Tooth enamel is the hardest substance in the human body. Each tooth is innervated and incredibly sensitive. But despite teeth being the living stone of our bodies, cavities are a common phenomenon. Many people get them from poor hygiene, but others get them from several reasons as well. In fact, they're the most common chronic disease in children and teens. And according to the CDC, nine out of ten adults have some form of tooth decay. Now, this doesn't always mean cavities, but it can mean demineralization that weaken the enamel and drastically increase the chances of getting cavities as age increases. And so today we'll go through several aspects of dental cavities. Including how they form, why people get cavities, how cavities are treated, and finally, how they are prevented. So firstly, a cavity forms in several steps in varying levels of severity. This can occur anywhere on a tooth, but the most common areas of decay are in between the teeth, as well as on the occlusal biting surface. And so the first initiating step of a cavity formation is bacteria. A common bacteria that can cause cavities is Streptococcus mutans. Now what this bacteria does is it consumes the sugar that we consume and will release acid. Now this acid will demineralize the tooth by stripping away the calcium phosphate. And so, as this erosion continues, we get penetration into the enamel and this causes a cavity. And if this isn't treated promptly, then the bacteria and acid will continue to penetrate deeper into the tooth, into the soft dentin. Now the problem with this is that dentin doesn't have that hard barrier that enamel does. And so once a cavity reaches this level, it proceeds quite quickly. And the last step of a cavity is infection of the pulp, and this is the inner nerves of the tooth, and it can be quite painful. So now that we know a little bit more about the steps of a cavity, I'd like to talk a little bit about how each cavity is treated. Now, treatment of cavities will vary depending on what stage of demineralization or decay a tooth is at. And so at the smallest level, a sealant is something that treats demineralization. And a sealant is essentially a small filling that covers the surface of the tooth. And the good thing about this is that it only requires a little roughening of the surface to allow the sealant to bind. And it doesn't require any anesthetic. But perhaps something that we are more familiar with, are fillings. Now, fillings treat cavities that have penetrated into the enamel as well as into the dentin. And so there are two types of fillings that are commonly used today. The first one is composite filling. Composite is a resin-based material that matches tooth color quite well, but the bad thing about it is that it only lasts five to ten years. However, composite filling is quite flexible, and by flexible, I mean that it can bend with the different pressures of the tooth. On the flip side, amalgam is the second type of filling that isn't quite as commonly used today anymore. An amalgam is essentially a metal alloy, and it lasts several years, but it's incredibly unappealing. It's that silver filling that appears in some teeth. And because this metal alloy is so hard, it doesn't allow for flexibility in the tooth. And what can happen is after several years of having an amalgam filling, cracks in the teeth can form due to this hard, inflexible material inside the tooth. Finally, after a filling, at the very deepest stage of a cavity, when the bacteria have infected the pulp, a cavity won't treat the problem. And so what happens is a root canal or extraction might be necessary to prevent further infection. So we can see that treatment of cavities is quite variable. But additionally, there are several reasons why people get cavities, and these are quite diverse as well. This can be due to both oral hygiene, as well as genetic influences. So I'd like to talk a little bit more about oral hygiene. Well, most of us know that brushing and flossing are incredibly important in maintaining oral health, and this is due to plaque. And so, if we don't brush and floss multiple times, then what can happen is plague starts to form and tartar builds up from this plague, and this can cause the inflammation of the gums or gingivitis. Now if this isn't treated, then the gums will begin to recede and expose the root of the tooth. Now the root of the tooth doesn't have this hard first layer of enamel protecting it. And so, what will happen is bacteria will tend to form cavities on the root surface of the tooth. Now another component to oral hygiene is what foods we eat. So for people who eat a lot of acidic foods, they're actually aiding in the direct erosion of their enamel. And likewise, people who eat a lot of sugary foods or foods with a lot of carbohydrates, will aide in providing food for the bacteria that will in turn produce the acid. And so, for people who eat a lot of acidic and sugary foods, they are quite prone to cavities. Now, besides some oral hygiene, there's also a genetic factor to cavities. And so, the biggest component to genetics is how conducive our mouths are to different bacterial strains. So, some people may not have a conducive environment in their mouths for a bacteria like Streptococcus mutans. And so, for these people, they can eat as much sugar as they want, as many carbohydrates as they want, but they won't have the bacteria that will consume that and release that acid. And so they won't be quite as prone to cavities. The second component to genetics is salivary production. So saliva acts as a great buffer. And what this means is that when we consume foods that are low in pH, so very acidic, or high pH, which are very basic, then saliva acts as a buffer to neutralize these foods and keep our mouth very neutral. Now, for people who don't produce a lot of saliva, they can't neutralize these acids as well. And so therefore, they'll have more erosion from the acid and be more prone to cavities. So, because there is so many reasons why people get cavities, there are also several methods of prevention that have been proven quite effective outside of just oral hygiene and biannual cleanings. The first one of these methods is fluoridation. Fluoride is a great substance that will protect the enamel by making it harder for bacteria, the acid, to strip away the calcium phosphate. And so, many cities have actually mandated that all their water supplies be fluoridated, and this has drastically decreased the amount of cavities seen in children and teens. In a similar manner, people who are quite prone to cavities are often prescribed prescription toothpaste which has higher levels of fluoride, and so can directly aid in preventing the stripping away of enamel as well. A second method of prevention is simply limiting the carbohydrates and acidic foods that we intake to both directly and indirectly prevent the erosion. When we can't limit our carbohydrate and acid intake, brushing and drinking water right after eating these foods can help in neutralizing the pH in our mouths. Now, to talk about genetics, well, it's more difficult to treat these problems, but a great product that has been released are Biotin products. Now, Biotin products are a series of products that will actually increase salivary flow. And so, it's been quite helpful for people with dry mouths in increasing their salivary production to increase the buffering capacities of their mouths. So, today we've talked about how cavities form, how they're treated, why people get cavities, and finally, how cavities are prevented. Now, we can see that the mouth is an extraordinarily complex organ, and every tooth is equally complex as well. So while the process of cavitation and the treatment are fairly consistent, the causes of decay can vary tremendously, and as a result, preventive measures vary as well. [MUSIC]
