If you’ve noticed something unusual on your tooth – a dark spot, a rough patch, or a small hole – you’re probably asking yourself, ‘What does a cavity look like?’ You’re in the right place. Cavities are one of the most common dental problems in Australia, but many people miss them simply because they don’t know what early signs to look for.
The good news: the earlier you catch a cavity, the easier it is to treat. At Smile By Design , with clinics in Bondi and North Sydney , we see patients every day who have either spotted an issue themselves or who come in for a routine check-up and find a cavity they had no idea was there.
This guide explains what a dental cavity looks like at every stage, what the warning signs are, and when it’s time to see a dentist.
What Is a Cavity?
A cavity, medically known as ‘dental caries’, is a permanently damaged area in the hard surface of a tooth. It happens when bacteria in your mouth feed on sugars and produce acids that gradually erode the tooth enamel. Left untreated, this erosion deepens, eventually reaching the sensitive inner layers of the tooth.
Cavities don’t fix themselves. Unlike a skin cut that heals, once tooth enamel is lost, it doesn’t grow back. This is why the beginning of tooth decay is the most important stage to catch because that’s where it can be stopped with the least intervention.
Our team at Smile By Design recommends a check-up every six months to catch cavities early, often before they cause any symptoms at all.
What Does a Cavity Look Like? From Early to Advanced
What a dental cavity looks like depends entirely on how far the decay has progressed. Here’s what you might see at each stage:
Stage 1 – White or Chalky Spot (Early Cavity Sign)
The first sign of a cavity is often barely noticeable: a small white, chalky, or opaque patch on the enamel surface. This is called demineralisation, where the enamel begins losing minerals but hasn’t yet broken down. At this stage, it’s sometimes possible to remineralise the tooth with fluoride, making it the only stage where a cavity can potentially reverse itself.
Stage 2 – Yellow or Brown Discolouration
As decay progresses, the affected area darkens to yellow, light brown, or dark brown. This is what most people picture when they think of what a cavity looks like. The enamel has now broken down, and decay is spreading into the dentine layer beneath. A tooth-coloured filling is the standard treatment at this stage.
Stage 3 – Visible Hole or Pit in the Tooth
A more advanced cavity creates a visible hole, pit, or crater in the tooth – this is what many patients describe as a “hole in my tooth”. You may be able to see it or feel it with your tongue. At this stage, decay may have reached the pulp (the nerve), causing significant pain, sensitivity, or even abscess. Treatment typically involves a root canal or a dental crown.
Stages of Tooth Decay at a Glance
| Stage | What’s Happening | Looks Like | Treatment Needed |
| Stage1 | Enamel losing minerals | White/chalky spot on surface | Fluoride treatment + improved hygiene (may reverse) |
| Stage2 | Enamel breaking down | Yellow or brown discolouration | Tooth-coloured filling |
| Stage3 | Decay reaches the dentine. | Dark pit, visible hole, sensitivity | Filling or dental inlay |
| Stage4 | Pulp / nerve affected | Visible hole, significant pain | Root canal + crown |
| Stage5 | Abscess / infection spread | Severe pain, swelling, very dark tooth | Extraction or root canal — urgent |
Stages 1–2 are where we want to catch and treat decay. Stages 4–5 require urgent treatment.
Spotted something on your tooth?
Book a check-up at Smile By Design Bondi or North Sydney
What Does a Hole in a Tooth Look Like?
A hole in a tooth is one of the most recognisable signs of advanced decay. Here’s how it typically presents:
- A small dark dot or indent on the chewing surface of a molar
- A visible crater or pit that you can see or feel with your tongue
- A rough or jagged edge where the enamel has broken away
- A dark gap or shadow between teeth a sign of interproximal (between-tooth) decay
Important: not all holes in teeth are visible to the naked eye. Many form between teeth or just below the gumline where only a dental X-ray can detect them. This is why relying on what you can see at home isn’t enough.
What Does Tooth Decay Look Like on Different Teeth?
Where the cavity forms affects how it looks. Here’s a quick reference for what tooth decay looks like in different parts of the mouth:
| Tooth / Location | What Decay Looks Like | Key Warning Sign |
| Front teeth | White/brown spot or dark line between teeth | Gap or shadow between teeth; chip on edge |
| Molars (back teeth) | Dark brown/black pit in the grooves | Visible hole or rough crater on chewing surface |
| Between all teeth | Not visible — shadow on X-ray only | Floss shredding; dull ache in that area |
| Near the gumline | Yellow/brown discolouration along the gum | Sensitivity when cold liquid touches gumline |
| Black cavity | Very dark brown or black area on enamel | Sign of long-standing or advanced decay |
A cavity on a molar is one of the most common types because the deep grooves of back teeth trap food and bacteria. A smooth surface cavity (on the flat sides of teeth) typically forms where two teeth contact each other and where a toothbrush can’t reach.
