Chapter 1: Oral hygiene is confusing
Hi, I’m Wendy Zukerman and you’re listening to Science Vs from Gimlet. This is the show that pits facts against flossing, and brushing and all that crap the dentist tells you to do. How much of that is crap?
So several years ago headlines started screaming that we shouldn't be so trusting of our dentists. Particularly when it comes to flossing….. One Headline read “Dentists Say You Need to Floss. Science Says You Don't.”[1] People were pissed.
<<Dental news! >>
<<This week the AP reports that officials have never researched the effectiveness of regular flossing before cajoling all of us to do it!
I floss for a solid week everytime I go back from the dentist, cos I feel guilty! and it really serves no purpose! >
And get this – some surveys have found most dentists don't even floss every day, [2][3][4][5] With flossing in the doghouse... it made us, here at Science VS, wonder how much can we trust anything that the dentist tells us. Does brushing even matter? And what about the stuff they tell you not to eat and drink? Like there's been this rampage against seltzer for years.[6]
<<Not to burst your bubbles but is sparkling water safe for your smile?
<<People are literally sipping on through the entire day, and as they’re doing that, they’re constantly bathing their teeth in acid. …And it is almost as acidic as battery acid.>>[7]
Battery acid? Maybe that should be the new la croix flavour, am I right? So today on the show: we’re giving the dentist a drilling and finding out what you really need to do for healthy teeth. And I'm telling you.. trust no one… nothing is as it seems…
When it comes to the dentist a lot us just do stuff
<<Cos I feel guilty. Yes >>
But then there’s science.
Science Vs the dentist is coming up.
<<PREROLL BREAK>>
Chapter 2: Do flossing and tooth brushing prevent cavities?
WZ Welcome back. Today we’re looking at how much we can trust our dentists. Whether they’re just a bit long in the tooth. Senior producer Meryl Horn has been sinking her teeth into the research.
MH Is that, that’s not a thing right?
WZ That’s totally a thing you can sink your teeth into research. Arrr
MH no but the long in the tooth- that doesn’t mean lying.
WZ the long in the tooth, absolutely true. I think its about horses. It’s a horse thing. We did ketamine a few weeks ago. Couldn’t use the pun here but i found a way to bring it in here.
WZ: Why did you wanna look into this?
MH Because I want to take care of my teeth! And my kid’s teeth, like cavities are super common. Those are the little holes you can get in your teeth[8][9]
WZ yeah right
MH And I know a lot of people lose their teeth as they get older. like - 1 in 6 people who are over 65 don’t have any teeth at all.[10][11]
WZ oh wow. 1 in 6 ok.
MH Yeah- yeah in the US. And besides all that - if there are things we don’t need to be doing - stuff that actually doesn’t work - I want to know that too so I don’t waste my time!
WZ Yeah yeah if i don't need to floss, or feel guilty about not flossing, that would be great. Where do we jump in?
MH Let’s start with the basics here - brushing and flossing. And find out whether doing that stuff actually prevents cavities.
WZ look if brushing doesn’t work, that will be … I’ll be shocked, I’ll be shocked…
MH We’re not going to take anything for granted here. You know?
WZ:OK
MH So let me introduce you to our first dentist! His name is Philippe Hujoel… [Philippe Hue-zsh-oel]
PH as a kid i had nightmares about losing teeth. That I was sitting there and could remove one tooth after another. And I said well i don’t want that to happen to me so.
MH So he became a dentist - he’s also an epidemiologist and professor at the University of Washington.[12] And he told me about this pretty wild study that happened in the 1970s.[13]
SV_Cue_Ominous Curious_Stem_Keys_EM_v01-01
WZ okay…
MH They got a few hundred kids - who were around 12 years old, and randomized half of them to be in this special oral hygiene group to see if brushing and flossing did any good - if it actually prevented cavities. But - this wasn’t your standard brush for 2 minutes and you're good to go.
PH for 15 minutes[14] these kids go into a room, they brush their teeth[15]
MH: So imagine after math class, you have go to a special area, it’s called a “deplaquing” area, where there are toothbrushes, floss, mirrors all set up. You get to work.
WZ Oh god it’s like my worst nightmare…
MH And then to make sure these kids were actually doing a good job, the supervisor used a special red stain so the kids would see any spots they missed the first time they brushed and flossed
PH then the hygienist comes by shows what they missed and then she removes it.
MH Jeez
PH it’s an incredible amount of effort at trying to prevent cavities with oral hygiene. way more than a kid will ever get at home probably- you see a kid 15 minutes in a bathroom.
MH no yeah
PH I doubt it. do you think they will use these staining tablets, that the parents will come by, look with a pen light into the mouth and say hey you missed a spot on the back molar there.
MH The kids in the control group just got a toothbrush[16] every two months and were kind of told to keep brushing at home. But they didn’t get these extra tooth brushing parties. On top of that.
WZ Ok ok
MH And they did this for over 2 years of their lives.
WZ oh whoa!
MH So they were in the study from like when they're like 12 to when they’re like 14.
WZ But was it worth it? Was it worth it - all this work
PH So that was the amazing part. Oral hygiene did not prevent dental cavities.
WZ [GASP] What?? He said did not prevent - did not prevent cavities.
MH no - the kids who got all that extra brushing and flossing didn’t have fewer cavities. And it’s not just that one study - there are 3 studies that did similar stuff and Philippe did a review of all of them and none of them that brushing and flossing worked to prevent cavities.[17]
WZ WHAAAT - are you kidding me?
MH no
WZ whoaaa. So why doesn’t it work!? Because dentists have told us a very neat and tidy story about why brushing is supposed to help. You’ve heard it too right?
MH yeah of course - the brushing gets rid of the plaque - and that’s where the bacteria live. And bacteria are what cause cavities So yeah, I was … really surprised too, when I saw this. But, there is something you should know before you throw away your toothbrush all together. The toothpaste was missing something big. Fluoride.
PH it's always very important to stress. if these kids would have brushed with fluoride, you would have seen a reduction in cavities.
MH ohh
PH it's the fluoride it’s highly effective.
MH How solid is the evidence that brushing with a fluoridated toothpaste does work to prevent cavities?
