Fluoride Flak: Dental Experts Weigh In

Many of us have been told for most of our lives that fluoride is greatly beneficial to our health. So how did we get from fluoride in the public water supply being one of history’s great public health achievements to it standing trial in the court of public opinion? We invite Drs. Bina Katechia and Aadarsh Gopalakrishna from the UConn School of Dental Medicine to deliberate and render a verdict.

(Dr. Bina Katechia, Dr. Aadarsh Gopalakrishna, Carolyn Pennington, Chris DeFrancesco, February 2025, studio and technical support by Ethan Giorgetti)

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Transcript

Chris: Who knew there could be such a debate over something that’s been in our water supply for 80 years? Today on the Pulse, we talk about fluoride.

This is the UConn Health Pulse, a podcast to help you get to know UConn Health and its people a little better, and ideally leave you with some health information you’ll find useful. With Carolyn Pennington, I’m Chris DeFrancesco.

Fluoride is associated with improved dental health by strengthening teeth and reducing the risk of cavities.

Carolyn: But despite a long run of wide acceptance as a great public health intervention, there are now calls to stop adding fluoride to the water we drink. So today, we’ve invited two members of the UConn School of Dental Medicine faculty, Dr. Aadarsh Gopalakrishna, chair of the Division of General Dentistry, and Dr. Bina Katechia, interim chair of the Department of Pediatric Dentistry. Thank you both for joining us.

Dr. Gopalakrishna: Thank you for having us over.

Dr. Katechia: Yeah, pleasure to be here.

Carolyn: Now, let’s start with the basics. What is fluoride and how does it improve our oral health?

Dr. Katechia: Great question. So before we answer that, let’s just go over what tooth decay is and how it develops.

So tooth decay is common. It’s also known in our community as dental caries–

Carolyn: Or cavities?

Dr. Katechia: Or cavities, and it occurs when bacteria metabolize the sugars and carbohydrates that we eat. And they metabolize those, produce acids, and then those acids will eat away our tooth enamel. So what happens is, if this continues, our teeth begin to demineralize and then you get the formation of small holes or cavities, which go on to develop bigger holes.

So if we now look at fluoride, fluoride has a very beneficial effect on preventing tooth decay. It has three different different routes of helping to prevent decay.

If we look at systemic fluoride first, if we ingest fluoride in water, let’s say, in developing teeth, it will incorporate into the tooth enamel itself and produce an outer layer that’s a little bit more resistant to decay. So teeth start developing in utero at four or five months of a developing fetus. And so it incorporates into the developing teeth to make them a little bit more resistant to decay, and this goes on throughout your life as your teeth are developing.

Now, topical fluoride, when it’s in, mixed with saliva, will

Carolyn: Like when you’re toothpaste or something? Is that what you’re–

Dr. Katechia: yes, so in the water or toothpaste, it will mix with that and help be protective towards that layer of enamel and help to remineralize anything that’s just started to demineralize.

Thirdly, it can also affect bacteria that are metabolizing these sugars, and kind of disrupt their metabolic pathways so they don’t produce as much acid is as usual. So it reduces that acid production by bacteria.

Carolyn: But what is fluoride?

Dr. Gopalakrishna: So if you’re looking at fluoride, again, it’s amongst us. It’s a mineral. basically, it’s naturally occurring. You could find that in soil, rocks or water. So that’s something which has been among us. And, as we are looking at benefits of fluoride, one of the things is the ongoing use of fluoride. Specifically, how the cavity forms, as Dr. Katechia was telling us; it’s the breakdown of the acid, which is one of the byproducts of the bacteria which causes the cavity or the caries. But what fluoride does is it just makes the structure of the tooth itself a little more resilient to breakdown of that acid.

And that’s kind of what stands out with what the benefits of fluoride is, along with it also benefits from remineralizing, putting the mineral back into the enamel. So it makes it a little more resistant to breakdown for cavity or caries.

Chris: We know it’s good for us.

Carolyn: How do we know it’s good for us though? Have there been a lot of test studies?

