What a great question. I remember being a new graduate dentist 27 years ago, when a bomb shell hit me, fillings don’t last forever! This was such a shock to me, as I had assumed, even throughout dental school, that the treatments we provide are final.
Unfortunately, the reality is very different and the answer to the question is that longevity of dental fillings depends on many factors.
Let us think of the mouth as a car engine. There are moving parts. There is friction (chewing). There is thermal expansion (hot food/drink). There is contraction (cold food/drink). There are shear forces (grinding food). There are compression forces (biting food) and tensile (chewing food) forces. There is cyclical fatigue and there is chemical erosion (sweets, chocolate, fizzy drinks and citrus fruits). What a hostile environment!
Your car needs a regular service and parts need to be replaced and maintained. The more you drive your car, the more the wear and tear. If you drive in a harmful way to the car, it will break down sooner. The oral environment is no different.
Fillings undergo all of the above forces and therefore need careful monitoring for breakdown and failure. Just like the car analogy, a part could be failing, but you may not notice or feel it. There are no signs or symptoms, except that the mechanic is telling you so. Similarly, we dentists are trained to pick up and advise when fillings are starting to wear.
If your dental hygiene is poor or if you overwork your fillings, then their lifespan is compromised. Experienced dentists can advise as to how long they expect the filling to last once fatigue signs are noted.
I often hear of members of the public shopping around for the best price for their treatments. This is understandable given that the cost for dental treatments is often high and under-subsidised by governments and insurers. Politics aside, this is about health.
Would you believe that all fillings are not alike?
Your dentist chooses the filling materials for you. It may or may not come as a surprise, but there are hundreds of different filling materials dentists can provide. You may even remember the old amalgam or gold fillings of the past. All filling types have different properties and qualities. They are also manufactured in different countries. We can choose between high-end, branded materials, which tend to last longer. For the budget conscious dentist and patient, cheaper fillings may be used. Like cheaper tyres for your car, these fillings are not likely to last as long and need replacing sooner. They may leak and allow bacteria to ingress sooner.
Modern fillings are teeth coloured and made from a resin. Their installation requires a specific protocol and is very technique sensitive. The skill and experience of the dentist is another important factor in the longevity of the fillings provided. A highly skilled dentist can give you a filling that can last for decades.
In summary, dental fillings do not last forever. In order for you to get the longest lasting treatments, you should make sure you visit a reputable dentist who’s judgement and skill you trust.