It is very common for new tooth-colored fillings, and temporary crowns, to be “high” after the numbness wears off. Usually, this is accompanied by “sensitivity” to cold foods or drink that disappears as soon as the tooth warms up to body temperature again. The same problem can also occur when new crowns are placed, depending on when the dentist records the way the teeth come together. Although a small percentage of this may be attributed to the physical properties of the filling material during their setting from a paste to a solid, most of these post-operative problems can be attributed to the way the muscles of the jaw respond to the mouth being open for extended periods of time.
The jaw is a complex appendage, held in place solely by muscles and ligaments. Between the jaw and the base of the skull, just in front of the ear, is a cartilaginous disc that is shaped sort of like a doughnut. A relatively small muscle, called the lateral pterygoid muscle, attaches to that disc and the jaw bone and pulls the disc forward and downward when the mouth opens. If overworked, this muscle can go into spasm, much like a Charlie-horse occurs in the calf muscles. Sometimes a spasming lateral pterygoid muscle can cause pain, but usually after a lengthy dental appointment it keeps the disc slightly forward of its relaxed position. This “opens” the bite on the back teeth slightly until the muscle completely relaxes, which may be hours or days after the appointment.
Since all of the contouring and adjusting of fillings and the making of temporary crowns occurs after the mouth has been opened for a time, it is often unavoidable for a dentist to leave them inadvertently “high”. Some dentists choose to record the way that teeth come together at the end of a crown appointment before making a temporary crown. This technique may inadvertently cause the permanent crown to be made “too high”. Regardless of how it occurs, most “high bite” cases can be attributed to a fatigued and spasming lateral pterygoid muscle.
The good news is that usually only a minor adjustment is needed to get the tooth comfortable again. However, larger pre-existing problems can become evident after even “simple” dental procedures that may otherwise have gone unnoticed until much more painful or uncomfortable symptoms arose. As examples, the tooth may be dying and beginning to abscess or the early stages of TMJ problems and headaches are beginning to appear. Older-style amalgam fillings tended to “wear in” for the first 24 hours after placement because they were not completely hardened immediately after placement; however, the new tooth-colored composite resins are just about as hard as they will get when the appointment is over. They will not “wear in”. This is why it is so very important to contact your dentist whenever a tooth is not comfortable after a dental appointment.