PH extremely solid evidence, yes. many many randomized clinical trials which were starting in the 60s, and it keeps on going. so yes, the evidence there is unequivocal.
WZ ohhhh It’s the fluoride that does the job.
MH Yeah, overall, the best science we have on this is showing it's the fluoride that prevents cavities.[18]
WZ alright so what’s fluoride doing on your teeth that’s so important?
MH There’s a few different things[19]. One big one is that[20] when there’s fluoride in your mouth, it gets incorporated into the crystal structure of your teeth, and that makes them more resilient against cavities. It’s sort of like a shield against tooth decay.
WZ wow ok, ok. I’m still reeling from the fact that it’s not the act of brushing that’s doing this. It’s shoving fluoride onto your teeth that’s preventing cavities.
MH yeah! I mean, there’s also some evidence that the mechanical act of brushing your teeth- with or without fluoride - might be good for your gums – and reduce the risk of gingivitis.[21]
WZ: So it might be good for your gums?
MH: Yeah, but when it comes to cavities — brushing is just another way of getting fluoride onto your teeth. Like, a couple reviews[22][23] have found other ways of getting fluoride onto your teeth worked just as well. Like they’ll compare whether using fluoridated toothpaste was better than mouthwash with fluoride in it or fluoride varnish - that’s the stuff that the dentist puts on you. And they didn’t see any difference: the mouthwash with the fluoride in it was just as good at preventing cavities as the toothpaste!
PH So you have various options then to prevent cavities and they are equally effective if one goes by the randomized controlled trial evidence.
WZ And then, some people are afraid of fluoride.
WZ Is that a thing we need to be worried about?
MH: well the science does suggest there are a couple things we should keep an eye out for when using fluoridated toothpaste. So first there’s this thing called fluorosis - it can look like little white lines on the teeth?[24] I actually have some - I looked at my teeth earlier and was like oh I have a little of this. Getting a little of that staining is common if you grow up using fluoridated toothpaste.[25][26][27] But most of the time it’s but most of the time it’s pretty mild and it just affects how teeth look. Doesn’t cause any health problems.
WZ OK.
MH The other thing[28] is if you’re using fluoridated toothpaste with kids - which does work really well for preventing cavities! - you need to be careful that they don’t swallow too much of it. If you've got like, a four year old, should probably just use a pea sized amount on the brush - for younger kids, use even less..[29][30][31]
WZ So what happens if kids get too much fluoride?
MH Well, there are cases where kids eat too much toothpaste and then get stuff like nausea and vomiting. [32][33]
WZ oh ok
MH And then like theoretically, if anyone downs a whole tube of toothpaste it could be really bad.[34][35] But - I’m still a hundred percent going to give my kid fluoridated toothpaste for sure- I think the benefits definitely outweigh the risks.
Chapter 3: Flossing: Good for the gums?
WZ Ok so brushing with fluoridated toothpaste. Still good. Do that. Next question, flossing. Do I need to do it?
MH So yeah, do you remember that thing a few years ago where everyone was like, flossing may be a waste of time?
WZ oh yeah- it was huge, it was big news. Also because I really hate flossing. Every time I do it, my gums bleed. And every time i go to a dentist to tell them that, they’re like, that means you should be flossing even more.
MH I know. I like never floss and i have the gum bleeding thing too.
WZ yeah, so are we good?
MH Well, one thing those news stories got right was that there really isn’t great evidence that flossing can prevent cavities.[36][37] but
WZ interesting, but?
MH But there is better evidence that it can be good for your gums…[38].[39] and your gums are super important, obviously- they’re the thing that hold teeth into place! And I talked to another dentist about this - here's Dr. Alisha Virmani.
DA way i like to think about it. your teeth are almost like trees, and your gums are like the soil. So I’m sure you’re familiar with the idea of root rot? So if the soil becomes rotten, and there’s root rot, what happens to the tree? It’s gonna fall over, right
MH It dies?
DA the tree dies! It doesn’t live. you can have the most beautiful clean teeth, you can brush every single day, but if you’re not taking care of the soil of that tree, you’re not taking care of the gums, what’s going to hold your teeth in place?
MH Yeah, gums can start to get damaged because of the bacteria that’s hanging out near them. It can start this whole inflammatory reaction[40][41] that’s called gingivitis. And if that inflammation gets worse and worse - if it gets bad enough,[42] it can actually start backfiring, and attacking your gums and even your jaw bones can break down.[43]
WZ oh jeez so is this the cause of receding gums?
MH yeah - so this is why when you hear the phrase long in the tooth, it’s literally that as we get older your gums recede and it looks like your teeth are getting longer.[44]
WZ oh so you did know the phrase long in the tooth!
MH yeah but it means you're getting old.[45]
WZ ohh, hahaha. I thought it meant you were lying… Anyway. So the gums recede because your immune system is attacking the gums?
MH yeah, your body’s own immune reaction sort of destroys our gums and our jaws. And this is where flossing comes in.
WZ OK so how does flossing stop that from happening?
MH To be honest, we’re not exactly sure specifically what it’s doing. But dentists think that it might help to like sweep away the bacteria that's causing that whole immune reaction.[46][47] Alisha has an analogy for this.
DA a little bit of a gross analogy but it really does the trick, so bear with me, but if you were to go to the bathroom, you wouldn't just wipe your butt and leave the crack untouched, right? If you think of your bum the same way as your teeth, it’s disgusting, but that’s how disgusting it is when you don’t floss.
MH it's like leaving your butthole poopy?
DA yeah it is, its like going to the bathroom and not wiping your crack. it's gross! It is gross!
WZ powerful analogy. So that’s the purported mechanism. You’re getting rid of the poo or plaque in your teeth – which is filled with bacteria..
MH: Yeah, and we have some evidence that flossing can stop this inflammation reaction from getting out of control. Like, there's this study that found if you floss you're less likely to lose your teeth when you're older …
WZ ok well that feels like a very good reason to be flossing.
MH yeah- there are studies like that. But then on the other hand, I feel like I’ve been kind of struggling with all the research on how well flossing works. For one, a lot of the it is industry - funded,[48] so that doesn't make you feel great. And the best review I found on all of this… looked into how well flossing stops gingivitis. And they said it worked but that the evidence was low certainty.
