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"it's pretty obvious that removing rotting food from your gums is good and leaving it there to putrefy is bad, don't you think?"

But is that actually true? Has anyone actually confirmed it with replicable scientific studies? Did early human teeth rot to hell over the first 10 years of their lives? Why don't cats and monkeys need to brush and floss?

"please use your common sense"

The problem with common sense is that it can be deceptively nonsensical, and we tend to ignore that we haven't proven it because we "know" it's true already.

Pets, cats, and dogs only live until they're 20. AND pets DO have lots of problems with dental health. What is with all these people questioning flossing here? Floss your damn teeth. Worst that can happen is the poor guy you work with doesn't have to smell the decomposing food coming out of your mouth. JFC

We’ve changed pet food just like we’ve changed our own food. Notice how pets and animals that eat human food (like raccoons) are all getting fat together.

Looking at modern dog dental hygiene to learn about how wild animals’ teeth work is as silly as looking at our dental hygiene to see how a hunter gatherer’s teeth work.

Our vet told us to brush our dog's teeth.

Works best with meat-flavored toothpaste.

Did your vet recommend to floss your dog's teeth?

I'm a veterinarian. Some cats get lucky but the majority of them deal with tooth resorption which is caused by gingivitis. This disease is found on tigers, jaguars, fossilized saber tooth tiger teeth, etc. It's painful and leads to loss of teeth. Often also leads to loss of function, i.e., reduced chewing. It's probably a leading cause of old wild cats throwing in the towel and becoming carrion.

Yep. My cat had a mouth full of rotten teeth. After removing nearly all his teeth his entire disposition changed—went from just sitting around all day to a ball of energy. It also changed his digestion: went from runny poop everywhere to Tootsie rolls.

Hunter gatherers typically had much better teeth than modern humans, although outliers do exist. The general explanation for this is that diet and nutrition have a much larger impact than mechanical cleaning do.

Recently I had a bad cavity (back of mouth, didn't hurt until gigantic, don't go to dentist regularly) and very minor bone loss in my jaw next to it. In the process, a dental hygienist explained that the primary purpose of flossing or waterpicking is to prevent bone loss in the jaw which can lead to infection and tooth loss if left untreated.

Thanks to waterpicking, the gums in that area of the jaw have healed and I shouldn't experience any more bone loss as long as I waterpick or floss.

Doesn't empirically demonstrating the efficacy of flossing face all the same challenges as any other medical research?

Of course it is difficult to definitely prove whether or not vitamin C supplements reduce the duration of a cold. That doesn't mean that we should all just abandon empiricism and start gulping vitamins because it is "common sense."

What if someone's "common sense" leads them to believe that use of a an abrasive cleaning technique like flossing might damage their gums? I can think of any number of non-scientifically backed rationalizations one could use for or against flossing.

So, even if not-definitive, what research is there on whether flossing improves oral or overall health?

What I meant with that "common sense" sentence was basically this:

- It's irrelevant to know if flossing "improves" overall health...what is relevant is that it will not worsen it, and you are removing rotting stuff from your teeth, and worst case scenario you just waste 2-3 minutes and have a more pleasant breath..why overcomplicate things?

It doesn't worsen your health, it either does nothing or improve it, so it is reasonable to do it

Medical literature is full of these things: do you need people to prove it with several studies that it's good for you to go for a walk every day? Try to weight the cost-benefit of your actions...if the cost is small, the risk non-existant, and the potential benefit high, it's usually a good idea

> It doesn't worsen your health, it either does nothing or improve it, so it is reasonable to do it

There are thousands of wives tales and pseudoscience remedies I don't need to waste my time on. If not backed by actual science, this type of recommendation is no better than any of them.

Here's the latest info I found on PubMed: https://www.ncbi.nlm.nih.gov/pubmed/30968949 - "Home use of interdental cleaning devices, in addition to toothbrushing, for preventing and controlling periodontal diseases and dental caries." As dental plaque is the primary cause [of tooth decay and gum disease], self-administered daily mechanical disruption and removal of plaque is important for oral health. Toothbrushing can remove supragingival plaque on the facial and lingual/palatal surfaces, but special devices (such as floss, brushes, sticks, and irrigators) are often recommended to reach into the interdental area... Using floss or interdental brushes in addition to toothbrushing may reduce gingivitis or plaque, or both, more than toothbrushing alone. Interdental brushes may be more effective than floss. Available evidence for tooth cleaning sticks and oral irrigators is limited and inconsistent. Outcomes were mostly measured in the short term and participants in most studies had a low level of baseline gingival inflammation. Overall, the evidence was low to very low-certainty, and the effect sizes observed may not be clinically important. Future trials should report participant periodontal status according to the new periodontal diseases classification, and last long enough to measure interproximal caries and periodontitis.

