PreviDent is a prescription-strength toothpaste that delivers 5,000 parts per million (ppm) of fluoride, roughly four to four and a half times the amount found in regular over-the-counter toothpaste. Dentists prescribe it to prevent cavities in people whose teeth face higher-than-normal risk of decay, including those with dry mouth, exposed root surfaces, or a recent history of frequent cavities.
How PreviDent Strengthens Teeth
Every time you eat or drink something acidic, the minerals in your tooth enamel start to dissolve. Fluoride reverses that process. It reacts with the calcium in your enamel to form a compound called fluorapatite, which is harder and more acid-resistant than the original enamel mineral. This means your teeth can withstand a lower pH before they start to break down.
At the 5,000 ppm concentration in PreviDent, fluoride does two things more aggressively than a standard toothpaste can. First, it drives minerals back into weakened spots on the tooth surface, a process called remineralization. Second, it interferes with the metabolism of plaque bacteria, slowing their growth and reducing the amount of acid they produce in the first place. Regular toothpaste (typically 1,000 to 1,500 ppm fluoride) offers some of this protection, but the higher dose in PreviDent is measurably more effective for people already losing ground to decay.
Who Gets Prescribed PreviDent
PreviDent is approved for adults and children age 6 and older. Dentists typically prescribe it for patients at elevated risk for cavities rather than as a routine upgrade from store-bought toothpaste. Common reasons include:
- Dry mouth (xerostomia): Saliva naturally neutralizes acid and delivers minerals to teeth. Medications for blood pressure, depression, allergies, and many other conditions can reduce saliva flow, leaving teeth vulnerable.
- Root surface exposure: Receding gums expose the roots of teeth, which lack the thick enamel that protects the crown. Root surfaces decay more easily.
- History of frequent cavities: If you’ve had multiple new cavities in a short period, a dentist may prescribe PreviDent to shift the balance back toward repair.
- Orthodontic treatment: Braces create hard-to-clean areas where plaque accumulates, raising the risk of white spot lesions and decay around brackets.
- Radiation therapy to the head or neck: Radiation can permanently damage salivary glands, creating extreme dry mouth that leads to rapid tooth breakdown.
Evidence for Root Decay
Root cavities are one of the most common reasons PreviDent gets prescribed, particularly for older adults. A systematic review in the Journal of Clinical and Diagnostic Research found that brushing twice daily with 5,000 ppm fluoride toothpaste significantly improved the surface hardness of root cavities compared to standard 1,350 ppm toothpaste. In one of the studies reviewed, patients using 5,000 ppm fluoride averaged about 1 active root cavity at follow-up, while those using regular-strength fluoride averaged 2.5. The higher-concentration group also had far more arrested (stopped) cavities: 2.3 per person versus 0.6, meaning damage that had already started was halted and partially reversed.
PreviDent Formulations
PreviDent comes in several versions, all containing 1.1% sodium fluoride (5,000 ppm). The differences are in the additional ingredients and flavor profiles.
The standard PreviDent 5000 Plus is a straightforward high-fluoride toothpaste. PreviDent 5000 Sensitive adds potassium nitrate, an ingredient that calms the nerves inside teeth to reduce pain from sensitivity to hot, cold, or sweet foods. PreviDent 5000 Booster Plus and a version designed for children (PreviDent 5000 Kids) round out the line. The kids’ version still carries the same fluoride concentration but comes in a milder flavor. Regardless of formulation, all are prescription-only.
How to Use It
PreviDent replaces your regular toothpaste once a day, usually at bedtime. You apply a thin ribbon to your toothbrush and brush for two minutes. After brushing, spit the toothpaste out but do not rinse your mouth, eat, or drink for 30 minutes. This waiting period lets the fluoride continue to absorb into your enamel. For children between 6 and 16, the instructions differ slightly: they should rinse their mouth thoroughly after spitting to limit the amount of fluoride swallowed.
Most people continue using their regular over-the-counter toothpaste for their other daily brushing. PreviDent is the nighttime replacement, not an addition on top of your normal routine.
Safety Considerations for Children
PreviDent is not recommended for children under 6 unless a dentist or physician specifically directs it. Young children tend to swallow toothpaste during brushing, and repeated ingestion of high-fluoride paste can cause dental fluorosis, a condition where developing permanent teeth form with white spots or, in severe cases, pitting. The risk is higher in areas where the drinking water already contains fluoride above 0.6 ppm.
Accidental ingestion of a large amount can cause more immediate symptoms: burning in the mouth, nausea, vomiting, diarrhea, and abdominal cramping, typically within 30 minutes. These symptoms can persist for up to 24 hours. Keeping the tube out of reach of small children is important, just as you would with any prescription medication.
What to Expect Over Time
PreviDent is not a short-term fix. Most dentists prescribe it as an ongoing part of your oral care routine for as long as the risk factors persist. If you were prescribed it because of dry mouth from a medication you take daily, for example, you’ll likely use it for as long as you’re on that medication. If you’re using the Sensitive formulation, you may notice reduced tooth sensitivity within a few weeks of consistent use, though the cavity-prevention benefit builds gradually as weakened enamel re-hardens over months of exposure.
PreviDent works best alongside good brushing habits, flossing, and limiting sugary or acidic foods. It gives your teeth a significant chemical advantage, but it cannot overcome poor oral hygiene on its own.