CJ Henley, DMD, PA / San Marco, Jacksonville, Florida
Fluoride trays and radiation caries in Jacksonville, FL.
A few minutes a day to protect the teeth radiation puts at risk.
Radiation caries is fast, widespread tooth decay that can follow head and neck radiation, mostly because saliva drops off. The main defense is prescription-strength fluoride every day, often in custom trays. Dr. Henley makes fluoride trays and follows radiation patients at our San Marco office, and he’s the one who sees you at every visit.
- 3 monthsafter radiation is when rapid decay may begin if saliva stays low2
- Dailyprescription-strength fluoride is the recommendation after head and neck radiation1
- 572patients in a study where daily fluoride use was tied to less new decay after radiation3
- 1 dentistsees you at every visit, from the tray fitting to each checkup
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Radiation caries and radiation decay
Why teeth can seem to fall apart after radiation.
Radiation caries is tooth decay that develops quickly after head and neck radiation. The biggest reason is lost saliva, which normally rinses teeth, neutralizes acid, and repairs early damage. It tends to show up along the gumline, on the biting edges of front teeth, and on smooth surfaces where ordinary cavities rarely start.
People often tell us their teeth started breaking at the gumline a year or two after radiation, though they never had many cavities before. Researchers describe radiation caries as having several causes working together.4
Why it moves so fast
- Less saliva. When the salivary glands are in or near the radiation field, saliva can drop sharply, and for many people that loss is permanent.4 Without it, acid from food and bacteria sits on the teeth much longer.
- Changes in the teeth themselves. Whether radiation directly weakens enamel and dentin is still debated. One study of extracted teeth found the decay itself looked much like ordinary decay, which suggests saliva loss matters more.5
- Changes in how you eat. Sore mouths, taste changes, and dry mouth push many people toward soft foods, nutritional shakes, and frequent sips of sweet drinks. Each one feeds decay-causing bacteria.
Where it shows up
- At the gumline (the cervical area), sometimes wrapping around the tooth.
- On the biting edges of front teeth, a spot that rarely decays otherwise.5
- On smooth surfaces, often first as brown or chalky discoloration.5
A tooth that breaks off at the gumline after radiation isn’t just a cosmetic problem. If it has to come out, the extraction carries a lifelong risk of osteoradionecrosis. That’s why preventing decay matters so much.
Radiation decay timeline
When the risk starts, and how long it lasts.
Fluoride should start before or as radiation begins, not after decay shows up. Rapid decay may begin within about three months after radiation ends if saliva stays low.2 In one large study, new decay kept adding up over the two years after radiation.3 For people with lasting dry mouth, the risk is lifelong.
| Stage | What’s happening | What we focus on |
|---|---|---|
| Before radiation | Teeth are checked and treated; trays are made | A pre-radiation dental exam, fillings and cleanings, custom fluoride trays, and starting daily fluoride2 |
| During radiation | Mouth sores, taste changes, saliva starting to drop | Keeping the mouth clean and comfortable, and keeping up with fluoride as much as a sore mouth allows |
| First months after | Saliva often at its lowest; decay may begin within about three months2 | Frequent checkups, catching early soft spots, reinforcing the daily routine |
| Years after | Dry mouth may persist; decay risk continues | Daily fluoride for life, regular recall visits, and saving teeth instead of extracting when it’s reasonable1,2 |
Custom fluoride trays in Jacksonville
Daily high-strength fluoride is the cornerstone.
The 2024 ISOO-MASCC-ASCO guideline recommends prescription-strength topical fluoride applied to the teeth every day to lower the risk of decay after radiation.1 Most often that means a 1.1% sodium fluoride gel, about 5,000 ppm fluoride, used in custom trays or brushed on. For people with lasting dry mouth, it’s daily for life.2
Regular over-the-counter toothpaste has about a quarter of that fluoride, or less. That’s plenty for most people, but not enough once saliva has dropped. Rinses aren’t considered a substitute for a high-strength gel in this situation.2 A review of fluoride studies in radiation patients found fluoride does prevent radiation caries, while noting that the ideal product and schedule still need more research.8
Trays or brush-on?
- Custom trays. Thin, soft trays made from a mold or scan of your teeth. They hold the gel against every surface, including the gumline, for several minutes. NIDCR describes tray delivery as the recommended method.2
- Brush-on gel or paste. A prescription 5,000 ppm product brushed on after your regular brushing and flossing. It’s a reasonable option for people who can’t tolerate trays or have only a few teeth.2 Some people use both.
The right choice depends on how many teeth you have, how dry your mouth is, how wide you can open, and what you’ll actually do every day. If you have porcelain crowns or tooth-colored fillings, ask whether a neutral sodium fluoride gel is the right choice for you.2
Fluoride gel is a prescription medication. Use the product, amount, and timing your dentist gives you, and don’t swallow it.
How to use fluoride trays
Step by step, once a day.
