Caries (tooth decay)
Conservative dental medicine is mainly concerned with the study of caries, that is how caries come about, how they can be avoided and how they can be treated. Most people believe that they have bad teeth. It is interesting to note that everyone always seems to have so called bad teeth only in the side areas. If truly bad teeth existed they would all be bad, even those in the front of the lower jaw. The origin of caries is plaque (dental plaque). Plaque develops after around 24 hours out of food and saliva components and out of bacteria and it triggers the formation of caries and/or periodontitis. Bacterial products (acids) within plaque lead to decalcification of the dental enamel.
In the early stages of caries you don’t feel any pain, since the enamel doesn’t have any nerves in it. It is when the caries affect the dentine (dental dentine), that some people feel an occasional twinge. When the caries reach the dental nerve then most people either feel a piercing
- oder einen throbbing pain
Caries starts off as small white flecks, known as white spots. At this stage no drilling is needed, as the demineralized enamel can remineralize again if the plaque is properly removed and kept away from the surface of the teeth. Sometimes caries has penetrated a little into the dentine and died due to a change in cleaning technique – you can see a black fleck in the dentine. This is dead plaque, as soon as the bacteria stop receiving nutrients and as long as the dentine isn’t too badly affected, the bacteria simply die in the caries lesion. In order for caries to exist it needs
- und time
Many of today’s dental fillings may remain fast for decades. Why do fillings become loose even when one takes good care of one’s teeth? Like everything else, even these materials succumb to the “bite of time” and after years, or perhaps decades, tiny gaps appear at the edge of the filling and a new outbreak of caries is the result – unless the filling is changed at the right time. Unfortunately the patient usually comes in not when the filling no longer seals completely, which doesn’t usually cause any pain, but rather when he has a toothache or when a piece of tooth or of filling breaks off. Often by then a root treatment will be required and the dentition deteriorates noticably. Regular visits to the dentist are needed to prevent things reaching so far.
What then is the best filling? This depends on many different factors but let’s start by dividing the various materials. These sub-divisions serve to explain better and have been freely chosen by me. We divide fillings into two major groups, those of plastic and those of non plastic materials. By plastic materials we understand all materials that the dentist prepares directly at the dentist’s chair. Amalgams, composites, compomers, cements, glasionomercements and various materials for temporary fillings belong to this group. With non-plastic materials we need to take a dental impression and a dental technician prepares fillings out of a particular material (such as ceramic, gold or titanium, for example) on the basis of this impression. What are the advantages and disadvantages of the particular materials?
Let’s start with plastic materials. The first advantage of all plastic materials as opposed to non-plastic materials is the lower price. If you don’t have much money available a well-inserted amalgam filling can give many years of good service. Even if you are in your eighties you would tend towards amalgam fillings, as long as there is enough original tooth material – and the savings made can be better used for a holiday with the grandchildren. If only very little tooth remains and/or if the tooth surfaces are already very thin and there is danger of fracture then a ceramic inlay could also be useful, despite the patient’s advanced age. A further advantage of plastic materials is the immediate treatment of the tooth. It’s true that amalgam fillings should be polished on the next day but the problem with the tooth is treated on the same day. Let’s move to plastic materials in detail.
No other material is discussed as controversially as amalgam. Fact is that exposure to mercury, e.g. through marine pollution is continually on the increase but this doesn’t affect people’s longevity, which is continually increasing too. Fact is also that the greatest exposure to mercury happens when inserting and drilling out fillings but nonetheless today’s dentists and their employees do not suffer from mercury poisoning. Fact is also that even in large studies it could not be proved that amalgam is dangerous. Fact is also that, amongst plastic materials, amalgam lasts longest. Fact is also, however, that a marginal amount of mercury is realeased and in addition these fillings aren’t exactly good-looking. These are all facts which neither the opponents nor the proponents can refute.
Before we go into the objective question of when an amalgam filling makes sense, let’s go a little deeper and think about why there are two such extreme viewpoints on this theme. Many people do not feel well nowadays. Symptoms like fatigue, tiredness, irritable bowel syndrome, dizziness, lassitude and chronic pain have become common. These symptoms are characteristic of our time and are a manifestation of the loss of societal warmth and empathy but they rarely have an organic origin. Organic in the sense of a medical diagnosis and treatment deriving from this. Unfortunately such people are just what today’s medicine is looking for (Medicalization).
The above mentioned symptoms are sometimes cured thanks to the attention of the practitioner – the placebo effect – and this leads to the patient believing in the effectiveness of the treatment. Opinions are thus created which are often very hard to change. In addition to all of this, people’s lack of knowledge also comes into it and most of us forget, when surfing the net, that what we are reading represents only the negative side, since a basic rule can be observed on the internet: the satisfied do not post! One doesn’t read about all the billions of people who have amalgam fillings but only about those who have a problem, whatever kind of problem that may be.