WZ: Why low certainty? Cause of industry funding?
MH: No they listed a bunch of other reasons too. Like, some of the studies were really small - one only had like 6 people in it. Another thing was different studies found different things for how well it worked. Like some found a really big effect, some didn’t find anything at all. And on top of that, could be muddying the research - other people argue that flossing could work, it’s just that people don’t do it right.
WZ Ok so given all of this. You gonna floss Meryl?
MH yes..
Hahaha
MH Gonna get right on it.
WZ ok so, after the break, what’s going to happen?
MH Next we’re going to send an undercover agent to find out if all those fillings are just filling up the dentist's wallet.
WZ OOOH!!
BREAK
Chapter 4: Does seltzer mess up our teeth? What about other food and drinks?
WZ: Welcome back… we’re getting our fillings of science when it comes to the stuff dentists tell us… And we learned that brushing with fluoride does help prevent cavities, but it’s gotta have fluoride in it. Flossing?? Might be good for your gums…but dentists i’m putting you to work here. You want us to work here, get us better data.
MH: sounds about right.
WZ right? This is senior producer Meryl Horn. Meryl, what are we biting into next?
MH Let’s look at eating and drinking.
WZ oh yeah!
MH There was that whole thing with seltzer -- that was all over the news recently. Ok so the idea here is that seltzer is a little bit acidic and so it could eat away at our teeth.
WZ uh huh
MH But when I tried to find research on this there were only a few studies I could find… [49] Let me tell you about one of them[50] that got some media attention…[51] [52] [53]
MH Here's what they did. They kind of like....took some teeth.
WZ human teeth?
MH yeah - human teeth, from people, and then they —
WZ that were like removed for? You can’t just tell me they grabbed human teeth - we’re talking about dentists here, who knows what the fuck they’re doing?? Where did they get these teeth?
MH they got them from a dentist’s …
WZ cache? Tooth fairy had some on supply??
MH Ok, they apparently got them for an oral surgery department at a local hospital. And then they dropped these teeth into different drinks, and looked at how much the teeth eroded.
WZ Ok
MH Erosion is this different thing from cavities, it’s where the teeth kind of get worn away by acidic things. Ok, so here’s what they found. The teeth dropped into the seltzer were a little bit eroded.
WZ Ok are you worried about seltzer now?
MH Not exactly. Just generally these studies don't seem that realistic to me. Like, in that study that I just told you about - they took the tooth, dropped it into the seltzer for like 5 minutes, swirled it around – then took it out, rinsed it off, and dunked it back in, and did that whole thing like 6 times[54]…That's not how I drink seltzer
WZ: No!
MH Just generally you'd want to find studies in people… actually drinking seltzer and then looking to see how bad are their teeth? And i couldn’t find anything like that[55]. Plus when you look at the mechanism- seltzer isn't’ that acidic. Like it’s not actually as acidic as battery acid… By the way, one kind of annoying thing about that study which got all that attention is - one of the authors was from Perrier.
WZ ohh ok. Is coffee OK? That’s also acidic right?
MH Yeah, it’s sort of a similar story. With coffee. There’s a little research on human teeth, showing that it can wear them away.[56][57] But I haven’t been able to find any convincing studies in people, actually drinking coffee, showing they can have more problems with their teeth. And when I asked Philippe, the dentist from the top of the show, what he thinks of all this…
MH i've heard a lot that it's bad to sip coffee or bubbly water all day - is that true?
PH No, I don’t think so at all. No no,
MH Oh ok!
MH Philippe’s like all this talk about seltzer is taking away from the real problem which is sugar.
WZ Right - sugar
MH Sugar feeds the bacteria which make cavities in your teeth.[58][59]
PH if you think dental cavities- sugar, sucrose. That’s the main driver. It’s like tobacco is the main driver of lung cancer, sugar is exactly the same thing, it’s the main driver of getting dental cavities.
And Philippe told this story about what happened with him with sugar. .. like he’s always been prone to cavities.
PH yeah so I did everything right, I was having fluoride toothpaste, I was having fluoride rinses. I kept getting cavities.
WZ I’m secretly overjoyed by the fact that Philippe gets cavities. And he’s a dentist. Sorry Philippe! So what was he doing, was he eating a bunch of sugar?
MH basically yeah
PH i love bread i love pastries, my whole family - my whole ancestry was all bakers.
MH And one day, he just decided to go cold turkey on the candy. He had one last bag of gummy bears. And that was it. And it worked! He's never had another cavity.
WZ: Oh, wow
MH And when you look at the data – cutting down sugar - is probably the best thing you can do for your teeth..
PH Correct. If a person can just restrict sucrose, 80% of cavities will be prevented
MH 80%?
PH 80%
MH Whoa.
WZ 80% is a lot!
MH Yeah that number comes from people who are fructose intolerant,[60][61] who can't eat certain carbs or sugars[62] – and they get 80% less tooth decay than other people.
WZ So Philippe eliminated sugars from his diet - that feels rather extreme. Do we need to be doing that?
MH i mean, studies find that the more sugar you eat, the more cavities you get.[63][64] So it’s not an all or none thing. So even if you eat less sugar, you should be getting less cavities.[65][66] And if you're getting a bunch of cavities - it’s not just sugar- genetics plays a role here too.[67][68] But overall, sugar is really the thing that makes or breaks your teeth.
Chapter 5: How dodgy are dentists?
BH_SV_Cue_Obscured_v01-01
MH OK - there’s one more thing I wanted to look at - that’s what happens at the dentist office… can we really trust them??
WZ yes- cause it’s like often when I’ve gone to the dentist for a cleaning, they’ll be like, oh, you need a filling here and a filling there. And I do have a lot of fillings. Did I need them all?
MH yeah! I want to know. And I found this amazing study. The goal was to find out how often dentists recommended treatments that aren’t really necessary. And it was run by Felix Gottschalk, he’s an economist actually... he’s from Germany but lives in Switzerland now.
FG In the end it's a study that's very entertaining to talk about
Felix and his team found a guy[69]
FG He was a student at the university
MH the plan was to get him to pretend to be a patient, and send him out to a bunch of different dentists and see what they tell him.
WZ This is amazing.
