There are a few things to consider about fixing or restoring teeth.
First ask, why does the tooth need fixing in the first place? The two most likely reasons are that there is a relatively small hole in the tooth due to decay or there has been a breakdown of prior filling, cracking of tooth or something larger than the “small hole”.
If the hole is small the most likely treatment is for the Dentist to remove decay completely and fill the hole with either a tooth colored composite resin or silver (amalgam) filling material.
Composite resins are bonded to the tooth structure and will seal around the edges nicely. Placing these fillings is technique sensitive. If not done properly, chewing can be painful. Usually this will subside some weeks later.
Amalgam filling material is basically silver and mercury with various other metals used in trace amounts to add desired properties to the material. These fillings look dark gray unless they are polished to shiny silver, which is seldom done. Besides their appearance they’ve taken a bad rap because of the mercury. There are numerous studies which show that the mercury is not a problem. Litterally billions of these fillings have been done and may remain in service some 5 decades later. Regardless, there are those who persist in their thoughts. It’s almost a non-issue, however, because composite resin fillings have all but taken over as the material of choice.
For larger problems, the recommend treatment is often a crown or an onlay. The names only describe the amount of tooth covered. The crown usually extends more to the gum line than does an onlay. Both completely cover the biting surface and have the advantage of sheilding from biting forces that would tend to fracture a weak tooth. Think of a ferrule on a wooden chair leg.
Probably the best material for this treatment is a gold alloy. It’s kind to the opposing dentition and it’s slight malleable property produces an excelent fit. It’s popularity is waining because of aesthetics. It is gold color obviously doesn’t look like a natural tooth.
For many years the crown of choice was the “PFM” or porcelain fused to metal crown (technically it’s not fused, but bonded, so some may refer to it as a “PBM”). It’s made of a thimble like structure of gold (called a coping) onto which tooth colored porcelain is baked. They can truely fool the eye and look like a natural tooth if done well. One negative feature, however, is that the edge of the crown (called the margin) has to be placed just under the gum so that it doesn’t show. If that edge is visable it usually doesn’t look like a natural tooth. Therefore these crowns often have unnecessary tooth structure taken away to hide the margin.
The developement of all ceramic crowns and onlays has gone through a 20 plus year evolution to the point where they now offer a very strong and aesthetic restoration. There can be a tendency to fracture under heavy biting forces and may not be the material of choice for the very back teeth where forces are greatest. With careful attention to detail they can produce an aesthetic result that will look like a natural tooth without the need to hide the margin under the gum. This means the Dentist need only remove the tooth structure necessary to get the desired functional result.