Mix of bacteria, sugars and acid leads to cavities

"How do we get cavities?" asked a young patron from Grayslake Area Public Library District.

Teeth are coated in the hardest body substance, calcium phosphate-laden enamel. It's harder than steel but more brittle.

Teeth need that protective coating so they can do their job - break down food so your body can absorb nutrients.

Teeth also play a significant role in speech; sounds and words are produced when the mouth, tongue and teeth work in concert.

The mouth hosts more than 500 species of bacteria. As Dr. Mary Chiakulas, dentist at McHenry Dental Associates explains, sugars in your mouth are the David to the Goliath of tooth enamel.

"Bacteria takes in sugars from your mouth, using that for energy, and the byproduct is acid, which breaks down the enamel in your teeth," Chiakulas said.

Acids cause demineralization, which can lead to decay known as cavities. If you've got tooth decay, you might sense pain or sensitivity to heat, cold or sweet. But sometimes there are no signs. Chiakulas said that's why patients need X-rays once a year, so a dentist can closely examine each tooth and identify sites where holes might be occurring.

Decay is demineralization. Remineralization can occur to prevent tooth decay. Minerals from foods and water can reinforce enamel. Tap water that contains fluoride, a natural mineral, helps stop the acidification process that bacteria need to break apart the enamel. The U.S. Centers for Disease Control reports people encounter 25 percent fewer cavities when they live in communities where fluoride is added to the tap water when compared to people who have no fluoride additive.

When repairs are needed, a dentist mechanically removes the decay and replaces it with material that's a mix of plastic and a bonding agent. Chiakulas said in many cases, this repair will last 20 years.

Cavities can be kept to a minimum by brushing at least twice each day with fluoride toothpaste and flossing regularly. Two trips each year to the dentist should help take the bite out of tooth decay.

Cows, camels and caribou, and tens of thousands of vertebrates have teeth encased in enamel, just like humans. But animals rarely have cavities, as Dr. Mike Adkesson, vice president of clinical medicine for the Chicago Zoological Society, explains.

Adkesson works with every animal at the zoo that has teeth, including alligators.

"The bigger problem is recession of the gum at the base of the tooth and infections that occur with tartar buildup," he said.

Adkesson said this is called periodontal disease and occurs more often in older animals.

"Occasionally, our dogs might fracture or chip a tooth," Adkesson said, referring to Brookfield Zoo's two Labrador retriever police dogs. "Chewing bones can sometimes take a toll."

Check it out

The Grayslake Area Public Library District suggests these titles on teeth:

• "Alan's Big, Scary Teeth" by Jarvis

• "Open Wide! The Ultimate Guide to Teeth" by Susan Grigsby

• "All About Teeth" by Mari C. Schuh

• "What if You Had Animal Teeth?" by Sandra Markle

• "You Wouldn't Want to Live Without Dentists!" by Fiona Macdonald