Do Baby Teeth Cavities Need Filling? Each Option Explained
Clinically reviewed by Dr. Abinaash Kaur, DDS, RCDSO, on 2026-10-28. Dr. Kaur is a general dentist in Toronto (Bloor West Village) registered with the Royal College of Dental Surgeons of Ontario.
Sometimes, and the deciding factor isn't that the tooth will fall out one day. It's how big the cavity is, whether it's growing, and how many years that tooth still has to serve before the adult tooth under it is ready.
The Canadian Dental Association puts the rule plainly: a cavity that is small and seems not to progress rapidly may be monitored, while one that is bigger or shows signs of progression should be filled right away (Canadian Dental Association). The same page says a large cavity left unfilled can get bigger and cause pain, infection or tooth loss.
So the honest answer is a ladder, not a yes or no. Watching, a painted-on liquid, a filling, a silver crown, a baby root canal, or taking the tooth out: each rung fits a different tooth and a different child. Here's what each one means, what the research says, and what it costs in Ontario.
Why treat a tooth that's going to fall out anyway?
Most parents think a baby tooth with a cavity can be left alone because it's temporary. Here's what happens instead.
Baby teeth don't all leave at once. Children start losing them at around age six and keep losing them until they're about 12, according to the Canadian Dental Association (Canadian Dental Association). A back baby molar in a four-year-old may have six or more years of chewing ahead of it. A cavity doesn't wait that long.
They also have jobs. The Public Health Agency of Canada lists three: chewing, speech, and saving space for the adult teeth, which the baby teeth guide into the right spot (Public Health Agency of Canada). The same page says untreated decay can lead to pain and infection and can affect a child's sleep, learning, speaking and eating.
Pain is the part parents underestimate. A 2026 review of 20 studies found that early childhood cavities were consistently linked with poorer quality of life, with pain, trouble eating, disturbed sleep, irritability and family distress the most affected areas (Journal of Clinical Medicine review via PubMed).
Decay in small children isn't rare. Statistics Canada measured children's mouths directly in 2022 to 2024 and found 17% of children aged 1 to 5 had at least one baby tooth affected by decay, and 57% of children aged 6 to 11 had at least one affected tooth (Statistics Canada).
When can a baby-tooth cavity just be watched?
When it's small and it isn't moving. That's the CDA's own wording, and watching is a real option, not a cop-out (Canadian Dental Association).
Watching means a plan, though. The spot gets written down, brushing and sugar habits get a tune-up, fluoride goes on, and the tooth gets rechecked in a few months. The Ontario Dental Association's point is that a small cavity is easier to treat, because an untreated one grows until bacteria reach the soft inner tooth (Ontario Dental Association).
What gives a watched spot its best chance? Fluoride. A large American review of 44 trials found fluoride varnish, alone or with sealants, among the most effective ways to stop or reverse early decay that hasn't yet formed a hole (Journal of Dental Research via PubMed).
Our post on whether a cavity can heal itself explains where that line sits.
Once there's a hole, watching alone stops being enough.
What does silver diamine fluoride do, and when does it fit?
Silver diamine fluoride is a liquid a dentist paints onto a cavity to stop it growing, with no drilling and no freezing. It doesn't fill the hole, and it turns the decayed part black.
A 2024 Cochrane review of 29 trials concluded it may offer benefit over placebo or no treatment in arresting decay in baby teeth, though the certainty of that evidence was low (Cochrane review via PubMed).
The American review above was more confident on one use: 38% silver diamine fluoride applied twice a year was the most effective option for arresting advanced cavities (Journal of Dental Research via PubMed).
Where does it fit on the ladder? Between watching and drilling. It suits a young child who can't yet sit through a filling, a tooth close to falling out on its own, or a family that needs to stop things getting worse while a fuller plan comes together. Our post on silver diamine fluoride for kids' cavities covers the trial numbers and the black-stain trade-off.
When does a baby tooth need a filling, and what's the visit like?
When the cavity is bigger or it's growing. The CDA says the proper treatment then is to have it filled right away (Canadian Dental Association).
A filling on a baby tooth works the way an adult filling does. The decay gets cleaned out and the hole gets rebuilt, usually with a white material. Health Canada says that when appropriate, children's baby teeth should be filled with non-mercury materials (Health Canada). The materials themselves are covered in our filling cost guide.
