Dang! Lost another tooth the other day. Deep in the last century, when I was growing up, there was a lot of sugar about, there was no added fluoride, dental-floss was unheard-of and tooth-brushing was probably pretty cursory. The consequence was that my siblings and I got a headful of dental amalgam to fill the cavities. Dentistry was not very subtle back then, the cavities were reamed out with a pedal-driven augur-bit and the dental amalgam was shovelled in, so that there was often little enough of the original tooth left. All that is now coming home to roost albeit after the better part of half a century of service grinding up my dinner. Every few months for the last few years one or other of the retaining walls of the frozen lakes of amalgam shears off in the middle of a meal and I phone my dentist for a repair job as soon as he can fit me into his busy schedule.
The dentist, let's call him Bill, has a busy schedule because he is good at his job. He's the dentist of choice to the tree-hugging, Birkenstock-wearing (so yesterday, now), home-educating, rice-cake and muesli eating, lactose/gluten/meat intolerant people who make up most of my friends-and-relations. They drive to visit him in Kilkenny, leaving a humongous carbon footprint in their wake, from Waterford, Port Laois, Dublin and probably places further afield which have a wide choice of fang-doctors. If your dentist has a peach-coloured dental chair contact me and we can compare notes.
I like him because he's prepared to treat me for minor works without lidocaine. That gets me through the process ten minutes earlier and I don't spend the rest of the morning chewing my own desensitized tongue. It saves him a little on the consumables bill too. We didn't have the lidocaine option when I were a nipper. A few years ago, I went back to him for a second go on one tooth and he blamed my anti-injection position (and himself) for not doing a thorough job on the cleaning out at the first session a couple of years previously. He'd gone a little easy to spare me the pain; not realising just how well 'ard I am. I've only had one root-canal job and I don't know what all the fuss is about, our chap injected stockholm tar into the cavity as an anti-bacterial agent which I thought was gratifyingly old-style. Like Chips the carpenter doing a bit of dentistry and the odd amputation on a tea-clipper 150 years ago.
Old Bill is widely noted for his rejection of dental amalgam in favour of modern dental composites. The main beef about dental amalgam, which has been doing effective mechanical work for hundreds of years, is its potential toxicity. This is because it is mostly mercury (50%), alloyed with other metals: typically silver (25% ), tin (10%), copper (10%). There is a huge market for the product and lots of suppliers with different formulations and presumably megacorp advertising divisions. There is no doubt that mercury is toxic: Lewis Carroll's Hatter was Mad because of occupational exposure to mercury vapour while making and handling felt. Methylmercury was dumped into the sea from a factory near Minamata in Japan from 1930-1968 and caused a variety of distressing symptoms in those who consumed the fish from the bay. Fish higher up the food chain like tuna and shark are well known for accumulaing and concentrating the mercury as they eat smaller creatures. Japanese people really relish a slice or two of really fresh tuna. I've just read a timely and interesting Tywkiwdbi link suggesting that light-house keepers were prone to go mad and top themselves because of mercury poisoning. The light typically rotates almost frictionlessly on a bath of mercury which needed to be cleaned periodically by straining. So the LHKs were exposed to a gas chamber of mercury vapour for much of their working day.
But the question is whether sufficient mercury is leaching out of my/your amalgam fillings to cause symptoms even remotely approaching the the ataxia, slurred speech, hearing loss, paralysis and death that the fishing families of Minamata experienced. It's hard to do the experiment because you either have grey dental work or you don't and our personalities and behaviour is developing rapidly at the time when most damage is being done to our teeth. Who knows how tall a building I might have been able to leap if I hadn't been handicapped with heavy-metal poisoning. Not much higher than the one I can leap aNNyway is my considered opinion. But I know at least one good friend who, over several time- petrol- and dollar-consuming sessions had all her grey-wear ripped out and replaced with white composite. She says she feels much better since. So it may be, as so often in interesting areas, the interaction terms that are crucial. My genetic makeup and dietary patterns may stabilise my mercury and/or deal effectively with its toxic effects when it escapes. My pal's environmental and genetic mileage may vary.
Now here's the thing, which Bill has never really answered to my satisfaction, modern dental composites are whiter than teeth and have great engineering properties - at least as good as amalgam but . . . they are typically filled with BPA! I'd like someone to do the research to tell me if tiny quantities of mercury are worse for me (and my children) than tiny quantities of a hormone analogue. Your mileage may vary. And yes Old Bill did sort out my tooth. Because the the ennervated root of the tooth was still present, he took a chance and rebuilt my second upper right premolar on that foundation. Like the Hoover dam, it was built up in a few layers each solidified by the UV laser gun that fuses the BPA and the matrix into a solid mass with remarkably tooth-like engineering properties. A crown takes time to install and costs €1000+ but my "just a very large filling" was sorted there-and-then for a lot less money and without lidocaine. Who loses there?