The FAQ – Fillings for Decay section covers many questions about what a dentist must do to fix a tooth by doing a simple, direct filling on the tooth.
You may go to the answers below and there are links to other chapters.
Questions about Fillings for Decay
- Why do you need a filling if you get decay?
- What types of fillings are there?
- How big can the filling be without needing something more expensive to fix the problem?
- How long should a filling last before it needs to be replaced?
- Do most dentists do fillings that last the expected lifetime?
- Are there different materials that can be used for fillings?
- What is the best material to use for a filling?
- Are any materials used for fillings toxic, or present the possibility of a future health hazard?
- How many fillings per year are done in the U.S., and throughout the world?
Answers about Fillings and Decay:
- Why do you need a filling if you get decay? When you get decay some of the tooth structure has been softened by acid from bacteria. This softened tooth structure, enamel and/or dentin, must be removed, because that softer material contains more of the harmful bacteria. This softer area must be totally removed until hard tooth structure is again revealed, in the deeper areas, and all around the surface of the excavation in enamel. Then the void that is left must be filled with some material. If this filling is not done, then the “cavity” created in the tooth will fill with bacteria and the decay will start all over again…………………BACK to questions
- What types of fillings are there? Once this removal process is done, the area must be filled with an artificial (non-tooth) material – either silver amalgam, gold, porcelain or composite resin plastic. There are disadvantages and advantages to each material, which is why they are all still readily available in dental practices. ………………..BACK to questions
- How big can the filling be without needing something more expensive to fix the problem? The more expensive procedure suggested here would some kind of crown (visit Chapters V.6, V.7, and V.8) – that is a gold or ceramic piece that is made in the laboratory which is cemented into or over the void created by removal of the decay. That void and the remaining tooth structure needs to be altered in form so the cemented piece will fit well and stay in for a long time. It is far less expensive to restore the tooth directly, by just packing some material into the void. The two materials that are used for this are either silver amalgam or composite resin. Since the composite resin wears out far faster than the silver amalgam, it is rarely used for larger restorations. Silver amalgam, on the other hand, can be used to restore the entire bulk of the tooth in the mouth, obviating the need for a crown. It resists wear well over the years and also resists further decay around the edges………………… BACK to questions
- How long should a filling last before it needs to be replaced? The two materials which need to be compared in this respect are silver amalgam and composite resin. I can tell you how long each SHOULD last – the amalgam is virtually a lifetime restoration, where the composite should last 12 – 15 years. These are the lifetimes if they are done well, following the guidelines and methods taught in dental school. In REALITY, an amalgam would likely last 25 years, whereas most dentists will tell the patient, IF asked, that the composite will last 5-7 years. I always ask my students that are working as dental assistants how long the composite restorations last for the patients in the practice where they work – and the answers range from 3 to 9 years…………………BACK to questions
- Do most dentists do fillings that last the expected lifetime? NO! Unfortunately. Dentists can charge more for composite resin restorations because they take longer to do, but they often cut corners and do them more quickly to make more profit. Sad to say! Some dentists use the full technology we have available, and take their time with restorations, so the optimum result is achieved. But, many use abbreviated methods and materials which results in the shorter lifetimes. When a dentist does a silver amalgam filling these days they are typically the kind of person that will make the effort to see that the restoration serves the patient for a long time………………… BACK to questions
- Are there different materials that can be used for fillings? Yes there are. In fact, there are different choices even when it comes to composite resin fillings. There are different types of composite that are designed to be used in various particular circumstances. There are resins that can be polished more, for use on the visible anterior teeth. There are resins that resist wear more that are used in the back teeth. There are resins that shrink less when cured, and these are designed to be used to rebuild the deeper parts of the void or cavity created by removal of the decay, and then the dentist builds the final contours with the more wear-resistant material. There are composite resins that flow more, so they adapt better to deeper parts of the tooth, and are more flexible after curing so they work better on teeth that are bending in the mouth. For silver amalgam all material choices have pretty similar properties as far as the patient and longevity are concerned. There are other materials that may be used for certain classes of fillings, but these will be discussed in another section…………………BACK to questions
- What is the best material to use for a filling? For me, I always get amalgam. YES – I do still get decay from time to time. Not all dentists will actually DO a silver amalgam filling. I hope the dental community will forgive me if I indicate that the reason many dentists do not do silver amalgam fillings is they make far more money doing composite resin fillings. Most would claim that they feel it is healthier for the patient to use the composite – but that is not the position of the ADA and all peer reviewed literature in the field. Now – that being said, there are circumstances where a composite resin restoration is certainly to be preferred: in visible areas if appearance is an issue, and in areas where the adhesive properties of the composite materials would allow for a significantly smaller restoration (this is unusual, however). I have one composite resin restoration in my mouth, in a small tooth where an amalgam would have been tricky to do without compromising the remaining tooth structure. It will need to be replaced in a couple more years, but it’s been there for 15 (it was done by the best dentist I’ve ever known). Bottom line – there are choices. There may be a best for a given circumstance, but there is NO best in general!………………..BACK to questions
- Are any materials used for fillings toxic, or present the possibility of a future health hazard? The silver amalgam has always been questioned as far as health is concerned, because of the mercury content. However, the mercury is bound so tightly in the filling that there is little exposure of the body to mercury, far less than you typically get if you like to eat Swordfish or tuna. I will elaborate on the research in this area in another section. There has been some concern over the years about the plastic resin materials in composite restorations affecting the hormonal balance in females. I will refer to the latest reports on this in the other section as well. Bottom Line – there is virtually nothing to be concerned about as far as the safety of any filling material…………………BACK to questions
- How many filling per year are done in the U.S., and throughout the world? For the U.S. there are approximately 100 million fillings done every year, and about half of these are amalgam. This percentage is about the same worldwide, although there are European countries that have banned amalgam or made the compensation for the dentist so low they cannot afford to do them for their patients. Dental decay affects around 3.9 billion people on the planet. If everyone had just one filling, that would be a lot of fillings!……………….. BACK to questions