What's it like for the child? Have no fear. There's usually a little pinch for the freezing, some pressure and a buzzing sound, and then it's done. Being honest about the pinch works better than promising there's nothing.
In 25 years in Bloor West Village, the first fillings that go well are the ones where the child knew what was coming and got to hold the mirror. Some days the schedule pushes me, and a nervous five-year-old still gets the slow version.
Why would a dentist put a silver crown on a baby tooth?
Because for a badly decayed back baby tooth, a crown lasts better than a filling. A Cochrane review of five trials concluded that crowns placed on decayed baby molars, or after a nerve treatment, are likely to reduce the risk of major failure or pain in the long term compared to fillings (Cochrane review via PubMed).
The crown is a preformed stainless steel cap, so yes, it's silver. Nobody loves the look on a front tooth, which is one reason these are mostly used on back teeth where the chewing load is.
Did you know about this? There's a version with no drilling at all. In the Hall technique, the crown is pushed over the tooth with no freezing, no decay removal and no tooth preparation, sealing the decay in (Cochrane review via PubMed).
The same review found less discomfort during the procedure with Hall crowns than with fillings, though a later trial that measured pain scores directly found them similar (Evidence-Based Dentistry via PubMed).
The results hold up outside the lab. In a New Zealand trial of 570 decayed baby molars, stainless steel crowns were the most successful restoration whether placed the Hall way or the conventional way, with success rates of 85% and 86% at two years (JDR Clinical and Translational Research via PubMed).
A German trial that followed children for about two and a half years found survival of 92.5% for Hall crowns, against 70.5% for a fluoride-and-watch approach and 67.2% for conventional fillings (Caries Research via PubMed).
The Canadian Dental Care Plan's own guide lists when a stainless steel crown is indicated: baby or adult teeth with extensive decay, after a pulpotomy or pulpectomy, when other materials are likely to fail, and as the definitive treatment for high-cavity-risk children (Government of Canada, CDCP guide).
What is a pulpotomy, and does it work?
A pulpotomy is the baby-tooth version of a root canal. When decay has reached the nerve, the dentist removes the infected part of the nerve inside the crown of the tooth, puts a medicated dressing on what's left, and seals the tooth, usually under a stainless steel crown.
Does it work? Pretty much, yes. A Cochrane review of 87 trials covering 7,140 treated teeth concluded that pulp treatment for extensive decay in baby teeth is generally successful, with many trials reporting no failures at all (Cochrane review via PubMed). The same review found a mineral-based dressing called MTA may be the most effective one after a pulpotomy.
Why not just pull a tooth that's reached the nerve? Because a treated tooth keeps its jobs. It chews, it holds its space, and it leaves when it's meant to. The CDCP guide names a stainless steel crown as the restoration indicated after a pulpotomy (Government of Canada, CDCP guide), so the two usually come as a pair.
When is pulling the tooth the right call, and what's a space maintainer?
When the tooth can't be saved. An abscess that keeps coming back, a tooth with too little left to hold a crown, or a tooth a few months from falling out anyway are the usual reasons. The CDA's own list of what a large unfilled cavity leads to ends with tooth loss (Canadian Dental Association).
The catch is the space. The Public Health Agency of Canada explains that without a baby tooth as a guide, adult teeth can shift into the gap, leading to crowding and bite problems (Public Health Agency of Canada). A space maintainer is a small metal band-and-wire holder that keeps the gap open until the adult tooth arrives.
Does every pulled baby molar need one? No.
A 2023 meta-analysis of 11 studies in children aged 5 to 10 measured the gap after a first baby molar is lost early: about 0.65 mm of space was lost in the upper jaw and 1.24 mm in the lower jaw over 6 to 24 months, with no change in overall arch width or length (BMC Oral Health via PubMed).
An earlier University of Alberta review judged a similar amount not likely to be of clinical significance in most cases, while noting it could matter in a child already short on room (Pediatric Dentistry via PubMed).
So a space maintainer is a judgment call about which tooth, which age, and how crowded the mouth already is. Our extraction cost guide covers what the removal itself involves.
What do these cost in Toronto, and what do CDCP or Healthy Smiles cover?
