Silver Diamine Fluoride (SDF) in Guelph
Silver diamine fluoride is a liquid we paint onto a cavity to stop it from getting worse. There’s no drilling and no needles. It’s especially useful for young children, anxious patients and people with health or mobility challenges.
It has one important trade-off: the decayed spot turns permanently black. This page explains how SDF works, who it suits, and when a filling is the better choice.
- SDF stops many cavities from growing. It doesn’t rebuild the tooth.
- There’s no drilling and no freezing, and each tooth takes only a minute or two.
- The decayed area turns permanently black. Healthy enamel doesn’t.
- It usually needs a second coat, then reapplication about twice a year.
- It’s approved by Health Canada and covered by the Canadian Dental Care Plan (CDCP).
What is silver diamine fluoride?
Silver diamine fluoride (SDF) is a clear-to-light-blue liquid brushed onto a cavity. The product used in Canada is a 38% solution.
Health Canada approved it in 2017 to stop existing cavities from getting worse in both baby and adult teeth. It had already been used in other countries for decades, and the World Health Organization lists it as an essential medicine for treating tooth decay.
SDF is not the same as the fluoride varnish your child gets at a check-up. Fluoride varnish helps prevent cavities. SDF treats a cavity that’s already there.
How SDF works
Each ingredient does a different job:
- Silver kills the bacteria causing the decay.
- Fluoride hardens the softened tooth surface and makes it more resistant to acid.
- Ammonia keeps the silver and fluoride stable in the liquid.
Together they stop the bacteria that are eating the tooth and harden the soft, decayed area. A cavity that has stopped (arrested) turns dark and feels hard when your dentist checks it.
Who is SDF a good option for?
- Toddlers and young children with cavities in baby teeth who aren’t ready to sit through a filling
- Children with several cavities, to stop decay quickly while fillings are planned over several visits
- Anxious patients or people with sensory sensitivities, for whom needles and drills are a real barrier
- Children and adults with special health care needs, where long appointments or sedation carry extra risk
- Baby teeth that will fall out soon, where stopping the decay may be all the tooth needs
- Older adults with decay on exposed roots or around crowns, and anyone who is frail or homebound
- People with sensitive teeth, since SDF can also reduce sensitivity on exposed roots
When SDF isn’t a good fit
- The tooth is painful, or there are signs of nerve infection or an abscess. That tooth needs other treatment.
- The cavity is very deep or large, or the tooth is breaking down.
- The patient has a silver allergy.
- There are painful ulcers or sores in the mouth, or severe gum inflammation.
- The cavity is on a front tooth and a dark spot isn’t acceptable to you. A tooth-coloured filling may suit you better, or the stain can be covered later.
SDF vs. fillings: how to choose
| Silver diamine fluoride | Tooth-coloured filling | |
|---|---|---|
| What it does | Stops the decay but doesn’t repair the hole | Removes the decay and rebuilds the tooth |
| Needles / drilling | None | Usually both |
| Time per tooth | About 1–3 minutes | About 20–45 minutes |
| Appearance | Decayed area turns black permanently | Matches the tooth |
| Follow-up | Reapplication, usually twice a year | Checked at regular visits |
| Best for | Small, painless cavities; young or anxious patients; teeth that will fall out soon | Larger or painful cavities; front teeth; long-term strength |
| Cost | Lower | Higher |
It isn’t always one or the other. We often use SDF first to stop the decay. Then we place a filling over the treated tooth when the child is older and more comfortable.
What happens at an SDF visit
- Exam and x-rays. We check how deep each cavity is and confirm the tooth isn’t infected. We go over the staining with you and ask for your written consent.
- Protect and dry. We put a little petroleum jelly on the lips and gums, keep the tooth dry with cotton rolls, and gently clear away loose debris. There’s no drilling.
- Paint it on. We use a tiny brush to apply a small drop of SDF to the cavity. We leave it for about a minute, or as long as your child can manage.
- Seal it in. We often add a layer of regular fluoride varnish on top to help keep the SDF in place.