Basically, good current dental hygiene practice is to brush and floss like the experts tell you.

Interesting. I wonder why there aren't better studies on this, particularly when flossing is so widely recommended.

> a powered toothbrush is better simply because it does more iterations per minute than a manual one...again, common sense

It wasn't obvious to me that that would be true. Most cleaning tools aren't vibrating brushes.

I was actually concerned about damaging the teeth. You are effectively putting a power tool in your mouth.

1. What do you think about charcoal tooth pastes? I've been using this[1] and it got rid of my persistent "plaque wall" on lower incisors within ~month. I don't feel this particular one is really abrasive, but I was wondering will there be some damage to enamel with persistent use? Should I maybe alternate it with normal fluoride paste?

2. I've heard that brushing teeth before sleeping, regardless of food consumption, is great because of reduced saliva during rest means reduced anti-bacterial effects of it. Any truth in that?

3. Last dentist appointment I got mentioned that my tooth will literally explode if I don't remove it. I've read there been odd cases of that happening in history, but is there realistic chance of that happening? How would that even come to pass?

[1] https://www.splatoralcare.uk/products/biomed-charcoal-toothp...

P.S. Thanks for doing AMA. I've had nothing but horrible experience talking with dentists, or even bad experiences in general.

The exploding tooth thing is true, caused by gases released by the decay building up pressure, can be very very painful: https://en.wikipedia.org/wiki/Barodontalgia#Barotrauma

I will ask you anything then! Please tell me why I have to be sedated for everything. No amount of anesthetic ever works on me. Drilling always feels like a horrifying electric shock. And every time they touch my fillings with a metal probe, I get shocked too.

I’m not afraid of needles. I’ve had plenty of uncomfortable medical procedures. I can tolerate all other kinds of pain. But why doesn’t local anesthetic work on me for dentistry?

Do you have red hair?

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1362956/

That article is about a different process, inhalation anesthetic, rather than local (nerve-blocking,depolarizing) anesthetic.

TBH I have never had a patient on which anesthesia didn't work...the only case that's fairly common is if you have an acute infection on that tooth, in which case the effectiveness of anesthesia is greatly reduced

Lower molars receive 2-3 different innervations and it is sometimes hard for a dentist to get all of them numb

I'll say that some dentists are good at nerve blocks and others are not. Bupivacaine takes time to work and some dentists don't allow it to take its proper time. But if you have a local anesthetic properly infiltrating the nerve, and given the time to work, you will have no sensation.

You could have a sodium channel mutation (such as SCN9A) that makes you highly pain tolerant, but lidocaine-resistant[0].

It's a known syndrome, and may be associated with ADHD symptoms, episodes of intense skin flushing or redness (erythromelalgia) and epilepsy.

0. https://www.healthbusinessgroup.com/2008/01/11/what-causes-a...

Other medical sources:

  https://www.ncbi.nlm.nih.gov/books/NBK1163/
  https://www.ncbi.nlm.nih.gov/books/NBK481553/

Thank you so much. yes on the ADAH, no the skin flushing. Really appreciate your help.

My dentist gave me two options for removing my wisdom teeth a few years ago, 1: go to a dental surgeon and be put under, 2: have some kind of anesthesia but not be "asleep". I chose #2. It was some sort of concoction that, if I remember correctly, was only meant to stop me from remembering the pain/experience.

I don't have the paperwork but I've always been curious what is was that he gave me/if it was common practice. Also, if it was purely a sort of amnesia, was I in excruciating pain during the time?

I have since moved away and not been back to a dentist. If it is common, I can only imagine the stupid things I would have said or done during the procedure since during the onset I remember being extremely high. It kind of made me embarrassed to return the couple of times I did only because I don't remember what I could have done.

Does eating green vegetables, salad, herbs (I love chewing some wild thyme in the countryside) help significantly the teeth health?

Also I don't rinse after brushing my teeth, to keep the toothpaste in place so it acts as protection all the night, is it useful too?

Cavities are caused by sugars (and sugars only), so in theory, if you just eat green vegetables and meat, you shouldn't get any cavities. Veggies contain fibers and the consensus is that they exert a light brushing action on teeth (think when you chew celery and such)

A great resource for these questions is nutritionfacts.org (free and full of references to scientific studies)

As for toothpaste, what you do is ok, the only risk you run is to overdose on systemic fluoride, which sometimes causes diarrhoea. An alternative is to rinse with a mouthwash and not rinsing with water afterwards

What you're saying makes sense.

On the other hand, what are your thoughts about the relation between the type of foods we eat and dental health?

