Dental caries is caused by bacterial damage to teeth from plaque and acid production when exposed to fermentable carbohydrates like sugar. The major bacteria involved are Streptococcus mutans and lactobacilli, which adhere to teeth and produce acid from sugars, lowering the pH and demineralizing enamel and dentin. If left untreated, caries can spread to the pulp, causing inflammation and pain. Consequences of untreated dental caries include local infections and possible systemic illnesses.