MH To start with, they had his teeth carefully examined by 4 dentists that they trusted, who used the official Swiss Dental Association guidelines to figure out what kind of work he really needed. There was one little spot that was sort of the beginning of a cavity … But all 4 of these dentists independently said that it didn’t need treatment. So 4 out of 4 dentists agreed that he could just brush at home and get it checked in a year.[70] Ok, so that’s our undercover agent - our fake patient. Then Felix had him hit the road …
FG so we sent 1 test patient to 180 dentists
MH Oh my god
FG within almost 1 year so this test patient visited 5 dentists every week for one year.
MH that's a lot haha.
MH Did he ever want to quit?
FG No, he never wanted to quit, because we paid him well, I guess!
MH So this guy does his great dental tour of Zurich and the surrounding countryside… then Felix looked at the data. Are you ready?
WZ I’m ready! What on earth did all these dentists say?
MH First, the good news. Most of them said he didn’t need any treatment! About two-thirds of them - told him he didn’t need any fillings at all. But about 30% of them told him he did need work done. That he did need fillings. In some cases, a lot of them.
FG In around one third of the visits, the patient was advised to be given between 1 and 6 fillings
WZ 6 fillings!? Oh wow
MH Yeah - and he didn’t need any fillings at all. All together, these unnecessary treatments would have cost an average of about 500 euros.[71]
WZ wooow.
MH And the filling recommendations were all over the place in his mouth.
FG One interesting detail is that treatment, filling recommendations were given in total for at least 13 different teeth.
MH huh, but, but you knew already that he didn’t have anything like a cavity on most of his teeth. What does that mean?
FG well we don’t know what it means. We just can say this is quite strange, it has a taste, as we say in southern germany.
WZ it has a taste like the taste of crap - the taste of bullshit.
MH And there’s another twist to the study that I really want to tell you about. So, they actually had this guy do costume changes. Like sometimes he was dressed up like a rich guy and sometimes he was dressed up like an average guy - to see whether the dentists treated him differently based on how much money he had. Do you want to see the outfits?[72]
WZ yes I want to see the outfits! Wasn’t expecting you to ask that. Slack it?
WZ ok so, this is pretty standard, the low SES, socioeconomic status is an outfit that I would wear. Grey hoodie and jeans- backpack. And then the high SES is someone with a pretty nice suit, and leather shoes and a nice watch. So what did the dentists do, did they overcharge the rich one?
FG from an economic standpoint, you’d expect that patient, would be charged higher fees, or also receive more overtreatment recommendations. But as it turns out, we saw an opposite result
WZ Gasp
MH Yeah, so the guy in the hoodie- when it looked like he had less money, he was recommended more stuff!
WZ was that because - is there any theory? They thought they could hoodwink him more?
MH Yeah I mean, we don’t know for sure, I asked Felix and he said maybe dentists wanted to treat the guy who seemed richer better so he’d stick around as a patient.
WZ hmmm
FG Dentists may want to build up a long term relationship for higher future profits for instance.
MH Ohhh Play a long game
FG play a long game. That could be a reason.
MH Felix also found that dentists who had a shorter amount of waiting time for an appointment recommended more fillings. Maybe because they needed the money if their practice was a little less busy?
WZ right
MH And there’s another study[73] that backs up this picture. It surveyed around a thousand dentists in Canada - they found that the more the dentists owed in student loans, the more likely they were to say that patients needed really intense treatments that they didn’t need.
WZ ohhh!
MH yeah
MH and so now whenever you go to the dentist, do you push back a little more when you get told you need a filling?
FG Ahh yes, I actually went to a dentist and received a recommendation for a filling. And I hesitated, and then my wife said I should rather visit her dentist, because she trusted her dentist very much and thought she was quite good. And I went to her dentist and this dentist did not recommend anything. So one result from the study is probably also that it helps to get second opinions, right? Because in the majority of cases, the treatment recommendation was correct. And if you receive several opinions, you increase the size of your personal dental study, so to say.
MH yup.. that’s a nice take-away
Mix_Conclusion_VersionA-01
MH Alright what have you learned, Wendy?
WZ Oh wow, a test! A test! Brushing with fluoride toothpaste helps prevent cavities. Brushing also might prevent gingivitis - gum disease. Flossing - the research is a little bit of a shit show. But the best research we have suggests as you get older it may help with tooth loss. Not sure why - might be because it helps your gums. Sugar is bad for your teeth. Don't worry about seltzer. Some dentists are shysters. Not most of them, but some. How’d I do?
MH i think you got it. Nice job - you passed. Is there - I’m curious if there’s anything you’ll do differently.
WZ Do you know, Meryl, I love going to bed with a little bit of chocolate.
MH hahah that’s like the worst thing you can do.[74]
WZ I know, I know. Like I love brushing my teeth, drinking some water, and then going to bed with chocolate.
MH yeah you might want to stop that.
WZ yeah yeah. Yeahhhhhhhh. Thanks, Meryl!
MH Thanks Wendy.
That’s Science Vs
Chat:
CREDITS
This episode was produced by Meryl Horn, with help from Wendy Zukerman, R.E. Natowicz, Rose Rimler, Michelle Dang and Joel Werner. We’re edited by Blythe Terrell. Gimlet’s managing director is Nicole Beemsterboer. Fact checking by Erica Akiko Howard. Mix and sound design by Bobby Lord. Music written by Bobby Lord, Peter Leonard, and Bumi Hidaka. Thanks to all the researchers we spoke to, including Dr. Joshua Emrick, Dr. Arosha Weerakoon, Professor Stephen Peckham, Professor Marie Bismark, Professor Steven Levy, Dr. Abdul Ghoneim, Dr. David Okano, Professor Christof Dörfer, and Dr. Patrick Fee. Special thanks to Chris Suter, the Zukerman Family and Joseph Lavelle Wilson.
Science Vs is a Spotify Original Podcast and a Gimlet production. Follow Science Vs on Spotify, and if you want to get notifications every time we put out a new episode, tap the bell icon in your app.
[1] https://www.forbes.com/sites/rosspomeroy/2013/10/17/dentists-say-you-need-to-floss-science-says-you-dont/?sh=68d84f0e3083
[2] https://www.tandfonline.com/doi/abs/10.1080/03036758.2019.1656649 New Zealand survey: “Most respondents (90%) brushed their teeth more than once daily, while substantial minorities flossed once a day (45%)...”