Dr. Katechia: There’s multiple studies that have been going on for decades now. And fluoride was introduced into community water supply in the mid 40s. There’s been so many multiple studies done on the benefits of fluoride, but there’s also studies that show when communities have removed fluoride from their water, then cavities tend to increase.

Chris: So what’s the, do we have general guidance from the dental community on how to use fluoride to our advantage and take advantage of the benefits?

Dr. Gopalakrishna: Besides having a very long track record of having fluoride in many forms, let it be a local use like in the form of a toothpaste or a systemic use as in water, there’s a long standing support not only in terms of research, but in terms of national organizations, American Dental Association and the cardiology and the pediatric areas, all of these areas are promoting to make use of the benefits of the fluoride in terms of keeping the teeth a little more stronger and resilient to caries or cavities.

Carolyn: So how did these conspiracy theories start? I mean, if we have all this proof and, I mean, I don’t have any cavities. Because, you know, I’ve, I used to Crest toothpaste, a little plug there, how did this start?

Dr. Katechia: I think there have been some studies recently that have cast a negative light on fluoride. And if we take a little bit of a deeper dive into those studies, we can see that they’re using concentrations of fluoride that are much, much higher than we are actually recommending at this time. And I think that’s where the misinformation starts.

Carolyn: I read somewhere that like an adult weighing about 150 pounds would have to actually drink 120 gallons of water to have any toxic kind of effect. And all at once, you’d have to drink 120 gallons all at once.

Dr. Gopalakrishna: And if you look at fluoride at the community level, If you look at the track record of what fluoride has done it use, it has significantly reduced the amount of caries by at least 20 to 25%. It has a lot of benefits.

Again, you have to be, when we are looking at fluoride, we have to look for the source of fluoride. Fluoride is in many forms. It could be available in your drinking water. It could be near food, or it could be the food prepared in the fluoride water; and also, how you’re using the fluoride? So of course, if you look at all the recommendations. The pediatric patients, they don’t start using fluoride until they’re able to manage the toothpaste. Like, for example, toothpaste is supposed to be for a local use only, but you’re not supposed to ingest the toothpaste. So we have to weigh in all the sources of fluoride and how it impacts us. So cumulatively, how it impacts us is more important. That has a bigger impact to the outcomes of fluoride.

Chris: Do you find yourself having to sell the idea of fluoride to your patients? Has that started to happen yet? Or what are you prepared to say to patients when they come in with these concerns?

Dr. Katechia: I think when patients do come in with concerns, we always go over what we call a caries risk assessment for a patient. So what we are evaluating is the likelihood of a patient developing a cavity. And we look at different factors. We look at protective factors, like how much fluoride are they having exposure to? We look at clinical factors: Have they had decay? Are they brushing properly? We look at plaque levels when we assess their clinical appearance. And based on that, We make recommendations, including recommendations for fluoride. So that whole assessment is presented to the patient. We talk to them about recommendations based on that clinical assessment that we’ve done and their risk assessment.

Carolyn: Does it change as you get older too? Cause I feel like when I go to the dentist, they still do like a fluoride application, like right before I go.

Dr. Gopalakrishna: So adding to the risk assessment is very important. Given that carries or cavities are driven by multifactorial things. It could be the saliva plays a vital role. And the diet, diet also plays a vital role. So when we’re looking at caries, we are only thinking about microorganisms. I think we have to widen our scope of looking at what causes cavities and is there a perfect storm to create a cavity?

At the same time, your body is trying to produce saliva. Saliva is a very beneficial thing, which has a protective factor. Along with fluoride, it’ll help us to maintain that balance. So let’s say there’s a skew in that balance, where the protective factors are lower and the risk factors are more, let it be the bacteria or any exposure to that, that would lead to the progress of the cavitation.

So it’s good to keep that balance, and we have to make that assessment ahead of time, and there’s a process for that, knowing that it’s a multifactorial thing. So it’s not just because it’s caused by only the bacteria. Along with the bacteria, are there enough factors which are leading to the progress of the cavity?

