When I mention the word eruption the first thought is probably of a volcano or perhaps a geyser.  The process by which teeth enter the mouth is also called eruption.  Obviously it is a much slower process taking from several months to up to a year between the time it cuts thru the gum and assumes its normal position in the mouth.

Teeth are not “locked” into bone but connected by a ligament and stop moving when they have a force on them such as their counterpart in the opposing arch.  Under normal circumstances teeth never lose their ability to move or erupt.  It is the forces on them that dictate where the will move or stay.  This is the principle behind orthodontics and is also one of the reasons your dentist wants you to replace a missing tooth in a timely fashion.

This is an interesting case that came thru my door recently.  This first image is a patient that came in back in 2011 with a bad toothache in a lower second premolar.

His choice was either to do a root canal, followed by a post and crown, or have the tooth extracted. He elected to save the tooth. This is what the final result looked like.

As root canals go this is a pretty good one.  Notice how the fill goes all the way to the tip (we call it the apex) of the tooth.  Taking advantage of the fact that teeth are hollow, I created a large post space above it.  This is where the post will be placed that will hold the crown when the tooth is fully restored.

Unfortunately life got in the way and he never returned to have the tooth restored.  That is until last month. He came in with another toothache in the tooth behind it.  This time it was an unrestorable situation and while we were discussing the situation he asked me if I thought the premolar was still restorable so I took this radiograph to find out.

Because there was no force on the tooth over the three-year time period the tooth continued to erupt and as it was unprotected and exposed to the oral environment, it promptly decayed.  Since the tooth was without a nerve now, it never hurt.  Now after three years what was a restorable situation had become another tooth in need of extraction.  It would have been wiser to have had the tooth extracted in 2011 rather than go thru the expense of a root canal and an extraction.  In addition it now has become a harder, and costlier case to restore.  Pain serves a purpose in the human body.  It is there to alert you that something needs attention immediately.  There is often more than one way to solve the problem. If your dentist recommends treatment always ask for all the options and be aware that sometimes there is a time frame in which teeth can become unrestorable.