How to Fix Your Own Teeth (with stuff you buy from Bunnings)

Sometimes I wish I’d been a dentist.

When I’m paying my bill, that is! Boy it’s expensive!

Now, I’m always looking for ways to save myself money using my chemical knowledge (which led me to design my own way to make biodiesel, but that’s another story), and now out of necessity I’ve turned my thoughts to dentistry.

This wasn’t planned of course, but the other day I was munching on a pizza with a particularly crusty crust when I felt an almighty CRUNCH as I bit down on it. When I fished the offending item out of my mouth it was a substantial part of one of my teeth.

The tooth in question has an almighty amalgam filling in the middle of it, and so the bits around the edge don’t have a lot of mechanical support, and hence the failure.

So now I had this tooth fragment sitting in my desk as I contemplated my options. The first option of course was the dentist. From previous experience I know what she’d tell me. First it’d need a temporary repair, and then she’d take a mould, and I’d I’d have to come back for a crown.

This of course would involve a couple of thousand dollars (I think – I had one done a few years back). Since this is more than I normally spend on cars that I buy, I figured there had to be other options.

As I thought about it, it occurred to me that there was indeed another option. When we get our teeth repaired these days, amalgams are no longer used. Rather, they have been replaced by UV-curing (epoxy) polymers. They put some white stuff in your mouth, zap it with a UV light for 30 seconds or so, and Bob’s your uncle.

So all I need to do to fix my broken tooth is to find a rapidly curing polymer that can be moulded for long enough for me to hold it in place while it sets. Then it occurred to me that I had just such a product in my garage. I had bought it a while ago because I thought it looked like a useful product, although I didn’t have a use for it at the time:

Here’s how it works.

Have I mentioned that I’m not a dentist? Not sure if I’ve mentioned that yet.

Now, to fix my tooth, I had to prepare the surface correctly, as with any adhesive. This of course was a little tricky, as it was inside my mouth, and moisture was obviously going to be a challenge.

Here’s how I did it:

1. I removed any bacteria (and food) from the surface to be repaired. Anaerobic bacteria are responsible for tooth decay (they produce the lactic acid that dissolves the calcium phosphate from which your teeth are made). This was easily done with a Listerine rinse.

2. I dried the surface to be repaired. For this, I got a cotton bud and soaked it in metho. Then I just rubbed it over the surface liberally.

3. I then repeated with acetone. I was careful with this – if you get it on your tongue the sensation is rather unpleasant.

The area was now (or should have been) dry. An alternative approach would have been a gentle stream of compressed air (if I had a compressor handy), as this is what dentists use.

4. I mixed the epoxy (while holding my mouth open). Took about 30 seconds to get a consistent mix.

5. I pressed it into my tooth, and held it there with firm pressure, attempting to mould it to the approximate contour of my teeth. I poked the unused portion occasionally to get a feel for when it set (about 3 min). Then I just gently removed my fingers from the epoxy and it stayed behind.

When I did this I immediately felt the roughness of the material in my mouth. But it seemed to work, so I was happy, and I figured I’d just let it set fully and then sand it smooth the next day.

But the next day when I woke up it felt smoother. Over the next few days it seemed to smooth out naturally, and a week later it now seems to have conformed to the contours of my teeth naturally.

I haven’t been game to give it any serious bite work, but it’s OK for mushy chewing. And it’s perfectly safe chemically, as the product is certified for use with drinking materials.

And now a disclaimer or two – this technique should certainly not be used to repair a decayed tooth.

Here’s why.

Decay is caused by lactic acid, which gradually dissolves the calcium phosphate from which your teeth are made. The lactic acid comes from the breakdown of sugars, caused by anaerobic bacteria, which inhabit plaque. At the microscopic level, therefore, the cavity is a very irregular shape, with little channels and pores in which the bacteria sit, producing the lactic acid. This is why dentists drill before filling – they need to completely remove the decayed area, thus creating a smooth mechanical surface to which the filling can adhere.

If you just plonk an epoxy on top, the bacteria are free to continue their decaying process, and probably at a greater rate, as the lactic acid is not now being washed away.

So I would only use this technique, as I have, for a situation where the failure was purely mechanical, and I was attaching the epoxy to a clean, undecayed surface.

Once again, I am not a dentist, so I’m not recommending this to anyone – I’m just telling you what I did.

Just thought I’d mention that….

One other thing – chemical safety. Is this stuff safe to put in your mouth? As it happens, it is – if you look on the documentation for this stuff it says that it’s safe to use on drinking utensils. The reason is that it’s a thermoset polymer, which means that the polymerisation process is irreversible – it sets into an inert solid that has no chemical toxicity whatever.