My understanding is that sugar, and (complex?) carbs in general have a massive toll on teeth. Admittedly I'm no expert, but it would seem that eating the food we evolved to eat (vegetables and meat mainly) should not damage our teeth in a significant and therefore would be no need for dental health practices.

Whether or not that is feasible on a population level is another question, but I'm fairly convinced at this point that the garbage food is wrecking our health and that includes teeth.

Actually inflammatory diets like diets high in animal protein seem to pose more of a risk to dental health than diets rich in healthy, complex carbs:

https://nutritionfacts.org/2013/07/25/do-vegans-get-more-cav...

Are there any long term health risks due to the material used in dental fillings? Any changes over the last 10-20 years? I’m thinking cancer associations, etc.

What's your opinion of Zirconium tooth replacements, as done by BioImplant (www.bioimplant.at)?

From my not-a-dentist :) perspective, the concept sounds workable.

eg creation of the 3D model from scans, using a CNC machine to create the object from Zirconium, etc.

But I've no idea what other parts would need evaluating to make real sense of it. :)

It's a cool idea and I'm pretty sure it will be more common in the future, but right now almost nobody uses it for a couple of reasons:

1- You actually need a CAT scan of the tooth you want to replace beforehand..sometimes it's not possible (i.e. people who lost their teeth years ago, and now want to replace them)

2- Costs are probably significantly higher for everyone

3- Normal implants are more versatile, as they are basically hollow screws where you can mount a second screw shaped however you want (a tooth abutment, an attachment, etc) so they are also used to stabilize dentures, to create full mouth reconstructions such as all-on-four etc..this is not possible with these zirconia implants

Is the science on xylitol still up in the air? Is it likely that it's at least as harmless (compared to sugar) as other sugar alcohols (erythritol, sorbitol, etc)?

I stopped using a powered toothbrush because:

1. my hygienist said it made no difference in plaque formation on my teeth (I did A-B experiments)

2. I was concerned it was abrading the enamel.

I'm old, btw, and am mostly concerned about receding gums and bone loss. I brush, floss, use the pipe cleaners for between teeth, and run one of those pointy rubber things along the gum line, and still get gingivitis. My dentist says there's nothing more I can do about it.

I've also tried various mouthwashes, which made no difference.

Anything else I can try?

Have you tried SmartMouth "DDS strength" mouthwash and toothpaste by chance? It contains a zinc formulation that inhibits baterial growth. So far, it's the best I've come across.

I did try a prescription-only DDS mouthwash. No difference.

> I was concerned it was abrading the enamel.

Teeth are pretty hard on the Moh's scale relative to bristles. If you're abrading enamel, it's from something in the toothpaste (which has all kinds of mineral abrasives), or tooth-tooth contact from chewing/grinding.

1. the powered ones do more "swipes" per minute, so in general they tend to be more effective. If you're good with a manual brush, you will most likely get the same results

2. enamel is far too strong to be abraded by the brush, what does get abraded is the dentin (the yellowish part closer to your gums, that's why sometimes you can see small dent-like abrasions there) so try to focus on brushing softly in those areas. A good idea is to use soft bristles

All you do is good and you're probably already doing 95% of what can be done, the other risk factors are smoking, female hormones, stress and diet. If you are not stressed, don't smoke, are male and eat mostly plant-based whole foods you can't do much more than that

Can you point to the research on the “mostly plant-based” part?

https://nutritionfacts.org/video/how-to-treat-periodontitis-...

https://nutritionfacts.org/video/best-food-for-periodontal-d...

https://nutritionfacts.org/video/plant-based-diets-dental-he...

Click on "sources cited" to find plenty of research

Greger's site. About what I was expecting...

This has to be weighed against anecdotal evidence ( good anecdotal evidence is IMO better than your average study/research) from vegans. Vegans tend to have very high occurrence of cavities despite the best of oral hygiene. ( source ex-vegans on their blogs etc.) Eskimos when first discovered by western explorers had a complete absence of cavities despite bad oral hygiene and a diet of almost no plants (Source: A book written by an explorer, whose name I cannot remember)

> I brush, floss, use the pipe cleaners for between teeth, and run one of those pointy rubber things along the gum line, and still get gingivitis. My dentist says there's nothing more I can do about it.

I am not a dentist but have similar issues:

Consider wearing a mouthguard at night? Grinding teeth during sleep can contribute hugely to bone loss.

Also make sure you're using the rubbertip correctly. It's supposed to massage the gum with the flat part, not poke with the pointy part.

You could try a dental probiotic. I got slightly better gum gap scores when I was using this one, though I stopped because I thought it was upsetting my stomach a bit. Probably going to try it again after that recent research on gingivitis and Alzheimer's. http://www.biogaia-prodentis.com/dental-professionals/