Brush and floss first, put a thin ribbon of gel in each tray, wear the trays for the time your dentist recommends, then spit out the extra without rinsing. Wait about 30 minutes before eating, drinking, or rinsing. Most people fit it in before bed. These are general steps; follow the instructions Dr. Henley gives you.
Brush and floss first.
Plaque left along the gumline blocks the gel from the spots that decay first.
Put a thin ribbon of gel in each tray.
Run a thin line of gel along the inside of the tray where the teeth sit.2 You don’t need to fill it. Too much just squeezes out onto your gums and gets swallowed.
Seat the trays and wait.
Press them gently into place. Wear them for the time you’re given, commonly about 5 to 10 minutes. NIDCR’s instructions use 10 minutes.2 Don’t sleep in them unless you’ve been told to.
Take them out and spit.
Spit out the extra gel. Don’t rinse.2 The thin film left behind keeps working.
Wait about 30 minutes.
No eating, drinking, or rinsing for about half an hour, or as directed. Doing it at bedtime makes this easy.
Rinse and store the trays.
Rinse the trays with cool water, let them dry, and keep them in their case. More on tray care below.
Tray care and adherence
Keeping trays in shape, and keeping the habit.
Rinse trays with cool water after each use, keep them dry in a case, and keep them away from heat and pets. Replace them when they stop fitting, especially after new crowns, fillings, or extractions. The habit matters more than the trays. Studies tie daily fluoride use to less new decay after radiation.3,6
Caring for your trays
- Rinse with cool water. Hot water can warp the plastic. A soft brush and a little mild soap work for buildup.
- Store them dry, in a case. A closed case keeps them clean and out of reach of dogs, who seem to love chewing them.
- Bring them to checkups so we can check the fit.
When trays need replacing
A new crown, a large filling, a lost tooth, or slow shifting can change the fit. If a tray rocks, pinches, won’t seat, or splits, call us. A loose tray lets gel leak away from the gumline.
Why sticking with it matters
In a study that followed 572 people for two years after head and neck radiation, those who used fluoride daily and kept up with brushing and flossing had noticeably less new decay.3 An Australian study found the same thing: people who skipped daily fluoride, dental visits, hygiene advice, or diet advice were more likely to get new cavities.6
Fatigue after cancer treatment is real. If you’re skipping days, tell us. Switching to a brush-on product or fixing a tray that pinches is sometimes enough.
Beyond fluoride
Other things that help protect your teeth.
Fluoride does the heavy lifting, but it works better alongside a few other habits: managing dry mouth, choosing sugar-free options, changing how you sip, and seeing your dentist more often than twice a year. None of these replace daily fluoride. They add up.
Saliva substitutes and dry mouth care
Saliva substitute sprays, gels, and rinses can make a dry mouth more comfortable, and a prescribed saliva stimulant may help some people.2 Sipping plain water through the day helps too. See our dry mouth page for more.
Sugar-free gum and mints
Chewing sugar-free gum or sucking sugar-free mints can coax out whatever saliva your glands still make. Many are sweetened with xylitol, which mouth bacteria can’t use the way they use sugar.
How you sip matters
Sweet coffee, soda, juice, sports drinks, or nutritional shakes sipped over hours keep teeth bathed in sugar and acid. If you need shakes for calories, drink them in one sitting, then swish with water.
More frequent checkups
Decay after radiation can move fast, so many people need checkups and dental cleanings more often than twice a year. NIDCR suggests visits every 4 to 8 weeks for the first six months after radiation.2 Dr. Henley sets your interval based on what he sees.
Treating radiation caries
Fixing decay, and why we work hard to save teeth.
Small radiation caries spots are usually filled, often with glass ionomer or composite. Each material has tradeoffs in a dry mouth. Larger damage may need a crown or a root canal. After high-dose radiation to the jaw, saving a tooth is usually safer than removing it, because extraction can trigger osteoradionecrosis.1
Filling materials in a dry mouth
- Glass ionomer. Releases fluoride and is often chosen for gumline cavities. In a two-year study of irradiated patients with dry mouth, glass ionomer helped hold back new decay at the edges but wore away more easily.7
- Composite resin. Held its shape better in that same study, but did less to prevent decay around the filling.7
No filling fixes the cause. Without daily fluoride and saliva care, new decay tends to form around whatever we place.
The link to osteoradionecrosis
Unchecked decay can reach the nerve or break a tooth off at the gumline. Removing a tooth from bone that received high-dose radiation can expose bone that won’t heal, called osteoradionecrosis (ORN). The ISOO-MASCC-ASCO guideline recommends offering alternatives to extraction, such as a root canal, crown, or filling, for teeth in the high-dose area.1
If you’ve had head and neck radiation, tell every dentist who treats you, every time. Keep a copy of your radiation summary.
You’ll get the fee for each step in writing before any repair starts. Cost depends on how many teeth are involved, the material, and whether a tooth needs a crown or root canal.
Frequently asked questions
Questions about fluoride trays and radiation caries.
Where can I get fluoride trays in Jacksonville?
