Misperceptions on saliva
At home experiment
Indicators of basic saliva and good quality saliva
How to make good quality saliva
Protein and Arginine
Michelle Strange: A Tale of Two Hygienists presents this week’s TIPisode: Quick and easy tips to keep you up to date and presented by the experts in the profession. Now, get ready for your unofficial TIPisode.
Dr. Brian Novy: I am Dr. Brian Novy, and I am the Chief Dental Officer at the Alliance Dental Center in Quincy, Massachusetts, which is the incubator office for the Massachusetts Public Employees Fund. I practice clinical dentistry four to six days a week and teach at a couple different dental schools and spend my spare time lecturing at different dental meetings around the world.
Today, I would love to talk about saliva, my favorite topic in the whole wide world because what I’ve found as I travel around and as I teach cariology to dentists and dental hygienists and dental assistants and everyone in the dental ecosystem, there seems to be this misconception or misperception that the amount of saliva in your mouth is actually equated to how healthy your mouth is.
We tend to think that if you have a lot of saliva, you probably have a really healthy mouth. So, in a lot of caries risk assessment activities, people tend to ask the question “Does your mouth appear dry? Does it feel dry?” When in fact you can have a little bit of really good saliva, or you can have a lot of really bad saliva. And point in fact is the reality that every dentist has prepped a crown and not been able to produce a good temporary and not been able to take a good impression because that tooth is being bathed in so much saliva.
So, if that saliva is really good, quality saliva, why would that patient need a crown to be done in the first place? That saliva should have been protecting that tooth from getting a crown. So it’s not just about the quantity of saliva. It’s about the quality of saliva. And a lot of people think that “Well, if you don’t have saliva, maybe we could just stimulate more saliva because if you stimulate saliva, then that’s going to be good, quality saliva.” And I say, “No, no. Just because you stimulate saliva doesn’t mean you’re going to actually stimulate good, quality saliva.” And, in fact, if your patient has Sjogren’s syndrome and you stimulate saliva, you could actually stimulate really bad saliva that just even furthers the caries process.
So this TIPisode I really want to talk about saliva because it’s such an underappreciated bodily fluid that is, in my opinion, the most diagnostic fluid of the human body. But, as I lead into this TIPisode, as you’re listening to this, it would be great if you could wander around your house or around the lunchroom in your office. Go find yourself some source of acid like lemon juice or lime juice or vinegar or even Coke or 7UP. Those would be great sources of acid to show you what I want you to feel in your own mouth. But, also, go find yourself some salt.
So you’re looking for a source of acid and some salt. You could use some salty nuts if you want like some salty sunflower seeds. Those would be great. But you could just have a little bit of table salt too. And then later on in the TIPisode we’ll do a hands-on activity.
So what I’d like to — what I want the audience to actually understand is that just because you have saliva doesn’t mean there isn’t something to improve in the saliva. And, very often when you look in a patient’s mouth, you can figure out is the quality of the saliva really good, or is the quality of the saliva poor, and can it be improved somehow?
So, if you look into a patient’s mouth and you see a lot of calculus everywhere, oddly enough that’s a really good indication that the patient has really good, quality saliva. It means they have a high buffering capacity. They have a lot of ions in their saliva, and it’s basic, and that’s why it’s actually mineralizing the plaque. It’s turning the plaque hard and calcifying it because there’s so many excess ions in the saliva, and it’s basic.
In the opposite of that extreme is the patient who doesn’t produce any calculus at all on their teeth. You look in their mouth, and you say, “Oh, my gosh. You must be a really good brusher. There’s no tartar on your teeth.” Well, actually, that’s an indication the patient’s saliva is so acidic it’s breaking down the calculus on their teeth, and it’s demineralizing the teeth, and it’s actually nurturing the growth of aciduric bacteria, the bacteria that cause tooth decay, which then in turn grown acidogenic bacteria that like to live in acids.