Chris: If there are people listening who are early on in parenthood — especially from a pediatric dentistry standpoint, maybe their child isn’t old enough to start using toothpaste yet, and there’s kind of like an opportunity to choose a path for the duration of that child’s life as far as oral health care — this would be an opportunity to establish some habits early on that the parent may have stopped thinking about, but now has to think about for the child. So what are the prevailing recommendations for getting your child started on pediatric dental care and how would fluoride fit into that?

Dr. Katechia: Absolutely. So recommendations, we recommend that your child see a dentist as soon as they get their first tooth or by age 1, and that way you can discuss some of these preventive measures. And you also will establish a dental home for your child for ongoing care. At that visit, they may, depending on what they find, recommend that a child will start using toothpaste around the age between 12 and 24 months, and the amount of toothpaste is really important here. You want to use a smear of toothpaste, a tiny little smear, equivalent to a size of a grain of rice — that’s how we describe it, which is a very small amount — twice a day.

As the child gets older, say around the age of 3 or so, you can increase that size to a pea-sized amount with parental-assisted brushing, as well as teaching them to rinse. So, at that age, they can learn how to rinse out the toothpaste and they can use a little bit more.

Around the age of 6 or 7, you can teach them to be a little bit more independent with their brushing. Again, with parental assistance and parental supervision, they can become a little bit more independent with their brushing.

But it’s really important to establish your dental home by the age of 1 or so.

Carolyn: That’s great. That’s good, very good tips. And just one more question about the cosmetic, with that fluorosis, if you do happen to use too much fluoride or whatever, you can get a little. spotting or whatever it’s called?

Dr. Katechia: So you can get modeling, pitting, if you use excessive fluoride. Mild fluorosis is the most common thing that we see. I don’t think in my career, personally, of treating patients, I’ve ever seen a case of severe fluorosis. But I have seen cases of mild fluorosis. And that, it may be just a tiny little white fleck of little whiter enamel. But that’s what we tend to see more often. I don’t think we see so much severe fluorosis.

Carolyn: The benefits are definitely they outweigh the–

Dr. Katechia: Yes, because public water fluoridation is reaching the whole population. And that’s what public health measures are based on, what benefits the population and the community as a whole. And that’s what adding some fluoride to the water has done, benefited the public, people who don’t have access to care, or who may have, you know, disparities in access and other things. And this is a great measure to be able to reach large vasts of community.

Carolyn: So it doesn’t lower your IQ, or cause brain problems or some of the things that the conspiracy theorists are saying?

Dr. Katechia: Not from the studies that are out there that are valid. I think some of these studies that show this, you have to look at the evidence very, very carefully.

Carolyn: Thank you.

Chris: And the overwhelming point is that we have a lot of historic documented scientific proof of the effectiveness of fluoride in the water and fluoride in toothpaste to help combat tooth decay.

Dr. Katechia: Absolutely. We have a lot of evidence, not just in this country, but worldwide. Other countries, if they cannot do water fluoridation, they may add fluoride to the salt, because they may not be able to have access to water. Their water comes from so many different sources and some communities worldwide choose to add it to salt.

I like to think of it as, how we add, say, vitamin D to milk. It’s for the greater good. How we fortify cereals and so on, that’s for the greater good of the public. And that’s how I view fluoride.

Chris: That is Dr. Bina Katechia, interim chair of the Department of Pediatric Dentistry at the UConn School of Dental Medicine. And we also heard today from Dr. Aadarsh Gopalakrishna, who is chair of the Division of General Dentistry at the UConn School of Dental Medicine. Thank you both so much for joining us today.

Dr. Gopalakrishna: Thank you.

Dr. Katechia: You’re welcome. Thank you.

Chris: That is our time for today. For Dr. Gopalakrishna, Dr. Katechia, and Carolyn Pennington, and producer Ethan Giorgetti, I’m Chris DeFrancesco.

Thank you so much for listening to the UConn Health Pulse. Be sure to subscribe so you can catch us next time, and please share with a friend.