context: Enamel is the thin outer covering of the tooth. This tough shell is the hardest tissue in the human body. Enamel covers the crown which is the part of the tooth that's visible outside of the gums. Because enamel is translucent, you can see light through it. But the main portion of the tooth, the dentin, is the part that's responsible for your tooth color -- whether white, off white, grey, or yellowish. Sometimes coffee, tea, cola, red wine, fruit juices, and cigarettes stain the enamel on your teeth. Regular visits to your dentist for routine cleaning and polishing can help remove most surface stains and make sure your teeth stay healthy. Enamel helps protect your teeth from daily use such as chewing, biting, crunching, and grinding. Although enamel is a hard protector of teeth, it can chip and crack. Enamel also insulates the teeth from potentially painful temperatures and chemicals. Unlike a broken bone that can be repaired by the body, once a tooth chips or breaks, the damage is done forever. Because enamel has no living cells, the body cannot repair chipped or cracked enamel. Tooth erosion happens when acids wear away the enamel on teeth. Enamel erosion can be caused by the following: Excessive soft drink consumption (high levels of phosphoric and citric acids) Fruit drinks (some acids in fruit drinks are more erosive than battery acid) Dry mouth or low salivary flow (xerostomia) Diet (high in sugar and starches) Acid reflux disease ( GERD) Gastrointestinal problems Medications (aspirin, antihistamines) Genetics (inherited conditions) Environmental factors (friction, wear and tear, stress, and corrosion) Friction, wear and tear, stress, and corrosion (or any combination of these actions) can cause erosion of the tooth surface. More clinical terms used to describe these mechanisms include: Attrition. This is natural tooth-to-tooth friction that happens when you clench or grind your teeth such as with bruxism, which often occurs involuntary during sleep. Abrasion. This is physical wear and tear of the tooth surface that happens with brushing teeth too hard, improper flossing, biting on hard objects (such as fingernails, bottle caps, or pens), or chewing tobacco. Abfraction. This occurs from stress fractures in the tooth such as cracks from flexing or bending of the tooth. Corrosion. This occurs chemically when acidic content hits the tooth surface such as with certain medications like aspirin or vitamin C tablets, highly acidic foods, GERD, and frequent vomiting from bulimia or alcoholism. More findings show bulimia as a cause of enamel erosion and tooth decay. Bulimia is an eating disorder that's associated with binge eating and vomiting, a source of acid. Frequent vomiting erodes tooth enamel and can lead to cavities. Saliva plays a key role in keeping teeth healthy and strong. Not only does saliva increase the health of the body tissues, it protects enamel by coating the teeth in protective calcium and other minerals. Saliva also dilutes erosive agents such as acid, removes waste material from the mouth, and boosts protective substances that help fight mouth bacteria and disease. In a healthy mouth, calcium-rich saliva helps strengthen teeth, even if you drink an acidic soda or juice. Yet when you go overboard and ingest a lot of acidic foods and beverages, this strengthening process on the teeth no longer occurs. Plaque is a sticky film made up of saliva, food particles, bacteria, and other substances. Plaque forms between your teeth and gets inside tiny holes or pits in the molars. It also gets around your cavity fillings and next to the gum line where the teeth and gums meet. Sometimes the bacteria in plaque changes food starches into acids. When this happens, the acids in plaque start to eat away at the healthy minerals in the tooth enamel. This causes the enamel to wear down and become pitted. Over time, the pits in the enamel increase and grow in size. The signs of enamel erosion can vary, depending on the stage. Some signs may include: Sensitivity. Certain foods (sweets) and temperatures of foods (hot or cold) may cause a twinge of pain in the early stage of enamel erosion. Discoloration. As the enamel erodes and more dentin is exposed, the teeth may appear yellow. Cracks and chips. The edges of teeth become more rough, irregular, and jagged as enamel erodes. Severe, painful sensitivity. In later stages of enamel erosion, teeth become extremely sensitive to temperatures and sweets. You may feel a painful jolt that takes your breath away. Cupping. Indentations appear on the surface of the teeth. When enamel erodes, the tooth is more susceptible to cavities or tooth decay. When the tooth decay enters the hard enamel, it has entry to the main body of the tooth. Small cavities may cause no problems at first. But as cavities grow and penetrate the tooth, they can affect the tiny nerve fibers, resulting in an extremely painful abscess or infection. To prevent enamel loss and keep teeth healthy, be sure to brush, floss, and rinse with a fluoride and antiseptic mouthwash daily. See your dentist every six months for regular checkups and cleaning. You can also try the following: Eliminate highly acidic foods and drinks from your diet such as carbonated sodas, lemons, and other citrus fruits and juices. Rinse your mouth immediately with clear water after eating acidic foods or drinking acidic drinks. Use a straw when you drink acidic drinks. The straw pushes the liquid to the back of your mouth, avoiding your teeth. Monitor snacks. Snacking throughout the day increases the chance of tooth decay. The mouth is acidic for a few hours after eating foods high in sugar and starches. Avoid snacking unless you're able to rinse your mouth and brush teeth. Chew sugar-free gum between meals. Chewing gum boosts saliva production up to 10 times the normal flow. Saliva helps strengthen teeth with important minerals. Be sure to select sugar-free gum with xylitol, which is shown to reduce acids in beverages and foods. Drink more water throughout the day if you have low saliva volume or dry mouth. Use fluoride toothpaste. Fluoride strengthens teeth, so make sure fluoride is listed as an ingredient in your toothpaste. Ask your dentist if sealants may be helpful in preventing enamel erosion and tooth decay. Yes, it is possible to get too much fluoride. While fluoride is useful in preventing tooth decay, too much fluoride can cause problems like enamel fluorosis. This condition can occur in children and causes defects in the enamel of the teeth. Children with enamel fluorosis may have ingested too much fluoride through supplements, or they took fluoride supplements in addition to drinking fluoridated water. Also, swallowing fluoride toothpaste increases the chances of enamel fluorosis. Most children with enamel fluorosis have mild conditions that are not a reason for concern. Yet in some severe cases, the teeth are discolored, pitted, and difficult to keep clean. Treatment of tooth enamel loss depends on the problem. Sometimes tooth bonding is used to protect the tooth and increase cosmetic appearance. If the enamel loss is significant, the dentist may recommend covering the tooth with a crown or veneer. The crown may protect the tooth from further decay.