Many times, teeth can be so broken down due to extreme decay or fracture that there is not enough tooth structure available to hold a filling in place. In most of these cases, a crown (cap) would be indicated. However, certain situations may call for a change in plans. Things like inability to afford a crown, an unstable gum situation, waiting to see if a recent root canal will work, or any situation where the long term progression (outlook) is questionable are all possible reasons to go with just a filling. When there is not enough tooth structure to hold a filling, then pin retention is indicated. Pins are tiny threaded screws that are placed about ½ millimeter into dentin. A pilot hole ever so slightly smaller than the pin is drilled into the tooth, then the pin is screwed into place. An amalgam (metal) or composite (tooth-colored) filling is then placed over the top. The pin is only used for retaining the filling on the tooth. It does not reinforce like a rebar does with concrete. Pins have been known to cause microcracks in the dentin, however, I have not seen a fracture of the underlying tooth structure that was severe enough to lose the tooth that was caused by the pin alone.
Once root canal treatment has been performed then the tooth must be restored. Root canals are usually performed on teeth that are quite broken down and therefore must be built up to have enough tooth structure available to hold onto a crown. In order to retain the core buildup, many times a post must be placed inside the root canal. This is done by removing a portion of the root canal filling material (the part closest to the tip of the root is left to seal the end) and drilling out the proper size to accept the post (no need to worry about the drilling – remember there is no nerve in a root canal tooth). Then, the dentist chooses one of two types – a cast post and core or a prefabricated post. The cast post and core has advantages in that the core buildup is made as one piece with the post so there is no way for the two to separate. A disadvantage is that it must be fabricated outside of the mouth and therefore cannot be cemented on the same day, however, other provisions must be made to build up the tooth. Some prefabricated posts are metal and some of the newer ones are made of carbon fiber composite. The newer carbon fiber ones have a little bit of give to them and they look promising on possibly reducing root fractures in teeth with posts.
Periodontitis is a disease of the gums and causes a majority of the tooth loss in adults. The sad part is that over 90% of the cases are preventable. Periodontitis is caused by an interaction of bacteria which reside on the teeth and the body’s immune system. The bacteria adhere to the teeth by a sticky substance called dental plaque. The plaque protects the bacteria from antibodies in saliva, thus allowing the disease to progress. Simply by removing the dental plaque everyday would stop the disease dead in its tracks. Mild periodontitis is the first step past gingivitis, a reddening of the gums. It is marked by easily bleeding gums, especially when brushing the teeth. If good oral hygiene measures are initiated, many times the disease process can be reversed. Moderate periodontitis is accompanied by some bone loss. If caught at this time a procedure called scaling and root planing can be helpful in stopping the disease progression. From this point on, any bone damage is irreversible, so it is best to catch things as early as possible. Severe periodontitis is the point where the teeth will loosen and tooth loss can occur. These cases usually require surgery to give the sufferer access to all of the affected areas for the purposes of oral hygiene. Due to the irreversibility of the bone loss, it is always best to put the disease in check by daily home care and frequent professional checkups.