[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4095631/ survey from India. of 255 dentists: “15.3% of the respondents do not floss at all, 46.3% of them floss occasionally, 22% floss once a day or more, and 9.4% floss on alternate days [Figure 2]. 28.2% of the dentists use some other interdental aid like toothpicks and interdental toothbrushes apart from dental floss.”
[4] another survey of dentists in India - “9.2% of them reported that they flossed at least once daily [Table 1].”
[5] https://pubmed.ncbi.nlm.nih.gov/12027256/ US - “Frequencies of flossing at least once daily were...56.3% for dentists... (Fig. 2)” (all dentists in this survey were male)
[6] https://www.huffingtonpost.co.uk/entry/sparkling-water-is-extremely-acidic-and-can-ruin-teeth-dentist-warns_uk_59030840e4b02655f83b8868 (OG Story:https://www.dailymail.co.uk/health/article-4453682/How-sparkling-water-wrecking-teeth.html#ixzz4fWk06K85)
[7] https://www.youtube.com/watch?v=LtV6VuPhHMQ 5 months ago. [*Note from us: sparkling water is actually not nearly as acidic as battery acid.]
[8] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2626328/pdf/16211157.pdf “Dental caries is still a major health problem in most industrialized countries as it affects 60–90% of school-aged children and the vast majority of adults.”
[9] “Among adolescents aged 12 to 19, more than half (57%) have had a cavity in their permanent teeth.1
Among adults aged 20 and older, about 90% have had at least one cavity.2 1 in 4 adults aged 20 to 64 currently has at least one cavity.2”
[10] https://www.cdc.gov/oralhealth/fast-facts/tooth-loss/index.html “Severe tooth loss—having 8 or fewer teeth—impacts the ability to eat meats, fruits, and vegetables, and presents yet another challenge to having a healthy diet.1…About 1 in 6 (17%) adults aged 65 or older have lost all of their teeth.3”
[11] https://pubmed.ncbi.nlm.nih.gov/21883422/ Physical dimensions, characterised by the difficulties in eating and social dimensions, because of interference in communication with other people were obtained.
[12] https://dental.washington.edu/people/philippe-p-hujoel/; https://epi.washington.edu/faculty/hujoel-philippe/
[14] “The daily regimen proceeded as follows: children in groups of 12-15 assembled for a 15-min session at a specified time at a designated deplaquing area at each school. The students sat at tables and each was provided a toothbrush, a mouth mirror, dental floss, fluoride-free dentifrice, a free standing face mirror and necessary paper products….This paper presents final results obtained after 32 months of study.”
[15] This is an intermediate report (2 years in) from the same study: “During the second school year, the dental hygienist who had been in charge of the daily deplaquing sessions resigned. To replace her, a local registered nurse who was already employed in the program was appointed as the fulltime co-ordinator.”
[16] “The control group was not provided with instruction nor did they engage in plaque removal in school. Both groups, however, were given toothbrushes every other month for ad libitum use at home”
[17] https://onlinelibrary.wiley.com/doi/epdf/10.1111/ger.12331 “Three randomised studies involving a total of 743 participants were included. Personal oral hygiene interventions failed to influence the incidence of dental caries…” [the one that got closest to seeing a significant benefit was Horowitz - see Figure 3, but that paper says “Adjusted mean incremental DMF [decayed, missing, and filled] surface scores were 13 % lower in the treatment group than in the control group. The difference between groups was not statistically significant”
[18] https://pubmed.ncbi.nlm.nih.gov/12535435/ “Seventy-four studies were included…Supported by more than half a century of research, the benefits of fluoride toothpastes are firmly established. Taken together, the trials are of relatively high quality, and provide clear evidence that fluoride toothpastes are efficacious in preventing caries.”
[19] https://pubmed.ncbi.nlm.nih.gov/21701194/ “Although the main action of fluoride on the dynamics of dental caries is on de- and remineralization processes that occur on dental hard tissues, it has also been proposed that the fluoride ion can affect the physiology of microbial cells,...Evidence from cohort studies also supports fluoride’s systemic mechanism of caries inhibition in pit and fissure surfaces of permanent first molars when it is incorporated into these teeth pre- eruptively.”
[20] https://pubmed.ncbi.nlm.nih.gov/21701194/ “If fluoride is present in plaque fluid (FL) when bacteria produce acids, it will penetrate along with the acids at the subsurface, adsorb to the crystal surface (FA) and protect crystals from dissolution [26]. …Fluoride present in low, sustained concentrations (sub- ppm range) in the oral fluids during an acidic challenge is able to absorb to the surface of the apatite crystals, inhibiting demineralization….” Also See figure 9
[21] https://www.cochrane.org/CD002281/ORAL_poweredelectric-toothbrushes-compared-to-manual-toothbrushes-for-maintaining-oral-health “The evidence produced shows benefits in using a powered toothbrush when compared with a manual toothbrush. There was an 11% reduction in plaque at one to three months of use, and a 21% reduction in plaque when assessed after three months of use. For gingivitis, there was a 6% reduction at one to three months of use and an 11% reduction when assessed after three months of use.”
[22] https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD002780.pub2/full “Fluoride toothpastes in comparison to mouth rinses or gels appear to have a similar degree of effectiveness for the prevention of dental caries in children.”
[23] "Objective: To illustrate the potential and challenges of the simultaneous analysis of a network of trials, using as a case study the investigation of the relative effectiveness of four topical fluoride treatments and two control interventions (placebo and no treatment) in preventing dental caries in children. ... Conclusion: After adjusting for possible differences across studies, we did not find clear evidence that any topical fluoride modality is more effective than any other." (https://pubmed.ncbi.nlm.nih.gov/19157778
[24] https://www.researchgate.net/publication/344244165_Clinical_Performance_of_Enamel_Microabrasion_for_Esthetic_Management_of_Stained_Dental_Fluorosis_Teeth See Figure 1… “TF score” 1 = “thin white lines are seen running across the tooth surface…” TF
[25] "Dental fluorosis is caused by taking in too much fluoride over a long period when the teeth are forming under the gums. Only children aged 8 years and younger are at risk because this is when permanent teeth are developing; children older than 8 years, adolescents, and adults cannot develop dental fluorosis." https://www.cdc.gov/fluoridation/faqs/dental_fluorosis/index.htm#:~:text=Dental%20fluorosis%20is%20caused%20by,adults%20cannot%20develop%20dental%20fluorosis.