 

Is Water Fluoridation Safe?

The short answer is yes, it is, but it’s easy to understand why some people think it isn’t.

When we look at chemical toxicity, we need to understand that there are several different classes.

Firstly, there are chemicals for which any level of exposure is undesirable, as with sufficient exposure over time they will have an effect on our health, possibly with lethal outcomes. In this category we have asbestos, lead, and any of the tars and other combustion products in cigarettes.

There are other chemicals, however, which although toxic in higher concentrations, are either completely harmless, or even beneficial at low levels. In this category we have most transition metals such as copper, zinc and iron.

And fluoride.

But the trouble is that this is not obvious if you look at the data, and fluoride is a case in point. If you look at the MSDS for sodium fluoride you find that it is an S7 poison – the highest category. Little wonder that some people are leery about having it in their water.

So what does fluoride do in your body?

Mostly, it reacts with your bones. In this regard it is unusual, as most other toxins attack your organs somehow. But the fluoride attacks your bones. This is why in Breaking Bad it is the chemical of choice for disposing of bodies…..

So if you are exposed to enough of it to be harmful it causes horrible internal burns which are very difficult to treat. Whenever I have had to handle hydrofluoric acid (it’s used to make industrial strength brick cleaner) I’ve gone the full monty in terms of protective gear.

But in water it’s nowhere near this strength. The fluoridating agent in municipal waters is fluorosilicic acid, a by-product of aluminium production, and it gives a level of fluoridation of about 2mg/L.

At this concentration it is too low to be harmful – no matter how much water you drink – but it still reacts with your teeth. I don’t think anyone quite understands the mechanism, but it would be some sort of inorganic composite where the fluoride combines with the calcium phosphate (that your teeth are made of) to produce some sort of calcium fluorophosphate, that is in some way chemically resistant to the chemical decay process (caused by lactic acid that is made by anaerobic bacteria).

And this has certainly been confirmed by every study in this area – so you may drink municipal water – and use toothpaste, with absolute confidence that your teeth are being protected.

An Alternative Shaving Cream

So you need to have a shave but you’re out of shaving cream?

What do you do?

Well, you have a couple of options. The main function of shaving cream is to lubricate your face so that the blade can glide across your skin without shaving.

Conventional shaving creams are made up of essentially foaming surfactants and lubricating oils such as lanolin (a natural lubricating compound that comes from wool). The purpose of the foam is essentially to give it some body so that it occupies some volume on your face.

The first option you have is ordinary old soap, with a shaving brush and cup (yes, they still exist). You put the soap in the cup with some hot water, and whip it up to a lather with the shaving brush, which you then use to brush it on your face.

Soap is of course slippery, so it acts as a good lubricant, although with time it of course it has the effect of drying your skin. This is perhaps why our grandfathers had skin that looked like leather.

But there’s a better option. There is a bathroom product that is remarkably similar to shaving gel – toothpaste gel.

These products come in an aluminium can and are dispensed under low pressure when you press the actuator. It’s a thick gel, and when you rub it into your skin it readily foams up into a thick lather.

The thick gel is generated by PEGs (polyethylene glycols) and forms a highly effective smoothing raft over the skin. The additives are different, of course – the shaving foam contains lanolins, whereas toothpaste contains things for your teeth – fluorides, silicas and menthols.

But none of that matters – the toothpaste does a great job, and feels no different to shaving gel.

With one exception. The menthol in the toothpaste has a very bracing effect on your skin, almost to the effect of stinging – rather like the effect of aftershave actually. It’s a pleasant sensation, however, and leaves your skin feeling very refreshed.

 

Book Extract #12: Toothpastes

Toothpastes are a little like dishwashing detergents in that there is very little difference between brands, and our choice of product is determined exclusively by how well they have been marketed.

Toothpastes are essentially abrasives in a gum or glycol base with some surfactants, colouring agents, flavouring and fluoride added.  So all they are designed to do is scrub plaque and embedded food off your teeth, impart some fluoride, and make your mouth feel fresh.

And they are mostly all the same (with one exception).  There is very little difference in composition between the generic brands and the top of the line “whitening” toothpastes.

But this hasn’t always been the case.  Several years ago the “whitening” toothpastes were premium products that actually did contain a whitening agent – peroxide.  They also contained sodium bicarbonate which is an effective defence against tooth decay.

The cause of tooth decay is not well understood generally.  We hear that it is caused by “acids” and are told to avoid acidic foods. This is only partially right.  Our teeth are essentially a mineral called hydroxyapatite, which is composed of calcium phosphate.  This is a chemically stable compound and is not easily dissolved by acids, certainly not any acids in the foods that we eat.

