How do Cavity Fillings Work?

Recently (that is to say, between now and when I last blessed you with Information) I made a trip to the dentist to have a cavity filled. Now before you assume that I’m some kind of low life who doesn’t brush his teeth every day, I’m not. I’d like to make it clear that this cavity was discovered at a recent dental appointment, my first in nearly two years (the last of which resulted in the discovery and subsequent treatment of between 3 and 6 cavities - I do not remember the exact number, only that it was the worst spring break ever ever). Before you try to tell me that biannual and not biennial checkups are the norm for educated and insured people in this country I’d like to make it clear that I’m not the kind of person who makes appointments as a measure of preventative physical upkeep, which is why I have not been to a doctor in two years and four months. I’d argue that, factoring in my Coke consumption and general failures at providing myself “good nutrition” on a regular basis, developing only one cavity over the course of two years is a victory in a battle that’s part of a war that only ends when I die or have everything in my mouth replaced with titanium. One or both of these things will happen. Regardless, I am not here to complain to you about how terrible a dental procedure having a cavity filled is, because it’s really a kind of entry-level affair in terms of its brutality and pain. If comfort and convenience were monetary assets then having a cavity filled is like being pick-pocketed (to clarify this metaphor having braces is getting swindled in a long con and having teeth pulled is like being mugged by a guy with pliers and a vendetta). Regardless, I’m sure you will be relieved to know that aside from a half-hour wait in a chair post-lidocaine administration the procedure went off without a hitch, but one part of cavity-filling always made me curious - what the hell is the deal with the UV ray gun?

Maybe it’s best to describe how having a cavity filled works. I assume incorrectly that everyone in this blog’s meager readership has had to deal with situations like this one because I come from a line of people whose teeth immediately begin to turn to dust as soon as they breach the gums. So here’s the short version: the dentist puts some topical anesthetic goo on the gums, then injects (yes with a needle) the gums with a local anesthetic - usually lidocaine - and then everybody waits around for about ten minutes. After you, the patient, are (hopefully) numb in the face-area a drill is administered to your decaying tooth, the purpose of which is to remove all the shittiness that you have let happen because you haven’t been flossing. Usually this doesn’t hurt more than a little bit, though the smell and sensation of ground bone fragments flying into one’s cheeks can be extremely off-putting, and sometimes it does hurt, especially if the rot is far along. Back when I was like seven or eight years old and was having my first batch of cavities dealt with the dentist had two drills, one of which made a low and terrible noise, while the other made a much higher pitched terrible noise. Being a pediatric dentist he liked to personify the drills to his child-patients, and their names were Mr. Bumpy and Mr. Whistle, respectively. This has stuck with me for fourteen years because it is so, so terrifying. I did not have to have parlance with Mr. Bumpy in this most recent procedure, which is always encouraging. Anyway, after the trouble’s been routed a filling is put onto the tooth. This is where I used to get confused. Back in old times, and still occasionally in this modern age, gold or silver were used as the topmost part of the filling. More common now are teeth-colored fillings, made of some kind of science-paste. You see, as best as I can tell the filling material is of some kind of malleable consistency when it’s being shoved into one’s tooth. Then (and this is the science part) the dentist or lowly assistant tells the patient to close their eyes while some kind of futuristic light-gun zaps the newly-placed filling. After this the materials is solid. I’m pretty sure the same stuff is used on braces in some capacity, as I have memories of the orthodontist buzzing my teeth with a similar instrument, but my recollection of those dark times is foggy at best, both from chronological distance and the brain’s natural middle-school-amnesia defense mechanisms. Regardless, this technology has always baffled me. How can exposure to ultraviolet light change something’s consistency so dramatically in a matter of seconds? Well, twenty seconds on Google nets a lot of answers, and apparently I am the only person in the world to be confounded by this kind stuff. According to wikipedia the whole affair is a bunch of chemistry well beyond the scope of anything I’m willing to understand, but the fact remains that it’s very cool. I am happy to have solved this mystery that had been nagging at me. I am glad to have this Information.