[26] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8078481 “There is some evidence that brushing a child's teeth with a toothpaste containing fluoride, before the age of 12 months, may be associated with an increased risk of developing fluorosis. There is stronger evidence that higher levels of fluoride (1000 parts per million (ppm) or more) in toothpaste are associated with an increased risk of fluorosis when given to children under 5 to 6 years of age. However, for some children (those considered to be at high risk of tooth decay by their dentist), the benefit to health of preventing decay may outweigh the risk of fluorosis…Although the very mild forms of dental fluorosis do not pose a public health problem, more severe forms will be of aesthetic concern, especially when the upper front teeth are substantially involved.”
[27] E.G. - best study from cochrane review
“In the less deprived districts the prevalences of fluorosis (TF ≧0) for the 1,450- and 440-ppm F groups were 34.5 and 23.7% (p = 0.006). In the deprived districts the prevalences of fluorosis were 25.2 and 19.5% (p = 0.2)...The results demonstrate that children who received the 1,450-ppm F toothpaste had significantly more fluorosis (TF > 0) than those receiving 440 ppm F. The majority of fluorosis was mild (TF 1–2) and of no aesthetic concern. However, some children had TF scores of 3 or 4 and this might be considered aesthetically objectionable”
[28] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9289262/ “The harmful effects of fluoride exposure may be placed into two main categories: Firstly, a massive acute systemic exposure from an industrial accident, and inadvertent ingestions of large quantities of fluoride anion-containing products have been observed…Secondly, a mild chronic overexposure to fluoride in children over time may result in some form of fluorosis in developing teeth, and may also cause a transient gastric disturbance”
[29] “CDC, AAP, AAPD, and ADA recommend that children aged 3–6 years brush their teeth twice daily using a pea-sized amount of fluoride toothpaste. Supervision is emphasized as a critical role for the parent or caregiver as the child first begins using a toothbrush and toothpaste.”
[30] https://pubmed.ncbi.nlm.nih.gov/24487610/ “Several organizations now recommend using a smear of toothpaste—or an amount the size of a grain of rice—in children younger than 2 years and then a pea-sized amount starting at age 2 years.”
[31] https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1600-0528.1994.tb01836.x?sid=nlm%3Apubmed “...small quantities should be used with parental direction and supervision so that inappropriate "eating" of fluoride dentifrice is avoided (3, 5),”
[32] “Primarily, the stomach is affected, and the first symptoms and signs consist of nausea, abdominal pain, bloody vomiting and diarrhea. … There have been cases reported of children eating toothpaste, a situation giving rise to nausea and vomiting.
[33] See table 3 In 1994, there were 3,339 reports to Poison Control of overconsumption of toothpaste. 800 of those had a “minor effect” which are “minimally bothersome signs or symptoms that generally resolved without residual disability or disfigurement” (e.g., gastrointestinal effect) -- “At lower dosages, acute fluoride toxicity appears as nausea, upset stomach, and vomiting”; N.B.: no deaths from toothpaste identified here between 1989 and 1994
[34]“Estimates of the lethal oral dose of sodium fluoride vary substantially… Hodge and Smith estimated that the certainly lethal dose (CLD) for adults ranged from 32 to 64 mg F/kg body weight. Within this range, every 70 kg adult would be expected to die. Hodge and Smith estimated that the certainly lethal dose (CLD) for adults ranged from 32 to 64 mg F/kg body weight. Within this range, every 70 kg adult would be expected to die.” (See note below: A standard tube of toothpaste is 125g and contains 1100 ppm F)
[35] https://pubmed.ncbi.nlm.nih.gov/12535435/ “Although acute toxicity is extremely rare, young children are particularly at risk of ingesting toxic doses of fluoride from a standard toothpaste tube of 125 g, generally containing 1100 ppm F (1.1 mgF/g paste). As the probable toxic dose (PTD) is around 5 mgF/ kg body weight (Whitford 1992), the accidental swallowing of one-third of a toothpaste tube (45 g) or two-thirds of it (90 g) is potentially life-threatening for a 1-year-old (10 kg) or for a 5 to 6- year-old (20 kg) respectively (Ellwood 1998). For this reason it is recommended that a fluoride toothpaste tube should be kept out of the reach of young children.”
[36] FLOSSING/CAVITIES: Latest cochrane review on this: https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD012018.pub2/full “For caries outcomes, we intended to calculate the prevented fraction (PF), where appropriate. …The findings do not allow us to be certain whether or not home use of interdental cleaning devices makes a clinically significant impact on periodontal diseases, and they provide no information about the impact on dental caries.” [none of the trials that met their standards measured caries]
[37] https://journals.sagepub.com/doi/abs/10.1177/154405910608500404 “...self-performed flossing in young adolescents for 2 years (relative risk, 1.01; 95% confidence interval, 0.85–1.20; p-value, 0.93) did not reduce caries risk….Professional flossing in children with low fluoride exposures is highly effective in reducing interproximal caries risk. These findings should be extrapolated to more typical floss-users with care, since self-flossing has failed to show an effect. [note - one of the 2 studies on professional flossing was funded by Johnson & Johnson: https://www.aapd.org/globalassets/media/publications/archives/wright-02-02.pdf - “This research was supported by a grant courtesy of Johnson & Johnson Co. Ltd.”]
[38] https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD012018.pub2/full “Low‐certainty evidence suggested that flossing, in addition to toothbrushing, may reduce gingivitis (measured by gingival index (GI)) at one month (SMD ‐0.58, 95% confidence interval (CI) ‐1.12 to ‐0.04; 8 trials, 585 participants), three months or six months.”
[39] 2022 Londero et al RCT full text/download.. 60 days… “randomized into two groups either performing toothbrushing supplemented by dental floss (TB + DF) or toothbrushing (TB) alone. … Interproximal gingival inflammation (GI = 2 and mean GI) was significantly reduced in both groups by day 30, reduction in inflammation being significantly greater in the TB + DF compared with the TB alone group.”
