Post Operative sensitivity can be both a normal and abnormal sequela of placing a posterior composite. I make sure my patients are expecting some temperature sensitivity, and even tell them to be cautious the first time the have a cold drink after the anesthetic wears off. Beyond the mild pulpitis that can be induced during the preparation and placement of a posterior composite is the sensitivity that lingers. When I speak with dentists who have a question about sensitivity, the first thing I ask them to do is recount heir adhesive technique with me. The reason is that almost all lingering issues can be tagged on a piece of the adhesive process.
Number one on the list for causing sensitivity is over etching the dentin when using a total etch technique. Dentin should be exposed to phosphoric acid for no longer than 15 seconds, and recently I have been hearing ten seconds. Second on the list with a total etch technique is over drying the dentin after rinsing the etch. This is a tricky step, but we need to remove the pooled water, but leave the dentin moist enough that the tubules do not collapse and the primer can be carried into the tubules as it chases the water. The last issue with self etching products is ineffective use of the primer. Make sure you know the instructions regarding length of time to agitate and number of coats. With self etching products one of the classic issues is inadequate etching during the first step. The etch/primer requires a time interval of scrubbing it against the dentin to activate the etching component.
Beyond the dentin adhesive, I look at the placement technique for the increments of composite and the shrinkage stress of the material. Placing too large an increment and using a material with higher shrinkage stress can cause failure of the hybrid zone and post op sensitivity. So if you are experiencing more sensitivity than you would like go back and step by step review your technique.
I agree with everything you say Lee. Have you had any experience with Sonicfil or any of the other “bulk” fill materials? The reps want me to sample them and they state you can do 5mm bulk cure without issue. I find it hard to believe especially with the “C” factor. I welcome your opinion on the subject.
Hans,
I have used a number of the new bulk fill composites. With these materials as well as our newer more traditional composites the issue isn’t polymerization shrinkage, but it is shrinkage stress. These materials have relatively low shrinkage stress even with a larger increment.
Lee
Hi Lee, Enjoy your articles. I have been using a technique for years and can’t remember the last time I had pot-op sensitivity (especially that “rebound” biting sensitivity). I etch the enamel for 5- 10 seconds (if a little gets on the dentin, it is only on for a short time), I dry but don’t desiccate, re-wet with Glutaraldehyde/HEMA (Microprime-G), blast with air, then use a self-etching primer/bonding agent (Brush&Bond). If it doesn’t look shiny, then I apply a second coat. Finally I apply a very thin layer of flowable to wet the dentin and make sure there isn’t any voids. (I know, this step may not be necessary, but since I’ve had such great results I am slow to abandon it. I also build up opposing walls separately. God bless!
Hi, Lee, Have you ever considered Surpass bonding system? It is made by Dr. John Kanca, Apex Dental Materials. What I particularly like is that step one is left sopping wet, step 2 dessicated dry and step 3 it doesnt matter if it is thinned or not. No guessing, did I over etch or over dry. I NEVER have patients with even temporary sensitivity. NEVER!
I love your blog, by the way. You are inspirational to me. Thanks for your contribution to our profession.
Rix
Frederick,
I have not used it, but do hear great things about it from dentists who do. Keep doing what you are doing if it works!
Sensitivity has been an issue with most dentists that I have spoken with over the years and it appears that the need for speed has a lot to do with it no matter what products are used. Etching too long may be an issue but I think that drying too much (collapsing collagen), placing adhesive and then air-drying right away results in No Hybrid Layer hence sensitivity. Dispensing adhesive too soon before using changes the chemistry and therefore the bond depending on the type of carrier used(acetone, ethanol, water) as it evaporates. Obviously trying to cure layers of composite which are too thick adds to the overall problem. I say spend the time up front with a great technique, standardize it every time and then you won’t have to try and explain why the patient has a sensitive tooth or worse redo the restoration (at least almost never, I don’t ever believe in nevers in dentistry).
What about using a small layer of RCGMI limited to dentin only??
The challenge with RMGI is bond strength. It bonds to dentin at about 7-10 MPa, and then we have composite over that, so if we cover all of the dentin we do not have hybrid zone development and are dependent on enamel bonding at the margins. I use it locally over areas of deep decay, although more recently I use a product named TheraCal from Bisco.