The fee depends on which rung of the ladder, how many surfaces of the tooth are involved, whether X-rays or sedation are added, and whether a crown follows. Rather than invent numbers, here are the ones already published.
Our 2026 Toronto price roundup lists a complete exam at $96 for baby teeth from the Ontario Dental Association fee guide, as publicly reported. The filling cost guide lists a one-surface white filling on an adult tooth at about $214 to $257, and the extraction guide lists a simple extraction at $218. Those are guide ballparks, not quotes.
The clearest public figures for baby teeth are in the Canadian Dental Care Plan's 2026 Ontario fee grid, general dentist column (Sun Life, 2026 Ontario CDCP grid). Its composite fillings on baby teeth block runs from $169.18 to $235.06, every prefabricated crown code is listed at $235.06, the pulpotomy block starts at $141.57, and an uncomplicated extraction is $180.75.
Those are what the plan pays, not what any office has to charge.
For CDCP families, the plan covers permanent fillings and pulpectomies without preauthorization, while crowns and deep sedation or general anesthesia need approval first (Government of Canada, CDCP coverage). Your share depends on adjusted family net income: nothing under $70,000, 40% from $70,000 to $79,999, and 60% from $80,000 to $89,999.
Two rules in the plan's guide matter for little ones: fillings on baby front teeth are covered only for children under five, and each tooth surface is covered once in any 24 months (Government of Canada, CDCP guide).
Healthy Smiles Ontario is free for eligible kids 17 and under, and it covers fillings, extractions, and urgent care for a child's toothache (Government of Ontario). As of July 1, 2026, a family with one child qualifies at a net income of $29,065 or lower, and the line rises by $2,200 for each additional child.
The program's service list notes some age restrictions on permanent fillings for baby teeth and covers sedation from 15 minutes to 2.5 hours per year (Government of Ontario). Our CDCP and Healthy Smiles comparison walks through which plan to apply for first.
Frequently Asked Questions
Q: My child fell and now a front baby tooth has turned grey. Is it dead? Not always, but it needs a look. In a study of 727 injured baby front teeth, 23.8% went on to lose their nerve, and grey, yellow or brown discolouration was one of the factors linked with that outcome, along with pain and injuries that moved the tooth (International Journal of Paediatric Dentistry via PubMed). A grey tooth with no pain, no swelling and no bump on the gum is often watched; one with an infection is treated or removed.
Q: There's a pimple on the gum above a baby tooth. What is it? Usually a draining abscess from a tooth whose nerve has died, and it means the infection is finding its way out. Statistics Canada found 7% of children and youth aged 1 to 19 had an advanced consequence of untreated decay, such as an abscess or a draining infection, in 2022 to 2024 (Statistics Canada). It won't fix itself, so book a visit; our emergency dentist guide covers what counts as urgent.
Q: Will my child need to be put to sleep for this? Most fillings on cooperative children happen awake, with freezing. The CDA's position is that a child's developmental level and the extent of disease decide whether behaviour guidance, sedation or general anesthesia is needed (Canadian Dental Association). Our sedation options guide explains the levels.
Q: Can I just wait for the tooth to fall out? Only if it's close to falling out on its own and the cavity is small and still. Children lose baby teeth from about age six until about 12 (Canadian Dental Association), so a back molar in a young child has years to go, and the CDA says a bigger or progressing cavity should be filled right away (Canadian Dental Association).
Q: How do I stop the next cavity? Fluoride toothpaste twice a day with a parent doing the brushing, water in the bedtime bottle, and an early first visit. The CDA encourages a first dental assessment within six months of the first tooth and no later than 12 months of age (Canadian Dental Association). Our posts on fluoride and Toronto's water, sealants for the first adult molars, and the first tooth to the first visit cover the rest.
Reviewed by Dr. Abinaash Kaur, B.Sc., DDS (University of Toronto Faculty of Dentistry), who has practised general and family dentistry in Bloor West Village for about 25 years. This article is general oral health information, not a diagnosis or a substitute for an examination of your child.
Found a spot on your child's tooth, or been told they need a filling and want to understand the options first? Bring them in and we'll look, show you what we see, and go through the ladder together, one rung at a time. We're at 750 Annette Street in Bloor West Village, serving the Junction, High Park, and Baby Point. Book a visit with The Village Dentist and we'll make a plan that fits your child.
