Good bacteria can kick out cavity-causers


The search for the Holy Grail in dentistry has been to find a vaccine for cavities.

Like any quest, there have been many twists and turns along the way. Could dental research now be close to having the long sought-after vaccine against this major health concern?

Researchers’ efforts have focused on one bad bacterium in particular: Streptococcus mutans. This bacterium, and a few lesser cousins, is thought to cause most dental decay.

As a short review, the prevailing theory about what causes dental decay is the so-called “acid theory.” When the mouth’s bacterial communities are fed sugary foods, a few vile characters show their thanks by spewing acid on your teeth. This acid dissolves the minerals in the teeth, creating unsightly decay. (Incidentally, people can bypass the bacteria and apply acid directly to their teeth in the form of beverages such as soda, Gatorade and even Snapple iced tea).

Efforts to eradicate these few bad bacteria have traditionally focused on carpet-bombing all bacteria in the mouth with hydrogen peroxide, Listerine or other mouthwashes.

However, scientists are coming to the realization that maintaining friendly bacterial communities is much preferable to simply eradicating them. When all bacteria are removed, the body may struggle to regain its equilibrium. Anyone who has gone through multiple courses of antibiotics will know exactly what I’m talking about.

Probiotics appear to be the most effective way to repopulate the intestinal tract with friendly bacteria, but could the same concept apply to the mouth’s microbes?

From the moment we are born, microbes populate our mouths. The question is: How do we encourage healthy bacteria to call the mouth home and crowd out the unhealthy ones?

Studies from Helsinki, Finland, have shown that kids fed a probiotic yogurt containing lactobacilli had a measurable reduction in new cavities. (Journal of Applied Microbiology, 2004.)

What appears to be happening is bacteria like to live in cozy communities called a biofilm. The growth of healthy biofilm communities is promoted by lactobacilli, commonly found in yogurt. Good bacteria, in sufficient quantities, muscle out the bad guys, leaving no place for them to attach their sticky fingers to your teeth.

Enter Dr. Jeffrey D. Hillman. He has been working on a caries (decay) vaccine for more than two decades. His research group developed a strain of Streptococcus mutans that doesn’t cause cavities. The name they gave their creation was SMaRT or S.Mutans Replacement Therapy.

The concept behind Replacement Therapy oral probiotics is to introduce new and friendly bacteria to crowd out the evildoers instead of destroying all bacterial life with harsh mouthwashes or antibiotics.

“SMaRT Replacement Therapy is designed to be applied topically to the teeth by a dentist, pediatrician or primary-care physician during a routine office visit. A suspension of the SMaRT strain is administered using a cotton-tipped swab during a single five-minute, pain-free treatment. Following treatment, the SMaRT strain should displace the native, decay-causing S. mutans strains over six to 12 months and permanently occupy the niche on the tooth surfaces normally occupied by native S. mutans.”

Note: SMaRT is still in clinical trials but hopefully will be available soon for use by dentist/pediatrician. Read more

While conducting research on the vaccine for decay-causing bacteria, it occurred to Hillman to survey the types of microbes found in healthy mouths. From that research he found specific varieties are associated with people who have very healthy mouths. From this epiphany he and a colleague have developed a company called Oragenics.

Their company now markets three probiotic products: A berry-flavored probiotic lozenge for children called Evorakids intended to establish healthy flora while kids are young; a probiotic mint called EvoraPlus that is intended to re-establish and maintain the health of adults’ gums, teeth and breath; and a third type called EvoraPro that is available only from your dental office.

EvoraPro is intended for short-term use after deep cleanings to re-establish healthy flora for the gums and would be followed up by daily use with EvoraPlus for maintaining a healthy equilibrium.

Are probiotics the long-sought-after dental cavity vaccine?

Don’t throw away your toothbrush just yet. As we have been searching for a vaccine, it’s become apparent that what causes dental decay is much more complicated than one single bacterium. Its development depends on what medications we take, what we eat and drink, our stress level, heredity and, most importantly, how well we clean our teeth at home.

As part of an overall plan to keep the mouth healthy I believe we will see increased use of probiotics, but the key to a healthy mouth is an accumulation of healthy habits, and regular dental visits.

Dr. Eric Gustavsen practices dentistry at Southpoint Dental Center, 1129 S. Second Ave. More information on his practice can be found at


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