Dr Susan Stewart talks to us about why our teeth can crack & break, and the life span of our fillings. 

1/ Why do teeth crack or break?

Tooth enamel is the hardest tissue in the human body, but it still suffers from stress fatigue.  Pressure on a tooth causes the tips of the tooth to bend outwards.  Having a hole in the middle of the tooth, whether decay or a filling, makes it bend more.  After many bites on the tooth, small cracks are created.  These cracks grow longer and wider and eventually give pain and/or the tooth breaks.

2/ How long should fillings last?

I’d love it if fillings lasted a lifetime.  Unfortunately they don’t.  We throw a lot at them, the biting forces, sweet and sticky foods, acids from the plaque bacteria, opening things (you know who you are!), and we get older and so they can deteriorate.  This leads to the potential for staining, food packing, filling fracture and/or decay so then the filling needs replacing.  Having said that, filling materials are relatively durable with the composites lasting between 7 to 10 years, and the modern crown materials and gold lasting up to 20 years.

3/ Should old amalgam fillings be replaced?

Yes, absolutely. I’ve been using composite (white filling materials) instead of amalgam for 20 years now.  That makes any of the amalgam fillings still around truly past their best by dates.

These days we tend to see a lot of amalgams that are causing fractures due to their wedging effect on the surrounding tooth walls.

4/ What are the options available to fix broken teeth?

There are the composites which have been developed to work as well if not better than the amalgams.  They are beautiful in small to medium cavities, but are not strong enough in big, wide areas.  If there is more than half the tooth missing the best solution is to have a crown fitted.  The tooth coloured ceramics that crowns are now made of are strong, have long-term durability and really lock the tooth together to prevent any more flexing of the tooth.

5/ Do broken teeth have any other effects on your general or oral health?

Pain is one effect of broken teeth that I see most of.  It could be simply cold sensitivity or the sharp edge of the broken tooth has cut the tongue.  Worse is the pain from the exposed nerve of the tooth. Without the enamel cover, bacteria are able to get into the pulp or nerve of the tooth.  From a health point of view, the pulp is supposed to be the barrier between you and stuff that needs to stay outside of your body.  It can’t do that job if it becomes infected; this is also when the tooth becomes painful.

The effect on your oral health; with bits of teeth missing, other teeth have to take more pressure and strain which causes them to be more liable to crack and break.  The whole bite can change which affects the jaw joints and the muscles around them.  There is also less height to the teeth and so the chin gets closer to the nose so it starts to look like there aren’t any teeth in the mouth, the “denture look”.

6/ What home care regime do you suggest and how often should we visit the dentist?

I am a big fan of flossing.  Floss once a day just before you brush. Either morning or night- just what ties in with your time really.  Flossing regularly helps to make your fillings last longer.   Brush with a soft toothbrush morning and night every day.  Spit out the excess toothpaste rather than swish it all out with water.

How often should you visit? Generally a check-up every 12 months keeps problems away. Some people need 6 monthly checks as things keep changing in their mouths.

 Definitely come along if you think something is wrong so that we can either put your minds at rest or fix a problem before it becomes a bigger problem.