the importance of saliva
This clear fluid that is usually taken for granted has almost magical qualities when it comes to teeth. Without it, or enough of it, our teeth suffer tremendously. Not only does saliva make it easy to swallow and begin digesting food right in our mouths, but it has special neutralising, remineralising and antibacterial qualities. For instance, when plaque or acid attacks a tooth surface, calcium and phosphate in saliva can actually repair early damage. This can mean the difference between having normal healthy teeth or teeth that are decayed or eroded.
These days with fluoride in the Sydney water supply, most people have very little decay. We might get a few cavities as a child or teenager but, when we enter adulthood, new decay should be relatively rare. If you are an adult and have been getting new decay, there will usually be a reason for it, and the reason will probably not be related to your teeth.
This thinking has changed the way dentists operate and a lot of time is spent these days finding out about any medical issues you might have or medications you might be taking, as many of these can dry or alter your saliva. Over 400 prescribed medications; antihypertensives, antidepressants, anticonvulsants, asthma medications (to name a few) and many over the counter medications list dry mouth as a side effect. Even personal lifestyle choices, like whether you smoke cigarettes or take recreational drugs, or how much alcohol or coffee you drink, can have a profound effect. While the effects of salivary dysfunction can be extreme and cause even young people to lose teeth, they are usually hidden and most people do not even know they have a problem. Your dentist has to be a bit of a Sherlock Holmes to elicit the information that gives them a clue to the reason you might be getting tooth decay or your teeth are eroded.
Erosion is a relatively new issue in dentistry. It has been somewhat overlooked in the past because dentists didn’t really understand the role played by saliva. Unfortunately it’s becoming a very common problem, maybe even more common and important than decay.
In the extreme, it can dissolve teeth right to the gum line, even by age 21! It sometimes happens to otherwise healthy young adults who just drink too much of certain soft drinks. These young people might be leading healthy active lives and simply not drinking enough water, especially in the hot summer months when body dehydration means a drying up of the saliva. Many popular drinks contain caffeine which also has a drying effect. If people rehydrate with a drink containing caffeine, they can multiply the problem, especially if they become addicted to it. It’s always good to read the label to determine the caffeine content. Unfortunately the pH (acid) content is not listed on the label and acidic foods can do great damage, corroding the tooth surface. There are a number of acidic food sources that if we have too much can do damage (cola drinks, pineapple and lemon juices, vinegar, the skins of citrus fruits, chewable vitamin C tablets, to name a few). People with eating disorders or binge drinkers are at risk from their own stomach acid when they vomit (you should never brush your teeth immediately after vomiting – water gets rid of the taste very effectively and your saliva will repair a lot of the damage if you just leave it alone). Even something as simple as heartburn can mean an underlying acid problem. Your saliva is your best defence. Too much acid and not enough saliva is a very dangerous combination.
People without teeth who wear dentures shouldn’t think they are immune from the protective role of saliva. The skin inside the mouth, the oral mucosa, needs the lubricating effect of saliva to stay healthy. Imagine if your mouth is dry having something hard like a denture rub back and forth against it all day long. It’s obviously important that the denture doesn’t move but its also important that everything possible is done to keep the mouth moist. Ulcers can be very painful and gum shrinkage makes for even less denture support. Fortunately there are some sprays that can moisten the mouth, but generally it’s finding and changing the causes of the dry mouth that matters. Some diseases are very debilitating in this regard and for the people who suffer them, dental implants are a wonderful way to stabilise or replace moving dentures.
The ground-breaking research in the last few years has taught dentists the relationship between medical health, lifestyle and teeth, and showed them how to offer their patients simple tests to find out whether they have salivary dysfunction. It does take some time to do a good medical and lifestyle interview but it only takes a few minutes to sit quietly and produce some saliva for the dentist to find out about your resting flow rate and neutralising (or buffering) capacity. Once it’s known something is wrong, a diagnosis can be made and steps can be taken to reverse or reduce the problem.