If you are one of millions of people dreaming of a dazzling Hollywood smile, and your teeth have lost their lustre, science is at hand to help.
A new video from the American Chemical Society delves into the science of why our teeth lose their whiteness, and how the products used to make them gleam again do their job.
A new video from the American Chemical Society has shined the dentist’s spotlight on why our teeth lose their whiteness, and explains the science behind the products used to make them gleam again.
It describes how the tough enamel layer covering our teeth is largely made up of a mineral called hydroxyapatite, which is composed of calcium and phosphate ions arranged into crystals.
The tough enamel covering our teeth is largely made up of a mineral called hydroxyapatite – calcium and phosphate ions arranged into rod-shaped crystals. But molecules of food and drink can become lodged between these crystals, discolouring the teeth.
But molecules of food and drink can work their way in between these rods.
The standard dental weapons of brushing, flossing and rinsing will remove most of this, but some of the stains will stick around. At this stage, most people turn to whitening strips.
According to the video, the majority of these strips use either hydrogen peroxide or carbamide peroxide gel to bleach the teeth. Both of these gels work on the same principle, which is by oxidising the molecules staining teeth. Once a person places the polyethylene strip on the teeth, the peroxide gels react with the stains to remove electrons. This breaks up the part of the molecule associated with colour – its chromophore, which gives the colour depending on the wavelengths of light it absorbs.
Whitening gels use peroxide, an oxidising agent that ‘steels’ electrons from the molecules staining the teeth. This disrupts the chromophore – which gives the molecule its colour – in the same way bleach cleans stains from clothes.
Disrupting the chromophore is the same mechanism used by bleaching products that remove stains from clothes.
But while people may opt for a mouthwash, the active ingredient will be peroxide.
And the video explains that due to the longer contact time with the teeth, the gels will win out in terms of whitening performance.
The easiest solution may be to reach for whitening toothpaste, and kill two birds with one stone by whitening teeth as you brush them, but this method fails to scratch the surface. Although whitening toothpastes may contain abrasive elements such as silica, the video explains that they may only clean the surface and don’t reach down to the enamel. Some of the whitening toothpastes contain a substance called blue covarine.
‘This binds to the surface of your teeth adding a bit of blue to balance the yellowish gunk on [your teeth],’ the video explained. The effect is designed to filter the teeth’s hue.
Assuaging safety fears of using whitening products at home, it confirms that the over-the-counter products are certified as safe – personal sensitivity notwithstanding – and are essentially the same as what a dentist would use.
Overall, the best method to clean teeth is peroxide, but results will vary depending on the type and degree of staining a person has.
But undoubtedly, the fastest results will come from a trip to the dentist.
