Caries causes
Dental caries starts when plaque bacteria use sugars to make acids that remove minerals from tooth enamel and dentine.
The short answer
Dental caries starts when plaque bacteria use sugars to make acids that remove minerals from tooth enamel and dentine. Repeated acid attacks can create a cavity that reaches the pulp.

What is the direct answer?
What does this question mean?
Caries is a process, not simply a hole. Plaque collects on tooth surfaces, bacteria metabolise fermentable carbohydrates, and the resulting acids lower the pH at the enamel surface.
What can you do next?
Brush twice daily with fluoride toothpaste, clean between teeth, and keep sugary foods and drinks to mealtimes rather than frequent exposures. A dentist can remove softened tooth tissue and restore the shape with a filling when a cavity has formed.
When should you seek dental care?
Book an examination for a white, brown, or black spot, a rough edge, food trapping, sensitivity, or pain. Swelling, spontaneous pain, or pain that wakes you may indicate deeper inflammation and needs prompt assessment.
What should you ask the dentist?
Ask whether the lesion is active caries, how deep it is, and whether fluoride treatment, monitoring, or a restoration is appropriate. Ask how the affected surface can be cleaned and what dietary pattern is increasing acid attacks.
Frequently asked questions
Can a cavity form without pain?
Yes. Early or moderate caries may have no noticeable symptoms, which is why examinations matter.
Can brushing repair a hole?
Brushing supports remineralisation of early enamel changes, but a formed cavity generally needs an assessment and restorative care.
