What are your teeth made of?
Before we get into the details of tooth-whitening, let’s take a minute to meet the enemy. What are tooth stains anyway?
Each tooth is made up of an inner dentin layer and a hard outer enamel layer, which protects the teeth. When you eat and drink or smoke, a microscopic build up of particles over time accumulates to form a pellicle film over the enamel layer.
Regular visits to the dentist can help destroy this unwanted pellicle layer through scraping and chemical treatments. You can even help yourself by brushing regularly but simply brushing your teeth won’t remove all of it. Brushing with toothpaste cleans the tooth in the same sort of way scrubbing with an abrasive pad cleans a dish. “Whitening toothpastes” are designed to work even harder on this layer by being more abrasive.
The problem is, as this pellicle layer sits on your teeth for years and years, the build up gets into the enamel. The enamel layer is made up of hydroxyapatite crystals, which form microscopic hexagonal “rods”. Simply put, enamel is porous, which means staining agents can work their way down into the tooth, where you can’t simply scour them away. The deeper stains are essentially harmless, but many people find them unattractive.
This is where the true tooth whiteners that I use excel. The whiteners use bleaching chemicals to get down into the tooth enamel and set off a chemical reaction (specifically, an oxidation reaction) that breaks apart the staining compounds.
Most tooth whiteners use one of two chemical agents: carbamide peroxide or hydrogen peroxide (the same stuff that will bleach your hair). When used in the mouth, carbamide peroxide breaks down into hydrogen peroxide and urea, with hydrogen peroxide being the active whitening ingredient.
There are a number of different ways of setting off this basic process. Let’s look at the main options.
I’ll be back with the main options later…stay tuned..