So really good, quality saliva is basic. It’s at a pH above 6.8. Even better, it’d be above 7. When it gets above 7.2, you start to form calculus like stalagmites and stalactites on the teeth, and that’s because you have a protein in your saliva which is there by design to prevent you from forming calculus.
So you have a protein in your saliva called statherin which inhibits the primary and secondary precipitation of calcium from your saliva. So, if you have statherin in your saliva, which is only there and is only functional between the pH of 6.8 to 7.2 — so, if the pH of your saliva goes above 7.2, statherin doesn’t fold properly, and then it can’t prevent calculus from forming on your teeth. So, when the pH of your saliva stays above 7.2, statherin doesn’t fold properly, and you form calculus on your teeth like crazy.
And, oddly enough — well, not oddly enough — and we usually see that in patients who have kidney disease because when you’re kidneys stop functioning, your salivary glands turn into surrogate kidneys and actually pull urea from your bloodstream, filter it into your mouth, and it raises the pH of your mouth so high you don’t get tooth decay anymore. You form calculus like crazy.
And we see this in patients, and we go, “Oh, my gosh. Doesn’t this patient brush their teeth?” Well, they could brush every single day really, really well and they’re still going to form calculus because their saliva is so basic. And that one protein which is there to stop calculus from forming, that one protein doesn’t fold, calculus forms like crazy, and we think, “Oh, this patient just doesn’t brush,” when in fact it’s all about the chemistry of their saliva.
So the question really becomes how do you identify that a patient has really good, quality saliva? Well, usually they have a little bit of tartar on their teeth, they have a little bit of calculus on their teeth. That’s a good indication that their mouth — or their saliva’s usually basic, and usually they’re low caries risk. You notice they don’t have interproximal lesions, and if they do have any exposed root surfaces, they’re hard, and they’re glossy, and they’re nice and smooth. If they start to demineralize, really good indication that their saliva is probably fairly acidic.
So what makes good saliva is the fact that you have an elevated pH of 6.8, you have really good ionic concentration in your saliva — so you’ve got calcium, and you’ve got some phosphate, and you have a lot of bicarbonate in there as well, which keeps the pH elevated — but most importantly in really good saliva is the abundance of proteins. And so, if you have a ton of protein in your saliva, it’s probably very good, quality saliva rich in calcium and phosphate at a basic pH.
In modern cariology, there’s a lot of talk about how do we actually use protein in the saliva to drive oral health because we know that the good bacteria that grow on your teeth, they consume proteins from your saliva, and when they eat the proteins in your saliva, they poop out urea and ammonia as a byproduct of their metabolism, and they shift the biofilm pH to something that’s more basic, and they create a good, basic biofilm on your teeth, which can actually remineralize early caries lesions.
So you can identify good, quality saliva by looking for a little bit of calculus on your patient’s teeth, not seeing any sort of demineralization in their mouth, and that you have an adequate amount of that saliva in your mouth. So those are the three things I’m looking for when I do a patient exam.
You also can notice it clinically. If you ever have noticed that when you take fluoride varnish and you’re wiping fluoride varnish on a patient’s teeth and sometimes you don’t get them quite dry and your brush goes through the saliva a little bit and you notice a booger forming on the end of your brush and you’re trying to get — you’re thinking, “Oh, well it’s okay. I’ll just wipe this on the teeth,” but you can’t get it to stick to the teeth because it’s sticking more to the brush and you’re wiping this goo — you’re pulling this goober throughout the whole patient’s mouth and you’re like “Just get off the brush,” that’s a really good indication that patient’s saliva is so rich in calcium and phosphate, the chemical reaction that it’s having on the brush creating that booger is what you wanted to happen on the tooth. And what it means is that you’re applying fluoride varnish incorrectly in that patient’s mouth. That means you’re doing it wrong. You need to get all the saliva out of there. Get the teeth dry. Get a new brush. Get some new fluoride varnish because you cannot stop that chemical reaction that’s happening on the end of that fluoride varnish brush.