Signs of a Cavity You Can Feel – Not Just See
Not all cavities announce themselves visually. These are the physical warning signs to pay attention to:
5 Symptoms of a Cavity
- Sensitivity to hot, cold, or sweet – a sharp, brief sting when eating or drinking
- Spontaneous toothache – unprovoked aching or throbbing pain in a tooth
- Pain when biting – discomfort when pressure is applied to a specific tooth
- Persistent bad breath – bacteria in a decaying cavity produce a distinct odour
- Rough or uneven texture – a new feeling when running your tongue across a tooth
One important caveat: many cavities have no symptoms at all in the early stages. Pain tends to appear only once decay has reached the deeper dentine layer, by which point the cavity is well-established. Waiting for pain to appear is not a reliable strategy for protecting your teeth.
How to Tell If You Have a Cavity
Wondering how to know if you have a cavity? Here are the practical steps:
- Check in a mirror with a torch – look for dark spots, white chalky patches, visible holes, or discolouration
- Run your tongue across each tooth – feel for rough patches, pits, or uneven surfaces
- Note any pain or sensitivity – even mild aches when eating cold or sweet foods are worth investigating
- See a dentist for an X-ray – the only reliable way to find cavities between teeth or below the gumline
The honest truth: you often can’t tell on your own, especially for early dental cavities. A professional examination is the only definitive way to know whether you have one and how far it has progressed.
How a Cavity Affects Your Smile
Beyond the structural damage to your tooth, cavities can have a visible impact on your smile:
- Visible staining – dark spots and brown patches on teeth are immediately noticeable
- Holes or pits – visible damage changes the shape and texture of your teeth
- Tooth loss – severe untreated decay can lead to extraction, leaving a gap in your smile
- Bad breath – active decay creates bacterial activity that brushing alone won’t fix
- Loss of confidence – many patients tell us they stopped smiling openly because of visible decay
The good news is that most decay-related damage is restorable. A well-placed tooth-coloured filling can make the tooth look completely natural again. For more extensive damage, dental crowns or veneers can restore the appearance of your smile once the underlying decay has been treated.
Want to restore your smile after decay?
Talk to our team at Smile By Design — Bondi or North Sydney
Cavity Treatment at Smile By Design – Bondi & North Sydney
At Smile By Design, we treat cavities at every stage across both our Bondi and North Sydney clinics. Our approach is to match treatment to the exact stage of decay – no over-treatment, no under-treatment.
- Dental check-up & X-ray – to find cavities before they cause pain or visible damage
- Tooth-coloured fillings – the standard treatment for early-to-moderate cavities; virtually invisible
- Root canal treatment – when decay has reached the tooth’s nerve or pulp
- Dental crowns – to restore teeth that have been significantly weakened by decay
- Cosmetic restoration – for teeth with visible discolouration or damage from past decay
Frequently Asked Questions
1. What does a cavity look like on a front tooth?
On front teeth, a cavity usually starts as a white chalky spot, progressing to a brown or yellow patch. Between front teeth, you may notice a dark shadow or staining along the contact point. Advanced decay creates a visible pit or chip.
2. What does dental decay look like on a molar?
A cavity on a molar typically appears as a dark brown or black pit in the grooves of the chewing surface. Because molars sit at the back, they’re hard to see which is why decay often goes unnoticed until a check-up or X-ray reveals it.
3. What does a hole in a tooth look like?
A hole in a tooth usually looks like a dark indent, crater, or broken edge on the tooth surface. You may be able to feel it with your tongue before you can see it. If you feel a rough or pitted area on any tooth, book an appointment.
4. Can a cavity look like a white spot?
Yes and this is actually the earliest visible sign of a cavity. White or chalky spots indicate demineralisation, where the enamel is losing minerals. At this very early stage, the process may still be reversible with fluoride. It’s worth getting it checked immediately.
5. How do you know if you have a cavity between teeth?
Interproximal cavities (between teeth) are almost always invisible to the naked eye. You might notice floss catching or shredding in a specific spot, or feel a mild ache. Only a dental X-ray at a check-up can confirm them another reason six-monthly visits matter.
6. Do cavities always cause pain?
No. Many cavities cause no pain at all in the early stages. Pain only appears when decay reaches deeper layers of the tooth. By that point, a simple filling may no longer be sufficient. Don’t wait for pain — get regular check-ups to catch cavities silently.
7. How often should I get checked for cavities in Bondi or North Sydney?
Our team at Smile By Design Bondi and North Sydney recommends a check-up every six months. This allows us to detect cavities in their earliest stages, take X-rays when needed, and keep your teeth clean with a professional scale and clean.
Spotted a Cavity? Don’t Wait.
The earlier you treat a cavity, the simpler and less costly the treatment.
Book a check-up at Smile By Design today.
