This is a very common question, as there is often a choice.
So – first off – what is a crown? A crown, or ‘cap’, is a lab manufactured, super strong, cover for your entire tooth. The bottom of the crown has a seal that stops anything from getting inside and at your natural tooth. It is a sealed, protective shell, that protects your natural tooth, that will not wear down. Or –an impenetrable suit of armor! The only down-side, aside from cost, is that some of the surface of your natural tooth is roughed up, allowing for the seal and bond to be as strong as it can.
Fillings, on the other hand, are attached to the natural tooth, but do not protect any of the actual tooth – they replace parts of your tooth. Too many fillings on one tooth – or very large fillings – will actually weaken the tooth itself, making it more likely to crack or split. The less tooth, the less support and the less area with which to disperse the force of biting, putting more pressure on whatever percent of the tooth is left. Again – fillings do not contribute to your tooth’s support or strength -they take away from it.
So – we now get to should you get a crown or just fillings? In short, for the reasons I just talked about, a crown is always better. But – it is more expensive. So the question your dentist is likely asking, when making their recommendations, is how much more beneficial the crown will be, over fillings. If fewer and smaller fillings will work, or if the filling is larger but not in a structurally critical area, fillings may work very well. The are less expensive, and last 10 to 20 years on average. They will not damage your tooth if they fall out – eventually. But – if there are too many fillings, or a larger filling in a structurally important part of your tooth – the risk of having your tooth break with regular use climbs very very quickly. If that does happen – you will be in an even worse position than before, need more work, and have greater costs than if you went with the crown initially.
If a crown is recommended or needed, think of having fillings as a temporary solution, that may work for a while at best, and may result in more damage and a bigger bill in the future – or losing the tooth completely at worst.