So I say any time you notice that booger forming on your fluoride varnish brush, it means you’re doing something wrong, or it also means the patient has really good, quality saliva.
But the question really becomes how do you make good, quality saliva? So, if you want to actually get a feel, no pun — you’re going to get a mouth feel for quality saliva. So, if you take that acid that you’ve found, whether it’s lemon juice or Coke or 7UP or vinegar — I don’t know why you’d have vinegar in your dental office. But, if you have vinegar for your fish and chips that you’re eating at lunch time, take your finger and put it — and if you’re not — if you don’t have hands-on stuff at home to do this with you right now, just picture this in your mind, and you’ll probably stop — you’ll start salivating anyway because that’s what we do. We salivate when we think about salivating.
But, if you dip your finger in your acid — your lemon juice or your vinegar or something — and taste it, it’s sour, and you notice that immediately you start to produce a little bit of saliva. Well, okay. So just make a note of how much saliva do you feel like you produced right then and there. You produced a little bit. Your mouth tasted something sour, and your body reacted by stimulating some saliva to try to neutralize that acid.
Well, now, take your salt. And what people don’t realize is that when you put salt on your tongue, the sodium ion is actually a potent saliva stimulant. And more so than being a potent saliva stimulant, it actually sends a signal to your brain which sends a signal to your salivary glands to actually increase protein synthesis, and it’s making you generate a lot more protein.
You’ll notice that when you put acid in your mouth, you produce a little bit of saliva. When you put salt in your mouth, you produce a lot of saliva, and it feels thick, it feels luscious, it feels much more slippery, and there’s a lot more of it. That’s because you have systemically, now, caused your salivary glands to change what they’re producing, and you’ve told them “produce higher quality saliva.”
When you put acid in your mouth, your body is responding just to neutralize that acid and put out some saliva with some bicarbonate in it to neutralize the acid. But, when you put salt on your tongue, it increases protein synthesis in your salivary glands, and then it dumps all that extra protein into your saliva. And, since I’ve already explained how protein works in your biofilm, you can now rest assured that you’re actually feeding the good bacteria in your mouth, that extra protein in your saliva, and you’re nurturing the growth of the good bacteria in your mouth not just by stimulating saliva but by stimulating really good, high-quality, protein-rich saliva.
And, if you want to increase the amount of protein in your saliva anyway, it’s really simple. Just increase the amount of protein in your diet. More protein in the diet means more protein in the saliva. And which foods are high in the best protein for our saliva? Spinach, soy, seafood, and nuts. Each one of those foods is rich in arginine, and arginine is an amino acid that when we have more arginine in the saliva, it drives caries resistance because we’ve got some research which shows us that if you increase the concentration of free arginine in saliva, you decrease the patient’s caries risk.
And so that is my hands-on TIPisode for how to improve the quality of your own saliva, understand the quality of your patient’s saliva, and actually use it to stimulate some changes in your patient’s diet, which could lead to increased quality of saliva for days on end. And you don’t need to think about acids anymore. You can just think about salt and stimulate some really good saliva.
Well, this has been Dr. Brian Novy. Thank you for listening to this week’s TIPisode. If you want more of my harebrained facts about how to generate a healthy mouth, you can check out my website, www.whollymolar.com, and “whollymolar” is spelled W-H-O-L-L-Y-M-O-L-A-R. Or you can follow me on Twitter @BrianNovy1 because BrianNovy was already taken.
And thank you very much to GC America for making this TIPisode happen.
Michelle Strange: We hope you enjoyed this week’s TIPisode. Be sure to reach out to our guest experts and let them know how helpful their tips were. Follow A Tale of Two Hygienists on Facebook, Instagram, and head over to ataleoftwohygienists.com and subscribe to our newsletter. You can also email us at firstname.lastname@example.org, and keep listening for more awesome content from your unofficial dental hygiene podcast.