Although asymptomatic at first, if left untreated they will cause tooth discoloration, pain, and abcess. Modern treatment is to drill out the diseased part of the tooth and re-fill it with acid resistant material, usually an alloy containing mercury for teeth that bear a heavy load (like molars) or a ceramic compound (where cosmetic considerations are more important, such as on front teeth). However, prevention is also important. Dentists recommend avoiding sugary or acidic foods, regular brushing with a fluoride based toothpaste, and flossing to remove the plaques that form between the teeth that harbor bacteria.