A few weeks ago, one of my patient’s and I were discussing why a crown may not last forever and he mentioned this topic would make a good article, so here it is!  First off, let me briefly explain what a crown is.  Many people call them “caps”, but they are more appropriately termed crowns.  A crown is a restoration that covers a tooth to restore it to its normal shape and size while strengthening and improving the appearance of a tooth.  Crowns are necessary when a tooth is generally broken down and fillings won't solve the problem.  If a tooth is cracked, a crown holds the tooth together to seal the cracks so the damage doesn't progress.  Crowns are also used to support a large filling when there isn't enough of the tooth structure remaining, to attach a bridge, protect weak teeth from fracturing, restore fractured teeth, or cover badly shaped or discolored teeth.

I am often asked how long a crown will last.  Insurance companies will replace a crown every five years because that is how long they feel they should be in the mouth before it fails.  All of that said, if a crown is lasting only five years, something most likely has gone wrong.  I’ve seen crowns that have been in the mouth for over fifty years and are still functioning very well!  With good oral hygiene, regular oral hygiene visits and supervision, crowns can easily last for years and years, if not a lifetime.  There are very little things in today’s world that will routinely last ten, twenty and more years like a crown can.  Yes, I am biased, but what an incredible value you get when a precision fitted crown is placed in your mouth.

Even though crowns can last for years, there are circumstances that can limit their longevity.  Some damaging habits like grinding your teeth, chewing ice, or fingernail biting may cause this period of time to decrease significantly.  Another factor that comes in to play is the amount of tooth that remains as the supporting structure under a crown.  The more tooth framework that has been broken off or destroyed from decay, the less support you have for the crown.  This in turn increases the potential for failure.  Another thing many people don’t consider is how far down a crown has to be placed on a tooth.  If a person’s gums have receded and a crown has to be finished on a root surface rather than the stronger enamel, the life of crown can be decreased.  Roots decay much more readily than the enamel since it is a softer structure and more susceptible to the acidity of plaque.  It is important to remember that where the crown stops and the tooth starts, it is still tooth and it can decay.  This is another reason why gum health is so important to your overall oral health.

Another factor that affects the longevity of a crown is the material it’s fabricated from.  The crowns that have been in the mouth for over fifty years were all gold crowns.  As you can see, there is potentially a trade off between the life of a crown and esthetics.  The better porcelains of today that many crowns are made of are absolutely beautiful and can be indistinguishable from natural tooth structure if fabricated properly.  Porcelain crowns can last for years, but they are still glass and if placed in an area with excessive forces, they can more readily break.  The further back in the mouth you go, the stronger the biting forces that are present.  If there are areas in your mouth that teeth don’t show, cosmetics aren’t a concern and it doesn’t bother you, you may want to consider a gold crown for longevity.  Otherwise, make it look natural with a porcelain crown.     

To prevent damaging or fracturing your crowns, avoid chewing hard foods, ice or other hard objects.  I you’re someone who grinds your teeth, look in to having a bite splint fabricated by your dentist for night time wear.  Besides visiting your dentist and brushing twice a day, cleaning between your teeth is vital with crowns.  Floss or interdental cleaners (specially shaped brushes and sticks) are important tools to remove plaque from the crown area where the gum meets the tooth.  Remember, plaque in these areas can cause decay and gum disease which in turn means the failure of a crown.  I hope you have a blessed week.