The excruciating pain of a toothache at 2:00am in the morning and the sleepless night that follows combine to form a situation no one would like to find themselves in. While there are other causes of toothache, the most common cause, by far, is tooth decay or dental caries. Dental caries is responsible for the majority of tooth losses (extractions) and to some extent, bad breath.
Your tooth is basically made up of an outer mineral layer known as the enamel, protecting the inner layer called dentine. The dentine covers an inner chamber called the pulp which contains the nerves and blood vessels responsible for the life (vitality) and sensation of the tooth. The human adult dentition has 32 teeth with incisors, canines, premolars and the back teeth, the molars. All teeth are anchored into the jaw bone by the supporting tissues called periodontal (periodontal-meaning around the tooth) tissues.
The severity of the symptoms associated with tooth decay is usually a direct reflection of the level of progression of the caries.
Dental caries also known as tooth decay is an infection usually bacterial in origin that proceeds with demineralization of the hard outer tissue of the tooth (the enamel) and destruction of the inner organic matter resulting into tooth breakdown which we typically see as a cavity on the tooth. The bacteria in a person’s mouth convert the sugars taken with food (usually glucose, fructose and most commonly sucrose) into acids such as lactic acid through a process called fermentation. It is this acid that is responsible for the above mentioned demineralization. If the rate of demineralization by the acidic products of bacterial fermentation exceeds the rate of re-mineralization by saliva, cavities then develop on the teeth.
There are four main factors responsible for tooth decay namely; a tooth surface (enamel or dentin), caries causing bacteria, fermentable carbohydrates like sucrose and finally the element of time. Host defenses like salivary flow and its inherent acid buffer capacity are perhaps the reason some people might be more susceptible to caries attack than others; but this is in consideration of other local factors like differences in sugar content in individual diets, shape and alignment of the teeth and oral hygiene standards.
To cause tooth decay, the interaction of the above factors occurs as follows:
Within seconds of eating food, a sticky coloured mass called plaque forms on the tooth surface which is colonized by bacteria and acts like a bio film on the tooth surface. In the absence of plaque removal mechanisms like tooth brushing, the resultant fermentation process causes demineralization of the enamel and a portal of entry is gained into the tooth causing extensive damage in the dentine as well. Without the support of the dentine, the undermined enamel caves inwards causing what you see as a cavity on the tooth. The common bacteria species in tooth decay are streptococcus mutans and lactobacilli species. The frequency with which teeth are exposed to carciogenic agents like sugars for example frequent snacking in between meals also increases the likelihood of demineralization and therefore decay. It therefore follows that the frequency and the effectiveness of plaque removal mechanisms like tooth brushing reduces the likelihood of decay.
Once the enamel is demineralized, the dentinal tubules which have passages to the nerve of the tooth become exposed which causes mild toothache (reversible pulpitis). This pain may worsen with exposure to heat, cold and sweet foods and drinks.
The symptoms may respond to pain medication at this point but if the caries progression continues unabated the pulp chamber of the tooth becomes involved and inflamed (irreversible pulpitis).
At this stage, the toothache will become severe and spontaneous in nature especially at night.
The decay progresses further still to involve the supporting periodontal tissues at the bottom of the tooth (periapical periodontitis) which may manifest as pain on biting especially the hard foods. With chronic infection, the pulp contents often die off with loss of vitality, (pulpal necrosis) and subsequent pus collection at the bottom of the root (abscess formation).
This may also cause facial swelling, and uncontained, the infection may spread to the other potential spaces in the head and neck region, the results of which may be catastrophic with some like Ludwig’s Angina resulting in severe airway embarrassment and may be fatal in the absence of emergency medical attention.
Like any other condition, the outcomes of treatment are better and less costly if detection is made early. In the early stages of the carious process, the process can only be halted by conservation of the tooth with restorations. Unfortunately, medication alone without restoration will not yield any long term relief.
Teeth which have extensive decay involving the pulp chamber will require more extensive (and more costly in terms of time and finances) treatment called root canal treatment which aims at removing all the living inflamed contents of the tooth. This is often done in three visits and when successful, the tooth should not hurt again. After root canal treatment, an artificial cover or crown to reignforce the tooth after root canal treatment to prevent tooth fracture is usually recommended.
For teeth with extensive decay where the tooth is not amenable to other conventional restorative procedures like root canal treatment, the tooth will have to be extracted (removed).
An assessment of the extent of decay is usually first made. Sometimes this may involve the use of dental x-rays. Your dentist will then be better placed to determine the course of action to avert the caries spread and restore your tooth to good function and aesthetics.
Prevention of tooth decay
- The most important aspect of prevention of tooth decay is oral hygiene; proper, meticulous and regular tooth brushing is key if plaque removal is to be effective. Pay particular attention to the back teeth, most especially the biting (occlusal surfaces) of the teeth. You’ll need about 2-5 minutes to effectively brush your teeth. Remember to use a toothbrush with softer bristles and replace this every after two months. Use minimum force to avoid hurting the gums; what’s important is that all surfaces of the teeth are cleaned and while you’re at it, remember to clean the tongue as well.
- Tooth paste contains fluoride which has been shown to impart resistance to enamel against caries attack; however this must complement thorough tooth brushing.
- Ask your dentist to show you how to use dental floss for Interdental cleaning. More often than not, the decay proceeds undetected from the side surfaces (approximal surfaces) of the teeth and therefore dental flossing is a very important part of your oral hygiene regime.
- A high sugar diet is recipe for caries disaster. Reduce on the amount of sugary snacks taken in between meals; sticky confectioneries tend to get easily trapped in the teeth and pause a higher risk. Contrary to popular belief, natural sugars have been found to be as equally carcinogenic as refined ones.
- For children avoid prolonged at will breast/bottle feeding particularly at night. Ensure that as a parent you get actively involved in their oral hygiene practice. If you have a sick child, ask your medical practitioner about syrup medications that contain non sugar sweeteners.
- Visit a dentist regularly (at least once every six months) for a dental check up and advice on your dental health. A stitch in time always saves nine (32 teeth in this case!)