Let's face it. Teeth naturally get browner as we get older.
Even if you have impeccable dental hygiene, drinking, smoking or even an innocent daily coffee habit can still cause your teeth to look less than pearly white. What most people don't know is that surface stains (a.k.a. extrinsic stains) are just one part of the problem.
In this blog post we will explore the following topics:
- Tooth structure and sources of discoloration
- Commonplace solutions
- The problem with peroxide
- Peroxide vs. PAP
- The best teeth whitening options
Tooth Structure & Discoloration
Underneath the enamel, we have another layer to our teeth called dentin. This transfers sensation from the enamel to the inner pulp and nerve. Dentin is naturally a yellow color and can darken with age. If the enamel on your teeth erodes and thins, then the yellow from within your teeth can start to show through and give the teeth a darkened and stained appearance. This intrinsic discoloration is much more difficult to deal with.
Since so many people want whiter smiles these days, there are plenty of methods out there that claim to have some lightening effect. There are tons of options out there from whitening gel and strips to regular toothpaste and even blue light gadgets that you hold in your mouth. The vast majority of these products contain bleaches or peroxide.
How Does Chemical Bleaching Work?
The bleach works to alter the internal tooth color through a chemical and physical reaction. Basically, the bleach opens pores in the tooth enamel to allow the agent to seep through to get to the dentin. At the internal dentin layer, the bleach’s oxygen molecules work to lift the discolored molecules from the dentin base, leaving the natural color behind. It is very similar to the mechanics behind how hydrogen peroxide is able to kill bacteria. Some common bleaching agents include Hydrogen Peroxide, Carbamide Peroxide, and Phthalimidoperoxycaproic Acid (we call it PAP, for short).
The Problem With Peroxide
Using peroxide on your teeth as whitening treatment will dehydrate the tooth and increase sensitivity. The sensitivity is caused both by the dehydration of the tooth and also due to the pores of the enamel being exposed. The dentin which is the target of this intrinsic whitening process is the layer of the tooth that transmits sensation to the nerve. Therefore, if there is a direct line to the dentin, sensations are amplified. The longer the product is left on the teeth the worse it gets.
Another problem with peroxide is the longevity of the whitening effect. As peroxide breaks down and exposes the enamel, it makes the enamel more porous. This causes the enamel to act like a sponge and ultimately absorb future stains more quickly. When your goal is to have white teeth, this is a big set back.
Peroxide vs. PAP
Oxidising action is used by both PAP whitening and peroxide-based teeth whitening treatments to break down stains and lighten tooth appearance. During this process, peroxide releases what is known as free radicals. Free radicals reduce discolouration by readily attacking organic molecules, but are also more likely to cause unwanted side effects such as sensitivity, gum irritation, and demineralisation.
PAP similarly reacts with tooth stains, only without the release of free radicals. This means that the molecules responsible for discolouration are broken down safely, without any risk of sensitivity, pain, or damage.
The Best Teeth Whitening Options
When looking for a teeth whitening product, we recommend to read the ingredients carefully and select products that do not contain peroxide. Additionally it is important follow the instructions and avoid overuse. While it may be tempting to use whitening products for longer or more frequently than suggested, this can backfire and make your teeth more susceptible to stains.
Remember: not all whitening products are created equal. And anything that promises instant results is a lie. At the end of the day, white teeth are meaningless without healthy teeth.