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Eight Cavities, Then None
Eight cavities from one dentist and none from another is a real story, told more than once. When a second opinion is worth getting, and when it is not.
The story that makes this subject worth writing about gets told repeatedly, by different people, with the same shape:
Get a second opinion. After years of no cavities I went to a highly recommended new dentist who told me I had 8 cavities he was going to fill. I was in shock and went to a different dentist for a second opinion and he found 0 cavi r/askdentists
Eight and then none. From two licensed professionals looking at the same mouth.
And someone who made it a policy:
I now ALWAYS get a second opinion about any dental work. I’ve done it several times now and every time the second opinion came back with no work needed. Crazyness. r/LifeProTips
And the version where it didn’t happen, which is the one that hurts to read:
Wish I had the wisdom to get a second opinion when new dentist told me 9 cavities. Destroyed my teeth completely. :( Definitely second opinion! These teeth are for life, and the repairs don’t last that long! r/askdentists
That last clause is the crux of the whole thing. The repairs don’t last as long as the tooth would have.
Why two honest dentists can disagree
It’s tempting to read every one of these as fraud, and that’s not quite right — which matters, because the wrong model leads to the wrong response.
Early decay is a genuine judgment call. A lesion in the outer enamel that hasn’t reached dentin can be filled now, or monitored and given a chance to remineralize. Both are defensible. Two clinicians can look at the same X-ray and land differently, and neither is lying.
What shifts the balance is everything around the decision: how the practice is paid, whether targets exist, how busy the schedule is, and how much time there is to explain a wait-and-see plan versus simply booking the work.
None of that is visible from the chair. Which is exactly why a second look is cheap insurance rather than an accusation.
But a filling is not a repair that ends there
This is the part that makes the stakes asymmetric, and almost nobody explains it.
Filling a tooth means removing tooth structure to place the material. The filling then has a lifespan — years, not decades — and when it’s replaced, the cavity is prepared again and a little more tooth goes. Replace it enough times and the sequence ends at a crown, then a root canal, then an extraction.
A tooth that never gets filled never enters that sequence. Which means an unnecessary filling isn’t a wasted appointment — it’s the first step on a path the tooth would otherwise not have been on.
That’s the asymmetry: watching and being wrong costs you a filling six months later. Filling and being wrong costs you the tooth’s whole future.
When it’s genuinely worth doing
Multiple cavities found at a first visit with a new dentist. This exact pattern appears in almost every one of these stories. A jump from a stable history to a long list of work is the single strongest reason to look again.
Anything irreversible. Extractions, crowns, root canals, veneers. Enamel and tooth structure do not grow back, and no amount of regret restores them.
Full-mouth treatment plans, particularly ones presented with financing attached.
Anything for a child, where the tooth may be shed anyway:
I would definately seek a second opinion and maybe even a 3rd before agreeing to that treatment for a small child. Do you have a dentist you trust and see yourself who will do a second opinion? r/Mommit
And whenever you simply don’t believe it:
If you doubt your dentist then get a second opinion/new exam from a different dentist. r/askdentists
When it isn’t
There’s a sensible counterweight in these threads, and it deserves equal weight:
LPT: don’t go to a Groupon dentist or you will get Groupon scammed. You don’t need a second opinion for things like a cavity if you are going to a trustworthy, established dentist. r/LifeProTips
A single small filling from a dentist you’ve seen for a decade is not worth a second appointment. Neither is emergency treatment for something that hurts. Delay has its own costs, and treating every recommendation as suspect is its own kind of expensive.
Do it properly or don’t bother
One reply cuts through most of the bad advice on this:
I think you’re confused. Wisdom teeth extraction is typically preventative, it isn’t an immediate problem. If your second opinion didn’t take x-rays, probably not a valid opinion. r/LifeProTips
No X-rays, no opinion. Decay between teeth and beneath existing fillings cannot be seen by looking into a mouth. A reassuring visual exam is worth nothing against an X-ray finding, and people leave relieved on exactly that basis.
So: your X-rays belong to you. Ask for copies. You do not have to explain why, and the request is completely routine.
Book a new-patient exam rather than announcing a second opinion. You’ll get a full independent assessment instead of a review of somebody else’s.
Don’t lead with the first diagnosis. Say what brought you in, not what you were told. Anchoring changes what people see.
Ask which surfaces and which teeth, and ask what happens if it waits six months. The answer to that second question tells you a great deal about how urgent the first one really was.
The tone worth having about it
There’s real anger in some of these threads, and it’s understandable:
I fucking hate the dentist so many of them are scams I get a second opinion for everything after learning the lesson the hard way with my own teeth because my parents DID NOT get second opinions. r/toddlers
The measured version is the more useful one:
You could try a second opinion if you haven’t already. I know I have heard stories where one dentist says one thing and when the person got a second opinion things weren’t as bad r/askdentists
A second opinion isn’t a verdict on anybody’s honesty. It’s what you do before spending money on something you can’t undo, in every other part of life, without it being personal.
The short version
Ask for a second look when the work is big, permanent, or arrives as a surprise from somebody new.
Bring the X-rays, book it as a fresh exam, and don’t say what you were told.
And remember which way the error runs: waiting and being wrong costs a filling, filling and being wrong costs the tooth a future it wasn’t going to need to spend.
Questions people actually ask
Should you get a second opinion on dental work?
For anything large, irreversible or expensive — multiple fillings found at a first visit, crowns, extractions, implants, full-mouth plans — yes. For a single cavity from a dentist you've seen for years, it's rarely worth the trouble.
Why do two dentists disagree about how many cavities you have?
Partly because early decay genuinely is a judgment call about whether to fill now or watch, and partly because incentives differ between practices. Both explanations are real and they're hard to tell apart from the chair.
How do you get a second opinion without offending your dentist?
You don't need permission, and you don't need to explain. Ask for copies of your X-rays — they're your records — and book a new-patient exam elsewhere. A dentist confident in their diagnosis is not troubled by this.
Is a second opinion valid without X-rays?
No. Decay between teeth and under existing fillings isn't visible by looking, so an opinion given without images isn't comparable to one given with them. Bring the X-rays or have new ones taken.