Understanding Saliva’s Role in Oral Health

The sublingual papillae, those two constant suppliers of saliva, are situated right behind our lower front teeth, which are particularly susceptible to the build-up of tartar. This is because there are substances in our saliva that contain calcium, which are actually only intent on making our teeth harder. But if a tooth is constantly bombarded with calcium, it can be a case of too much of a good thing. Tiny molecules floating innocently by are caught up and “‘fossilised’ without so much as a by-your-leave. The problem is not the tartar itself, but the fact that it has such a rough surface, affording a much better foothold for bacteria that cause tooth decay and gum disease than smooth, clean tooth enamel.

Saliva is, basically, filtered blood. The salivary glands sieve the blood, keeping back the red blood cells, which are needed in our arteries, not our mouth. But calcium, hormones, and some products of our immune system enter the saliva from the blood. That explains why each person’s saliva is slightly different. In fact, saliva analysis can be used to test for diseases of the immune system, or for certain hormones. The salivary glands can also add extra substances, including those calcium-containing compounds, and even natural painkillers.

Our saliva contains one painkiller that is stronger than morphine. It is called opiorphin, and was only discovered in 2006. Of course, we produce only small amounts of this compound otherwise we would be spaced out on our own spit all the time. But even a small amount has a noticeable effect, since our mouth is such a sensitive thing. It contains more nerve endings than almost anywhere else in the human body – even the tiniest strawberry seed can drive us crazy if it gets stuck somewhere; we feel every grain of sand in a badly washed salad. A teeny little sore, which we would not even notice if it were on our elbow, hurts like hell and feels monstrously big in our mouth.

When we chew, we produce more saliva, and with it more of such analgesic substances, which explains why a sore throat often feels better after a meal, and even minor sores in the oral cavity hurt less. It doesn’t have to be a meal – even chewing gum provides us with a dose of our oral anodyne.

Saliva protects the oral cavity not only from too much pain, but also from too many bad bacteria. That’s the job of mucins, for example. Mucins are proteins that form the main constituent of mucous. They help provide hours of fascination and fun for young children who have just found out they can blow bubbles with their own spit. A more useful function is their ability to envelop our teeth and gums in a protective mucin net. We shoot them out of our salivary papillae like Spiderman shoots webs from his wrists. These microscopic nets can catch bacteria before they have a chance to harm us. While the bad bacteria are caught in the net, substances in our saliva can kill them off.

When we are asleep we produce very little saliva. That’s good news for those who tend to drool into their pillow – if they produced the full daytime quota of one to one-and-a-half liters during the night, too, the results would not be particularly pleasant. The fact that we produce so little saliva at night explains why many people have bad breath or a sore throat in the morning, Eight hours of scarce salivation mean one thing for the microbes in our mouth: party time! Brazen bacteria are no longer kept in check, and the mucous membranes in our mouth and throat miss their sprinkler system.

Brushing at bedtime reduces the number of bacteria in your mouth, leaving fewer partygoers for the all-night bash. Brushing in the morning is like cleaning up after the party the night before. Luckily, our salivary glands wake up at the same time we do in the morning, and start production straight away. Munching on our first piece of toast or performing our morning dental-hygiene duties adds extra stimulation for salivation, and this washes away the nocturnal microbes or transports them down into our stomach, where our gastric juices finally finish them off.

Those who suffer from bad breath during the day may have not managed to remove enough musty-smelling bacteria. Those cunning little critters love to hide out under the newly formed mucin net where the anti-bacterial substances in our saliva cannot get to them. A tongue scraper can help here, but so can chewing gum. It helps stimulate saliva production to swill away those mucin hide-outs. If none of this helps, there is another place where the causes of bad breath can lurk. But more of that later, after we have found out about the second secret place in our mouths.

Source – Gut: The Inside Story of Our Body’s Most Underrated Organ by Giulia Enders, Jill Enders (Illustrator)

Goodreads – https://www.goodreads.com/book/show/23013953-gut