So when we are told to avoid acidic foods like orange juice (citric acid) or Coca-Cola (phosphoric acid) or soft drinks in general (carbonic acid), we are being misled, as none of these acids are strong enough to dissolve our teeth in the few seconds that they are in contact with them.

Here’s what happens.

When we consume sugar (which is the real enemy of teeth) it combines with proteins to form glycoproteins, which is plaque.  The plaque has a strong affinity for our teeth and coats them easily.  What happens then is that the glycoproteins are degraded by anaerobic bacteria, in a process that is remarkably similar to what happens in our muscles when we exercise.

Since the plaque has coated our teeth very effectively, and is essentially nonporous, it’s an anaerobic (no oxygen) environment.  What happens then is that anaerobic bacteria degrade the glycoproteins to form lactic acid, a relatively strong organic acid.  But since it forms at the very surface of our teeth, and is held in place by the plaque, it begins dissolving the calcium phosphate that your teeth are made out of.

So there is certainly a case for having a mildly alkaline component in toothpastes that will neutralise this effect, and sodium bicarbonate fits the bill beautifully.

Incidentally, desensitising toothpastes seek to reverse this process.  They do this by including calcium and phosphate in their formula, the idea being that they will combine to form the hydroxyapatite that your teeth are made out of and rebuild the surface (covering the sensitive part that has been exposed).

In terms of whitening, peroxide is the perfect whitening agent for teeth.  Mostly present as sodium percarbonate ( which as we have seen in section 5.2 is also a laundry bleach), they get away with calling it a peroxide as it is alternately referred to as sodium carbonate peroxide, due to an unusual molecular formula which is essentially three hydrogen peroxide molecules stuck onto a sodium carbonate molecule (2Na2CO3.3H2O2).

There was a time when each off the major toothpaste manufacturers had a whitening toothpaste on the market with this formula. Several years ago, that all changed, and although they were still called “whitening” toothpastes, the baking soda and peroxide disappeared from the formulas.  This was no doubt a decision made at a marketing level, in the hope that they could make the products cheaper, and make more profit, and that no one would notice.

In other words, they are treating you like mugs.

Unfortunately, however, someone did notice – in this case, Choice Magazine, who were the first to bring it to public attention.  So now the great con has been exposed – the toothpastes with fancy packaging that include glittering letters that claim to be whitening toothpastes will do no more to whiten your teeth than the generic Coles and Woolworths brands.

And it’s only Australia.  If you Google “whitening toothpaste” you will see that the products containing bicarb and peroxide are still sold overseas.  It’s only the Australian market where they think we are dumb enough not to notice.  In fact it is the marketing people who are the dumb ones, as their attempt to con the Australian public has now been exposed.

There is one exception to this, however – an American brand called Arm & Hammer.  Curiously, this well recognised brand in the USA made their name selling products based on bicarb soda and washing soda.  Toothpaste was therefore a logical extension of their brand name, and the addition of the sodium percarbonate makes it the only serious whitening toothpaste on the market.

The Great Whitening Toothpaste Con

Last month CHOICE lifted the lid on whitening toothpastes.

They pointed out, quite rightly, that the ingredients in so-called “whitening toothpastes were no different from the ingredients in ordinary toothpastes.

This took me a little by surprise, for the simple reason that the “whitening” toothpastes did indeed used to contain whitening agents – notably hydrogen peroxide.  And this was prominently advertised on the sides of these packets – “contains baking soda and peroxide.”

These came on the market perhaps a decade ago or so, and seemed a terrific idea.  Peroxide is an excellent bleaching agent which decomposes to oxygen and water, so it leaves no residues behind.

But now, they have all disappeared.  And that’s all brands.  There used to be half a dozen different options as a choice for whitening toothpaste, all of which contained baking soda and peroxide.

So what happened?

Well, in the world of consumer marketing, the appearance of performance is more important than performance itself.  And no doubt some bright spark in marketing for one of the companies decided that since they now had the market, they could cheapen the products by cutting out the baking soda and peroxide but still leaving all the bright and pretty colours on the outer packaging.

They figure that most people don’t comb through the ingredients and therefore the peroxide would not be missed by anyone.

This happens a lot – once a company gets a market, they reduce the quality to make it easier for them to make money, as the formulation is now cheaper.  They just hope that no one notices.

I didn’t.  I was surprised by the CHOICE article as toothpastes with these products most certainly did exist in the recent past. Did one brand change formula and the others follow? Don’t know.

So there you go – get an el cheapo toothpaste – don’t waste your money on the more pricey brands with the pretty packaging..