What causes sensitivity in crowned teeth?

Traditionally dentists have believed that this sensitivity stemmed from cracks in the teeth, previously injured pulps, and dying pulps. Some 'traditional cements' have been known to occasionally cause a pulpitis when they were used for cementation ( Zinc phosphate and glass inomer cements). This type of cement induced sensitivity occurs immediately after a crown has been cemented and the symptoms are predominately sensitivity to cold liquids. This sensitivity often goes away with time. In my experience it can take up to a year to resolve, but occasionally a tooth may require a root canal in order to resolve the problem of this cement induced sensitivity.


Recently new resin based cements have become popular with many dentists and they may be to be causing a whole new category of sensitivity. Although they can cause traditional type of cement sensitivity, most times they do not. They have the advantage of actually 'bonding' to the tooth. Supposedly, this is an advantage, but the problem in my mind is that under chewing pressure and function this bond may fail. If that happens, the crowns often do stay in place, but probably become leaky. This leakage can cause sensitivity and can cause sensitivity to biting as well, since under pressure the crowns may flex very slightly against the tooth.

I do use some of the newer resin based cements and I have experienced some patients who have complained of this newer form of 'delayed sensitivity'. Recently I tried an experiment. I had a patient who was complaining of sensitivity every time she drank cold. Her crown was cemented with a resin based glass ionomer cement and seemed well fitted and well cemented.

I removed the crown and fabricated a traditional acrylic temporary cemented with a eugonal based temporary cement and her symptoms immediately disappeared. Although this a sample size of only one, I wonder how many other patients are experiencing the same problem?