Cavities (Tooth Decay)

Early decay can be clinically invisible. A first visible sign may be a white spot from mineral loss beneath the enamel. As a cavity grows, it can cause pain or sensitivity, particularly when it is close to the nerve. Children may have difficulty eating, speaking, playing or learning when decay is painful.

Plaque bacteria use fermentable carbohydrates such as glucose, fructose, maltose and sucrose to make organic acids. Repeated acid attacks lower the biofilm pH, soften the tooth surface and drive demineralisation. Frequent sugar exposure and too little fluoride make this process more likely.

Decay may begin as mineral loss without a hole. If the process continues, the enamel surface can soften and a visible cavity can form. Progression into deeper tooth structure brings the nerve closer to the infection and changes the treatment needed.

Risk rises when plaque remains on teeth, sugary foods or drinks are consumed frequently, or fluoride exposure is insufficient. Behavioural, psychological and social factors also affect the disease process.

A check-up can identify white, brown or black staining, a hole, or soft and sticky tooth areas. An X-ray can reveal decay that is not visible on the surface.

Before a hole forms, fluoride may reverse early decay. Non-invasive care can include remineralisation, plaque removal and sealing. Once a cavity has formed, decayed tissue is removed and the tooth is restored with a filling; conservative repair is preferred where possible.

Care ranges from fluoride and other non-invasive measures for early mineral loss to a filling after tooth structure has been lost. Greater loss of structure changes the procedure required.

A cavity can enlarge, cause pain and sensitivity, and eventually lead to tooth loss. If decay reaches the nerve, an abscess may form and infection can spread through the body; severe spread is rare but can be life-threatening.

Brush twice daily with fluoride toothpaste, clean between the teeth, limit sugary drinks and foods, avoid tobacco, and keep regular check-ups and professional cleanings. Fluoride toothpaste, mouth rinse, fluoridated water and sealants can help prevent or slow decay.