- Done. Most children are in and out in minutes. Some notice a brief metallic taste.
About the black staining
Staining is the main reason families say no to SDF, so it helps to understand it before deciding.
- Only the decayed part of the tooth turns dark, usually within a day or two. Healthy enamel doesn’t stain.
- The dark colour is a good sign. It shows the decay has stopped.
- On back teeth it’s rarely noticeable. On front teeth it can be.
- The stain is permanent on the tooth. A tooth-coloured filling can be placed over it later, and baby teeth fall out on schedule.
- If SDF touches the skin, gums or lips, it can leave a temporary grey or brown mark that fades in one to three weeks. It permanently stains clothing, so we use a bib.
Aftercare and follow-up
The day of treatment
- Eating and drinking right away is fine unless we tell you otherwise.
- Brush as normal that night with fluoride toothpaste.
- A slight metallic taste may last a few hours.
Going forward
- Plan a re-check and a second coat, usually within a few weeks to a few months.
- After that, expect reapplication about every six months at recall visits.
- Cut back on sugary drinks and snacks between meals. SDF stops existing cavities but doesn’t prevent new ones.
Is SDF safe?
Yes. SDF is approved by Health Canada and is on the WHO essential medicines list. Pediatric dental guidelines, including those of the American Academy of Pediatric Dentistry, support using it to manage cavities in children.
The amount used is very small. A single drop can treat several teeth, and no serious side effects have been reported at dental doses. The common side effects are cosmetic: staining, a brief metallic taste, and temporary marks on the skin or gums.
Tell us before treatment about any allergies, especially to silver or other metals, and about any medical conditions or medications.
Cost and insurance coverage
- Private insurance: Many plans cover SDF under preventive or basic services, but coverage varies. We bill directly where your plan allows and can check your coverage before the visit.
- Canadian Dental Care Plan: The CDCP lists SDF as a covered service, currently limited to two treatments in 12 months. A co-payment may apply depending on your family income. We’ll confirm before treatment.
Who provides SDF at our office
Our dentists apply SDF as part of a broader cavity-management plan. That plan includes checking your child’s cavity risk, diet and brushing habits, plus fluoride varnish and sealants.
Silver diamine fluoride FAQs
Is silver diamine fluoride safe for children?
Yes. SDF has been used for decades, is approved by Health Canada as an anti-cavity agent, and is on the World Health Organization’s list of essential medicines. Only a tiny drop is used. It isn’t suitable for anyone with a silver allergy or painful mouth sores.
Does it hurt?
No. There are no needles and no drilling. Most children only notice the taste. If a tooth is already very sensitive, it may sting briefly.
Will the black stain go away?
No. The decayed part of the tooth stays dark, but healthy enamel doesn’t stain. The stain can be covered later with a tooth-coloured filling, and baby teeth with the stain fall out naturally.
Does SDF replace a filling?
Sometimes. SDF stops decay but doesn’t rebuild the tooth. For small cavities in baby teeth, it may be all that’s needed. Larger cavities, painful teeth, and front teeth where appearance matters often still need a filling, either now or later.
How many times does SDF need to be applied?
Most cavities need a second application a few weeks to months later, then a check at each recall visit. Reapplying about twice a year keeps more cavities stopped.
Can adults get SDF?
Yes. Adults get it for decay on exposed roots, decay around crowns, and sensitive teeth. It also helps patients who can’t easily have fillings.
Is SDF the same as the fluoride my child gets at cleanings?
No. Fluoride varnish at check-ups helps prevent new cavities. SDF is a stronger treatment for a cavity that has already formed.
Does the CDCP cover silver diamine fluoride?
Yes. The Canadian Dental Care Plan lists SDF as a covered service, currently limited to two treatments in 12 months. A co-payment may apply depending on your family income. We’ll confirm before treatment.
Find out if SDF is right for your child
Book an exam and we’ll go over every option, from SDF to fillings to waiting for now, so you can choose what fits your child.