Dental caries is a progressive disease in which the acid produced by plaque bacteria weakens and destroys the tooth enamel. Also known as tooth decay, caries begins with excessive demineralisation of the enamel, and can lead to a dental cavity, or a hole in the tooth, and eventual tooth loss. Despite being preventable, caries is the most prevalent disease worldwide.
Some oral bacteria produce acid by-products that break down and release minerals in the tooth (demineralisation).
This weakens the enamel, but saliva helps to restore lost minerals and strengthen the tooth (remineralisation). In those with high-sugar diets and/or inadequate oral hygiene, bacteria can accumulate on the teeth in a sticky layer called plaque. When exposed to carbohydrates, plaque bacteria continuously demineralise the enamel, exceeding our ability to remineralise. A net loss of minerals occurs, leading to the destruction of enamel.
Early-stage caries presents as a white spot, or incipient carious lesion, beneath the surface of the tooth. Only, when the lesion breaks through the enamel surface, it causes a cavity in the tooth. As caries advances, the cavity can reach the dentine and, later, the pulp. This can cause severe pain for the patient, and can ultimately lead to tooth loss or abscess.
A carious lesion can form anywhere on the tooth, but it is most likely to occur on the biting surfaces (occlusal caries), in the spaces between the teeth (interproximal caries) or along the gingival margine. In patients with exposed dental roots, caries is especially dangerous, as it progresses much faster in dentine (root caries) and is harder to control.
Dental caries is the most prevalent oral disease worldwide, affecting both adults and children. It is estimated that 2.3 billion people have caries of the permanent teeth, and 530 million children have caries of the decidious teeth.
Anybody can suffer from caries. Strong preventative programs achieved a massive reduction of cavities during early childhood. In many areas in Europe, caries in children is seen in a minority of children, often associated with their socio-economic status and their parent's knowledge about oral health (constant suckling on milk bottles during night). Despite the preventative achievements during childhood, most people still suffer from cavities during their adhult life when preventative activities are reduced or new risk factors occur, such as:
- Poor oral hygiene
- Increased consumption of carbohydrates
- Frequent snacking
- Xerostomia (dry mouth)
- Radiation of head and neck (cancer treatment)
- PUFAs (visible pulp, ulceration, fistula, abscess)
In the early stages of caries, the patient is unlikely to know they have an incipient carious lesion unless told by their dental professional. However, as caries progresses, the patient will experience increasingly painful symptoms.
By the time the cavity reaches the dentine of the tooth, the patient will likely be experiencing some degree of tooth pain and/or sensitivity. If the cavity reaches the pulp or an abscess develops, the patient will likely be in extreme pain.
The pain of dental caries can be emotionally distressing and may make it more difficult to talk, eat or sleep. In cases of visible tooth decay or tooth loss, e.g. decay of the front teeth, the patient may also experience difficulties with confidence and self-esteem.
Treatment for advanced caries, such as root canal or extraction, can be painful and traumatic for the patient. Caries is often associated with other dental complications that require additional treatment, such as gingivitis and periodontitis.
While subsidised NHS dental care can help with the cost of caries treatment, it will only cover restorative work in certain circumstances. Caries patients who wish to repair extensive damage or replace lost teeth may be unable to do so due to the high cost.
Caries can be prevented by keeping dietary sugar and snacking to a minimum, and practicing good oral hygiene. Brushing twice a day with a fluoride toothpaste and cleaning in between the teeth with floss or interdental brushes can prevent the build-up of plaque that leads to caries.
After more than 50 years, fluoride containing toothpastes are still the gold standard for caries prevention. It is proven to be effective and safe in many independent studies and helped us to achieve the massive reduction in cavities in the past decades. Emerging technologies will help us to further increase the effectivity of fluoride toothpaste, for example through the pre-biotic effect of arginine.
If caries is detected at an early stage, it can be halted and even reversed. In patients with low caries risk, a slight change in their behaviour and improvement of their oral care habits can shift the balance to increased remineralisation and therefore reverse the damage done.
In patients with an increased risk for caries progression, a more powerful intervention might be needed. There are different high-fluoride treatments available that can help your patients stay cavity free until the underlying risk factors can be mediated:
- Fluoride varnishes can be applied in office, even in young children, to counteract the caries risk and help remineralising existing incipient caries lesions without additional effort from the patient.
- For patients with good compliance high fluoride toothpastes with 2800 and 5000 ppm fluoride to be used at home instead of a regular toothpaste offer superior caries prevention vs a regular toothpaste.
- Specialized mouthrinses are additional solutions to effectively manage the increased caries risk .
Once a lesion has progressed into a cavity, the damage to the enamel cannot be reversed naturally. Decayed enamel and/or dentine must be removed and the cavity filled. If the cavity has reached the pulp, a root canal or an extraction is usually required.