There is a selection of materials available for dental fillings, and the choice is often determined by the position and size of the cavity which needs to be filled. Obviously fillings which are in the back of the mouth are not nearly so visible, and it's possible to choose economical and hard wearing restorations here. However fillings which are in the front of the mouth must have good aesthetics in order to look natural.
Amalgam fillings have been used for many years and are still an excellent choice as they are extremely durable and strong and can withstand the heavy biting pressure of the back teeth. In addition they are a very cost effective and functional option, and are ideal for areas where it's difficult to keep the cavity preparation dry, which is essential for some types of filling. There have been a lot of scientific studies into the safety of amalgam as it does contain a tiny amount of mercury. All the major health and scientific organisations have concluded it is perfectly safe for long-term use. It would be extremely rare for a patient to have any kind of allergic reaction to amalgam.
Composite fillings are a good choice for small cavities that only have to withstand a moderate amount of biting pressure. They are made from a tooth colored material which is primarily resin-based and mixed with a glass or quartz filler. Composite fillings can blend in well with natural teeth and produce good aesthetic results.
Glass ionomer fillings
Glass ionomer fillings are ideal for using on the root surfaces of teeth as they are extremely translucent and require very little tooth structure to be removed. Although they produce a very pleasing aesthetic result they are not very strong and cannot be used in areas which are subjected to any kind of biting stress.
All fillings are designed to seal up the cavity so that bacteria cannot enter, and it's quite likely that they will need renewing periodically as they age, as they can become leaky if they become cracked or the edges start to crumble. Regular check-ups will allow us to see if any of your fillings do need renewing, and an early sign of this can be increased sensitivity to hot or cold foodstuffs as the dentin of the tooth becomes exposed.