[40] “The metabolic products of bacteria trigger junctional epithelium cells to produce cytokines and stimulate neutrons to produce neuropeptides, which cause vasodilatation of local blood vessels. Neutrophils leave the vessel and migrate toward the site of inflammation in response to chemokines…. and clinical signs of gingival inflammation, such as bleeding, can be seen.”
[41] “The development of periodontitis correlated with increased complexity of the cellular infiltrate composition from one dominated by neutrophils (initial lesion) to one containing elevated numbers of macrophages and T cells (early lesion) and, additionally, B and plasma cells that predominate in the established and advanced lesions.”
[42] “Gingivitis has been shown to be a risk factor in the clinical course of chronic periodontitis (Schatzle 2004). This 26‐year longitudinal study, found that teeth with inflamed gingivae were at much higher risk (46 times) of being lost compared to teeth that had inflammation‐free gingivae.”
[43] “Tumor necrosis factor alpha is a multi-effect cytokine that has many functions, from cell migration to tissue destruction…. Tumor necrosis factor alpha is also correlated with extracellular matrix degradation and bone resorption through actions promoting the secretion of matrix metalloproteinases and RANKL (62, 72, 73) and coupled bone formation”
[44] Periodontal diseases can manifest in several ways. … More severe symptoms at the time of presentation include pain and tenderness during chewing of specific substances, sensitive teeth, receding gums, the formation of discoloring plaque, tooth mobility, and even loss of teeth….Chronic periodontitis can present in patients of any age, but most often affects middle-aged to older adults.
[45] https://www.merriam-webster.com/thesaurus/long%20in%20the%20tooth#:~:text=phrase,be%20hitting%20those%20steep%20slopes. as in older being of advanced years and especially past middle age
[46] https://pubmed.ncbi.nlm.nih.gov/28540937/ “Tooth surfaces are covered by a conditioning film of proteins and glycoproteins (the acquired pellicle) that are derived mainly from saliva, but it also contains bacterial components and their products, gingival crevicular fluid… blood and food”
[47] https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD012018.pub2/full
"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. ... Overall, the evidence was low to very low‐certainty, and the effect sizes observed may not be clinically important."
[48] https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD012018.pub2/epdf/full “We categorised 24 studies as industry funded (69%)...“ this includes many of the studies on flossing: Cronin 1997 and Isaacs 1999 were supported by Braun AG, Germany (Braun Oral-B Interclean ID2); Yankell 2002 by Dental Concepts, Paramus, USA (oral hygiene devices); Jackson 2006 and Schiff 2006 by the Colgate Palmolive Company (toothbrushes, floss and toothpaste); Meklas 1972 by the General Electric Company (Aqua Pulse Oral Irrigator); Zimmer 2006 and Ishak 2007 by GlaxoSmithKline (manual toothbrush and floss); Finkelstein 1990 by Johnson & Johnson (waxed floss); Cronin 2005 by Oral-B (manual toothbrush and flosser); Biesbrock 2007; NCT00855933 and Rosema 2008 by Procter and Gamble (sponsorship) (DE International supplied the toothpaste for Rosema 2008); Yost 2006 and Jared 2005 by Sunstar Inc. (GUM, manual toothbrush); Barnes 2005, Goyal 2012 and Rosema 2011 by Waterpik Inc., Fort Collins, USA (oral irrigator); Hague 2007 by William Getgey Company (ultra-flosser); and NCT01250769 was sponsored by Philips Oral Healthcare. Walsh 1989 was partially funded by Xouth, Inc, Lancaster, PA, USA. In Bauroth 2003, the authors were affiliated to industry, Pfizer; in Frascella 2000, the authors were affiliated to Braun and Procter and Gamble; and in Mwatha 2017, the authors AM, MO, SS, MW and WJ were employees of Philips (Sonicare Toothbrush).
“...many of the meta-analyses only included a small number of trials and participants.” See P 118 - analysis 1.1 shows heterogeneity and study with N= 6
“The body of evidence for this comparison for both gingivitis and plaque was low- and very low-certainty, respectively, due to the risk of bias in the studies, substantial unexplained heterogeneity, and lack of precision in the effect estimates.” “Most of the trials in this review were of short duration and involved many participants with only a low level of gum inflammation at baseline. In addition, all studies were at risk of performance bias, and 33 of the 35 included trials were at risk of other types of bias.”
[49] https://onlinelibrary.wiley.com/doi/abs/10.1046/j.1365-2842.2001.00795.x “Sparkling mineral waters showed slightly greater dissolution than still waters, but levels remained low and were of the order of one hundred times less than the comparator soft drinks. … Teeth used in this study were sound extracted permanent human teeth from the Oral Surgery Department of the Birmingham Dental Hospital.”
[50] Found other similar studies, but not comparing seltzer/mineral water to other stuff. E.g. this one doesn’t have those drinks (Table 1), this one doesn’t have those drinks (see table 1 for drinks), this one does look at mean hydroxyapatite dissolution in several unnamed brands of sparkling flavored water compared to orange juice,and found they were similar “All of the flavoured water drinks examined here were observed to cause hydroxyapatite dissolution of the same order as or greater than the positive control drink, pure orange juice.” but no water or sugary soda comparison
[51] https://www.theatlantic.com/health/archive/2016/02/the-sad-truth-about-seltzer/433947/ mentions a couple of these studies: “One 2007 study in which researchers exposed human teeth to flavored sparkling waters for 30 minutes found the waters to be roughly as corrosive as orange juice. “” and this is the one we discuss “The good news is that La Croix and its ilk are still likely far less damaging to teeth than regular soda.
[52] https://www.verywellhealth.com/is-mineral-water-harmful-to-your-teeth-1059307 in sources “Investigation of mineral waters and soft drinks in relation to dental erosion."
[53] https://www.drweil.com/health-wellness/body-mind-spirit/dental-oral-health/does-seltzer-rot-teeth/ in sources “Investigation of mineral waters and soft drinks in relation to dental erosion."”