If you are young and have the money for non-plastic materials we recommend a non-plastic material such as a ceramic inlay. If you change your cleaning technique and your dentist does a good job an inlay like this will serve you for decades. The aim is to drill as little as possible in the tooth. Why? Every time we drill the danger of damaging the dental nerve increases and thus the need of a root treatment. If you are a student, for example, however, and you don’t have much money, and the fillings aren’t too big and they’re at the side, then an amalgam filling is definitely the best choice. When filling with amalgam, a metal loop is put around the tooth and little wooden wedges are placed between the teeth. The effect of the wedges is to ensure the loop fits very tightly around the tooth and later to permit a contact point for the filling with the neighbouring teeth. The soft amalgam alloy is pressed into the cavity in the tooth with special instruments and as soon as the filling begins to harden the dentists starts to carve it into shape. Every amalgam filling should be polished next day in order to make it smooth and thus limit the development of plaque.
Composites are frequently offered as an alternative to amalgam fillings but they aren’t a real alternative. Up to now, no composite filling has been approved by the manufacturer for use in the side teeth, where the chewing pressures occur. The emphasis here is on ‘chewing’. As soon as a composite filling is subjected to high chewing pressure it releases substances which damage the dental nerve and a root treatment is the usual result. This is hardly noticable. Some patients, days, weeks or months after the composite filling, complain of pain due to cold, warmth or pressure. This is usually a sign that the dental nerve is dying or has already died. Many patients allow themselves to be deceived by the white colour, i.e., the ‘natural’ look and even pay extra to get a white filling. Composites are a good filling material in areas where there is no chewing and when the filling isn’t too deep.
The disadvantage of composites when compared to amalgam is that they are far more prone to mistakes in preparation. A coffer dam should always be used when composites are being put in, as this is the only way to ensure absolute dryness. Another important criterion when filling with composites is the adhesion to the tooth – what we call bonding.
There is a wide variety of cements used in the filling of teeth. Since most cement fillings soon get washed out these are mainly used only for temporary fillings. Depending on the type of cement they last for between a few days up to a few months. Most cement fillings are white or grey and are usually very well tolerated by the teeth.
Compomers are a mixture of composites and glasionomer-cements. They combine the advantages of both, namely the good tolerance and the adhesion of cements and the longer durability of composites. Glasionomer-cements can remain fast for up to 5 years and in addition they release fluorides, which reduces the formation of caries. The material characteristics of compomers are superior to those of glasionomer-cements but they do not reach the material characteristics of composite materials. Since compomers are white, they are easy to confuse with composites. Experts can tell these fillings apart from the greater roughness. Compomers, like glasionomer-cements, make good materials for milk-tooth fillings due to their characteristics. The tooth surface must be specially treated in advance, as with composites.
Glasionomer-cements are distinguished by their good adhesion to the tooth surface. Another advantage is that they can be handled in a damp environment, as they were originally developed for use in dental treatment in Third World countries. There are also glasionomer-cements on the market which have been modified with plastics and these are activated usually by means of halogen light. Glasionomer-cements are frequently used to cement crowns or as a filling material for children, since the release of fluoride is greater than that of compomers. These fillings can last for up to 5 years, depending on the size of the filling, the load on the tooth and the execution of the filling. Both of the last two filling materials mentioned, glasionomer-cement and compomers, can be used as a temporary solution for adults until the changeover to non-plastic materials is possible/advisable but they are not really suitable as a long term solution.
Non Plastic Materials
These fillings are subdivided according to the material into gold inlays, ceramic inlay, or titanium inlays. According to size we speak about inlays, onlays or overlays. Some dentists charge a price which is not dependent on size; others on the other hand charge according to size and/or filling material. All these materials, when done properly and when taken good care of can remain fast for decades. It is important to ask the dentist with which material he works most and therefore with which he is most familiar.
Gold inlays depend a lot on the type of preparation, ceramic inlays in turn on the adhesive technique. If a dentist has been doing gold inlays all his life and you would like to have one of these, they you will be in good hands. It is best therefore to discuss things openly with your practitioner in order to establish your ideal filling.
We often read about allergies to dental materials in the internet. However, it’s usually not about allergies but rather about a normal reaction from the gums, for example due to loose and/or too large fillings. Loose or large fillings can lead to food particles collecting where they can’t be removed. This leads to bacterial infection with consequential bleeding of the gums and swelling.
If a dental nerve is damaged this has nothing to do with allergies but rather with some other cause which was there: large damage to dentine due to large fillings, too much drilling, too little cooling, opening of the dental nerve when inserting a filling or combinations of these. If the root treatment isn’t done properly then inflammations of the root-tip may occur after weeks, months or even years.
In order to have an allergic reaction there has to be an immune system but dental fillings rarely come into contact with immune systems. Classic allergies are marked by systemic reactions. A person allergic to bee stings, when stung on the big toe, will have a reaction all over the body, such as circulation or breathing problems and so on. Contact allergies which are principally limited to the surrounding area are much rarer, such as for example the skin rash caused by nickel-plated jewellery to those allergic to nickel. Contact allergies in the mouth are characterised by burning in the mouth and diffused swollen gums. Unfortunately some plastic fillings can cause similar symptoms which can be traced to a toxic rather than an allergic reaction.
The best filling is no filling
The coating on our teeth must be removed every 24 hours. This is usually achieved by brushing one’s teeth twice daily, flossing, and/or using a water pik.