The problem we have is, teeth that have dodgy nerves are not always symptomatic or painful, and the tooth may be partially dead and yet still give a 'normal' healthy response to testing.
We presently have no way of measuring the degree of health of a nerve. We can only determine whether the nerve is dead (non-vital) or alive (vital). In the case of a tooth that needs a crown, if the tooth tests as 'non vital' or having a 'dead nerve' it would be necessary to undertake the root canal procedure first before placing the crown.
In cases where the nerve tests 'vital' the crown can be placed, but there is no way of really knowing the real degree of health of the nerve and even though the tooth tested vital, the nerve may be partially dead and the mere act of preparing the tooth for a crown may accelerate the inevitable need for a root canal procedure. In this case symptoms may only present weeks or months later, in which case a hole will need to be drilled through the top of the new crown to gain access to the root canals of the tooth, possibly affecting the integrity of the crown.
Nerve symptoms are highly variable, but include:
- lingering pain to cold,
- pain to hot (can linger as well),
- relief of pain by placing cold liquid against the tooth,
- a spontaneous pain that seems to move around but never crosses the midline
- a throbbing pain that wakes you at night
- acute pain on biting