtually every bonding system out there, the big question is: When in the process do I place it?
Think of it this way: It needs to be placed on dentin that has not yet been affected by the bonding agent. So, if utilizing the total etch technique, apply after rinsing off the etchant. If you are not etching, place it at the start of your bonding process. That’s it! Very simple.
Here is my technique: Isolate perfectly, if using a total-etch technique apply and rinse etchant, apply Gluma, then follow your bonding protocol. If using a self-etch system, then apply Gluma right after isolation. Either way, I lightly dry the dentin, scrub in Gluma for one minute and dry, reapply for one minute and dry and then follow the rest of my bonding steps. I do not rinse the Gluma at all.
You can read more and see the study’s that support this at http://www.heraeus-dental-us.com/.