Dr. Henley makes custom fluoride trays at our San Marco office, 3675 Hendricks Avenue, for people before, during, and after head and neck radiation. Referred patients are typically seen within 72 hours. Call 904.398.1549, or have your oncology team use our physician referrals page.
What is radiation caries?
It’s fast-moving tooth decay that can follow radiation to the head and neck. Lost saliva is the main driver. It often starts along the gumline, on the biting edges of front teeth, or on smooth surfaces, and it can spread across many teeth in a short time if it isn’t prevented.
Why are my teeth falling apart after radiation?
Most often it’s decay at the gumline that weakens the tooth until the top breaks off. Less saliva, diet changes, and sometimes skipped fluoride all add up. Please don’t wait. Early spots can often be filled, and we can tighten up your prevention routine before more teeth are affected.
How long do I need to use fluoride trays?
If radiation left you with lasting dry mouth, daily fluoride is generally advised for life. Some people whose saliva recovers well may be able to change their routine later, but that’s a decision to make with your dentist based on your exam, not on how your mouth feels.
How long do I leave the trays in?
Use the time your dentist gives you. It’s commonly about 5 to 10 minutes. Afterward, spit out the extra gel, don’t rinse, and avoid eating or drinking for about 30 minutes. Bedtime works well for most people.
Can I just brush on the fluoride instead of using trays?
Often, yes. A prescription 5,000 ppm fluoride gel or paste brushed on daily is a reasonable option, especially if you can’t tolerate trays. Trays hold the gel against the gumline longer. Dr. Henley will help you choose what fits your mouth and your routine.
What if my mouth is too sore during radiation to use the trays?
Tell us and your radiation team. A sore mouth during treatment is common. We may suggest a gentler routine for a while, such as brushing on the gel with a soft brush, and then getting back to trays when you’re able. Don’t just stop without a plan.
My trays don’t fit anymore. What should I do?
Call us. New crowns, fillings, lost teeth, and normal shifting can change the fit, and warped trays from hot water are common too. A tray that rocks or won’t seat lets gel leak away from the gumline. New trays can be made from a fresh mold or scan.
Can radiation caries be fixed?
Often, yes, especially when it’s caught early. Small areas are usually filled with glass ionomer or composite. Larger damage may need a crown or root canal. After radiation, saving a tooth is usually preferred over pulling it because of the risk of osteoradionecrosis.
How often should I see the dentist after radiation?
More often than twice a year for most people, and closer together in the first months after treatment. Dr. Henley sets the interval based on your saliva, your decay history, and how your home routine is going.
Your next step
Protect the teeth you have now.
Whether radiation is weeks away or years behind you, it’s worth getting your teeth checked and your fluoride routine set up right. Dr. Henley is affiliated with Baptist Medical Center Jacksonville, is a member of the Baptist MD Anderson Head and Neck Tumor Board, and coordinates with your oncology team. Dental care never replaces your cancer follow-up. We’re an out-of-network dental office and don’t bill medical insurance. You’ll get the fee for each step in writing before treatment starts. More on how we work with cancer teams is on our dental care for cancer treatment page.
CJ Henley, DMD, PA3675 Hendricks Avenue
Jacksonville, FL 32207
Prefer a nonurgent text? 904.762.5616 is our practice on-call and text line. Please don’t send sensitive health information by text, and call for anything urgent.
Related pages
Sources
- Peterson DE, Koyfman SA, Yarom N, et al. Prevention and Management of Osteoradionecrosis in Patients With Head and Neck Cancer Treated With Radiation Therapy: ISOO-MASCC-ASCO Guideline. J Clin Oncol. 2024;42(16):1975-1996.
- National Institute of Dental and Craniofacial Research. Oral Complications of Cancer Treatment: What the Dental Team Can Do. National Institutes of Health.
- Brennan MT, Treister NS, Sollecito TP, et al. Dental Caries Postradiotherapy in Head and Neck Cancer. JDR Clin Trans Res. 2023;8(3):234-243.
- Kielbassa AM, Hinkelbein W, Hellwig E, Meyer-Lückel H. Radiation-related damage to dentition. Lancet Oncol. 2006;7(4):326-335.
- Silva AR, Alves FA, Antunes A, Goes MF, Lopes MA. Patterns of demineralization and dentin reactions in radiation-related caries. Caries Res. 2009;43(1):43-49.
- Frydrych AM, Slack-Smith LM, Parsons R. Compliance of post-radiation therapy head and neck cancer patients with caries preventive protocols. Aust Dent J. 2017;62(2):192-199.
- De Moor RJ, Stassen IG, van ’t Veldt Y, Torbeyns D, Hommez GM. Two-year clinical performance of glass ionomer and resin composite restorations in xerostomic head- and neck-irradiated cancer patients. Clin Oral Investig. 2011;15(1):31-38.
- Agarwal D, Purohit B, Ravi P, Priya H, Kumar V. Effectiveness of topical fluorides in prevention of radiation caries in adults: A systematic review and meta-analysis. Oral Oncol. 2022;129:105869.