Sometimes, despite your best efforts at oral hygiene you may still have some areas of “tooth decay”. You may wonder what decay actually is and why we get decay. Believe it or not, there is an entire field of research devoted to tooth decay termed Cariology. Tooth decay is actually termed dental caries. The term cavity relates to the result of having bacteria present which decay the teeth causing an actual “cavity” or hole in the tooth structure.
How does a cavity occur?
In order for caries to be present, there are four prerequisites. First there must be tooth material present. There must be a substrate (sugars), there must be micro-organisms present, and time. Without these four factors then dental caries will not occur. However, unfortunately for us…as long as we have teeth, we have the potential for decay.
Dental caries can occur in all of the three layers of the tooth and eventually invade the pulp. Common areas of decay include the grooves and fissures of the occlusal (biting) surface of teeth, in between teeth just below the point of contact, and along the buccal (cheek side) surface of the teeth along the gum line. Early enamel decay may appear as a small white spot. These white spots may eventually change in color due to the absorption of stains from the diet or due to byproducts of the bacteria. Believe it or not, the caries process does not actually start on the surface of the tooth. In fact the process is initiated below the surface by a subsurface lesion where there is a loss of mineral under the surface, however the surface is intact. The early decay process is initiated by hydrogen ions which pass through the tooth structure and act to dissolve calcium and phosphate which partly makes up the enamel. This is important because until the clinical surface of the lesion is damaged, it is still sterile and can re-mineralize. Remineralization can be promoted by fluoride, removal of plaque (good oral hygiene), proper diet (a reduction in the frequency of sugar consumption), and by stimulating salivary flow (chewing sugar free gum, or sucking on sugar free candies). Once this clinical surface breaks down, then bacteria will invade the cavity and a filling will ultimately be required.
When the cavity reaches the dentin layer, the decay advances rapidly. This is because the dentin is composed of tubules and is more permeable than enamel. Our bodies will make an effort to respond to the decay once it reaches the dentin layer. As cells which line the pulp (odontoblasts) are able to sense decay once it reaches the dentin and will begin laying down extra mineral deposits to try and “block” the caries. This functions in moving the pulp further away from the caries. However, once the surface of the enamel breaks down, plaque and bacteria invade the cavity and will also hasten the decay process. The invading bacteria often contain proteolytic enzymes, which act to further destroy dentin. At this point the patient will begin to feel sensitivity to heat, cold, acid and pressure. Eventually the bacteria will work through the dentin into the pulp and cause a condition which is termed pulpitis (inflammation of the pulp). Therefore the old saying that it is too late once it hurts is true!
What are the different options for my filling?
There are many different restorative options for restoring teeth which can include:
Amalgam (silver) restorations
Composite (tooth colored) restorations
The decision of which restorative material to use is dependant on many factors such as the location, and extent of decay, and patient preferences. The final decision should be made after consultation with the dentist.
**Please discuss with your dentist the option that is best suited for your case.
Is there anything that I can do to reduce my chances of getting tooth decay?
Yes there is! Once of the best ways of reducing your chances of developing decay is to have good oral hygiene habits such as brushing two times a day, once in the morning, and once in the evening before bed. Flossing is also essential to do at least once a day.