It is most prominent on the grooved chewing surfaces of back molars, just above the gum line on all teeth, and at the edges of fillings. Plaque and calculus irritate the gums, resulting in gingivitis . Acids begin to dissolve tooth enamel within 20 minutes after eating, the time when most bacterial activity occurs. Untreated tooth decay can result in death of the internal structures of the tooth with eventual loss of the tooth. The type of carbohydrate and the timing of ingestion are more important that the amount.
Sticky foods are more harmful than nonsticky foods because they remain on the surface of the teeth.
Frequent snacking increases the time that acids are in contact with the surface of the tooth. Most dental caries are discovered in the early stages during routine checkups. The surface of the tooth may be soft when probed with a sharp instrument. Pain may not be present until the advanced stages of tooth decay. Dental X-rays may show some cavities before they are visible to the eye.