[54] https://onlinelibrary.wiley.com/doi/abs/10.1046/j.1365-2842.2001.00795.x teeth were subjected to six consecutive 5-min exposures to the test solutions. For each test solution, eight teeth were individually incubated in 1 mL of the test solutions at 37 °C with gentle agitation for every exposure. After each exposure, the incubation solution was collected from the tooth together with 1 mL of deionized distilled water which was used to wash the surface of the experimental window.
[55] https://www.mdpi.com/2072-6643/15/7/1785 Note: This 2023 review looks at the effects of carbonated soft drinks on enamel. In Table 2 it lists in vivo studies, and none are on plain unsweetened carbonated water.
[56] https://jpma.org.pk/article-details/7824?article_id=7824 CocaCola was found to be the most erosive agent among both hot and cold beverages (37%), while coffee was more erosive among the hot beverages (29%).... Coffee-treated teeth showed an increase in Ra by up to 29% (p<0.05), followed by orange juice 18% (p<0.05). Tea showed a minimal increase of only 8% (p<0.05) in Ra.
[57]The results showed that there were statistically significant differences in tooth surface hardness in coffee, tea, and milk groups compared to the control group.
[58] Mechanism: “Acidogenic plaque bacteria utilise dietary sugars to demineralise dental tissues, which may progress into carious tooth lesions.”
[59] “Caries is caused by the dissolution of the teeth by acid produced by the metabolism of dietary carbohydrates by oral bacteria”
[60] Newbrun https://jada.ada.org/article/S0002-8177(80)14019-8/pdf examined 17 people with hereditary intolerance, and 14 controls (8 of them were blood relatives). Had roughly same diet in other ways, but much less sucrose. 2.5 gm/dy vs 48.2 gm/day. Results: plaque was similar, but “subjects with HFI [hereditary fructose intolerance] had a mean DMFT [Decayed, Missing, and Filled Teeth] of 2.1 and a mean DMFS [Decayed, Missing, and Filled Surfaces] of 3.3 compared with a mean DMFT of 14.3 and a mean DMFS of 36.1 for control subjects….” Table: Percent caries free: 59% HFI subjects, 0% Control subjects “...no reasonable person would deny that frequent consumption of sugars by caries-susceptible humans will result in the development of dental caries.” [math: 2.1 vs. 14.3 = 85% reduction; 3.3 vs 36.1 = 90.9% reduction]
[61] https://pubmed.ncbi.nlm.nih.gov/2704977/ L Saxén et al: “Therefore 18 patient with HFI [hereditary fructose intolerance] were examined for the following parameters: radiographic bone loss, caries rate…” Table 1: caries indices [DMF(T) (number of decayed, missing, and filled teeth) + def (number of decayed, extracted and filled primary teeth)] for HFI patients = 2, for controls = 10.4 [math: 2 vs 10.4 = 80.8% reduction]
[62] https://www.ncbi.nlm.nih.gov/books/NBK333439/ See table 9
[63] https://www.ncbi.nlm.nih.gov/books/NBK285538/#:~:text=In%20both%20adults%20and%20children,intake%20(conditional%20recommendation8) “The evidence suggests higher rates of dental caries when the level of free sugars intake is more than 10% of total energy intake compared with it being less than 10% of total energy intake.”
[64] Table 3. “Mean dmfs scores of 5- and 8-year-old children who consumed sweet snacks between meals more than 5 times a day (according to parents' reports) were significantly higher than mean dmfs scores of children with a lower reported sweet snack consumption” [dmfs = decaryed, missing, filled surfaces]
[65] https://www.ncbi.nlm.nih.gov/books/NBK285538/#:~:text=In%20both%20adults%20and%20children,intake%20(conditional%20recommendation8) “The evidence suggests higher rates of dental caries when the level of free sugars intake is more than 10% of total energy intake compared with it being less than 10% of total energy intake.”
[66] Table 3. “Mean dmfs scores of 5- and 8-year-old children who consumed sweet snacks between meals more than 5 times a day (according to parents' reports) were significantly higher than mean dmfs scores of children with a lower reported sweet snack consumption” [dmfs = decaryed, missing, filled surfaces]
[67] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4449725 “Indeed, previous studies have shown that dental caries is highly heritable, with 20–65% of variation attributable to genetics …”
[68] E.g. “Although subjects were reared in different environments, received different diets and different professional dental care, the MZ [monozygotic] data demonstrated that a significant proportion of variance (45-67%) for the number of teeth present, number of teeth and surfaces restored, and the caries present was attributable to genetic variance.” Table 4
[69] https://www.aeaweb.org/conference/2018/preliminary/paper/Br9Gh7fd PDF of preliminary version. Final copy of published version here
[70] “Based on the x-ray and an inspection of the patient, all four reference dentists stated independently that the superficial caries lesion had not yet progressed to the dentin and should hence not be treated according to the treatment guidelines.”
[71] “Conditional on an overtreatment recommendation, mean overtreatment costs taken from the collected cost estimates amount to 535 Swiss Francs (CHF, about $550)...” (This was in 2016.)
[73] https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0233652 “Age (p = 0.001), place of initial training (p<0.001), number of dependents (p = 0.001), number of hygienists employed (p = 0.001), and perceptions of practice loans (p = 0.020) were associated with treatment intensity.” “Among dentists who have student loans, those who perceive these loans to be large have 50% greater odds (OR: 1.48; 95% CI: 0.96–2.29, p = 0.078) of reporting relatively aggressive treatment decisions than those who perceive their loans as small. Similarly, dentists who perceive their practice loans as large or medium have 60% (OR: 1.57; 95% CI: 1.02–2.42, p = 0.039) and 80% (OR: 1.76; 95% CI: 1.18–2.61, p = 0.005) higher odds of reporting relatively aggressive treatment decisions, respectively, than those with no loans.”
[74] https://pubmed.ncbi.nlm.nih.gov/28561551/ The consumption of free sugars within the hour before bed revealed a statistically significant difference between the cavity/no cavity groups (p=0.002). Logistic regression analysis on the cavity/no cavity groups revealed an odds ratio of 2.4 (95%CI 1.3,4.4) for free sugars consumption before bedtime….Conclusions: The study suggests that the consumption of free sugars before bedtime may be an important risk factor for adolescent caries into dentine experience.