Frequently when I see a two-year-old for a well child visit, I exclaim, “Oh my –- your child has cavities between all his baby molars!” The parents wonder, “How can that be?”

If your child eats a lot of sticky foods, she may be at risk for cavities between the teeth. Dr. Martha Ann Keels, a pediatric dentist at Duke Children’s, explains why these foods often cause cavities in children and how to prevent them.

-- Dennis Clements MD, PhD, MPH

Have you ever used a toothpick or your fingernail to remove food from between your teeth? Many children do not develop the sensation of something being caught between their teeth until they are grooming to go out on a date. That can lead to problems with cavities between teeth, especially if the child frequently eats sticky foods.

Unfortunately, many parents start their children’s day with a gooey breakfast bar and gummy vitamins. Both items are very cariogenic (cavity causing) and sticky. These foods collect on top of and between the molars (the teeth in the back of the mouth that they chew with).

The Beginning of Tooth Decay

Figure one (courtesy of Dr. Ted Croll) shows the molars of a young child with dried fruit snacks caught between the teeth and on the top surface of the molars. If the dried fruit snacks are left in contact with the enamel, the process of tooth decay begins.

Figure 1

The sticky food serves as a carbohydrate source for cariogenic bacteria, which in turn process the sugars into lactic acid via glycolysis. It is the lactic acid that breaks down the enamel of the teeth, resulting in cavities.

It can be a very upsetting dental visit when parents of a four-year old hears from the dentist that their child has multiple cavities between the primary (baby) molars.

Around age four, the back primary molars drift in closer proximity and touch each other therefore requiring the dentist to take bitewing radiographs to visualize between these teeth.

Prior to age four, the molars should have space between them allowing the dentist to easily visualize all sides of the teeth. Humans do the majority of their chewing with their molars. If a child is chewing more sticky sugary foods or candies, the risk of developing cavities between the molars increases.

In figure 2, you can see a left bitewing radiograph of a four year old demonstrating four cavities (dark radiolucent areas) in between her four primary (molars). The right side of her mouth had the same disease process. She had eight cavities in total between all of her baby molars. The white areas on the top of her molars indicate she has had previous fillings in the grooves on the chewing surfaces of her teeth.

Figure 2

Many people do not realize the risk of having foods caught between their teeth, which can result in several interproximal (in between the teeth) cavities. (Cavities require local or general anesthesia and fillings to repair, which will prevent a future significant infection in the jaw).

Dentists cannot detect this type of tooth decay without radiographs. Tooth brushing alone cannot prevent these types of cavities.

Avoiding Cavities

To remove food particles from between teeth, one must floss. American Academy of Pediatric Dentists (AAPD) recommends that parents should start flossing their child’s teeth when any two teeth are touching and continue to do so until approximately age eight when the child has sufficient dexterity to assume the responsibility of self-flossing.

In providing healthy lifestyle suggestions for parents, it is helpful to use the AAP prevention message of “ 5-2-1-0” -- eating five fresh fruits and vegetables everyday, two hours or less of screen time, one hour or more of physical activity, and zero sugared drinks.

However, a health care provider must be diligent in asking if the caregiver is feeding “fresh” fruit, as many parents are substituting processed fruit, such as dried fruit snacks, fruit roll-ups, and fruit-by-the-yard for fresh fruit as the fruit choice for their child. These types of non-fresh fruit snacks create a high caries (the process that causes cavities) risk.

A better choice for a snack is fresh fruit (sliced apples or banana) or vegetables (celery sticks, carrots). For the occasional sweet treat, one that melts, such as a scoop of ice cream, a Hershey Kiss, or M&Ms is a better choice as this type of treat does not adhere to the enamel. If it melts readily on your hand, it will easily melt off of the teeth.

Pediatricians and their staffs can help encourage healthy eating habits and good oral hygiene rituals including flossing between any two teeth that touch. They can also encourage avoiding sticky snacks and candies and limiting the frequency of even the “better” sugary treats. “All things in moderation” applies to treats as well.

-- Martha Ann Keels, DDS, PhD, is a pediatric dentist with Duke Department of Pediatrics's Division of Pediatric Dentistry.

-- Dennis Clements, MD, PhD, MPH, is the chief of primary care pediatrics at Duke Children's Hospital.