Does 40% H2O2 whiten faster than 15% H2O2? Does it mean that more hydrogen peroxide means whiter teeth?
One of the most common methods to keep the Hydrogen Peroxide ratio in Teeth Whitening gels as constant as possible is to lower the level of water, i.e. to add additional stabilizers to the high rate of hydrogen peroxide.
Gels with more chemical stabilizers in contrary could be less effective when used for whitening. Stabilizers are used to prevent the spontaneous reaction of hydrogen peroxide and slow down its degradation. When such products start to whiten, hydrogen peroxide reacts slowly and causes less whitening agent to be released (free-radicals).
Since such whitening gels also have an acidic pH value (for a long shelf life), not only the drop of peroxide level does not significantly slow down but also produce more water and molecular oxygen instead of releasing ions and free radicals that are effective in whitening.
Although molecular oxygen is able to whiten with oxidation effect, it is not capable of separating large chromic molecules (chromophore) from ions and free radicals, which are the main factors in whitening. For effective whitening, these stains have to be shredded, and this can only be achieved by the release of free radicals.
When the oxidation effect due to a high rate of hydrogen peroxide applied several times over a total of 30 to 45 minutes is combined with the effect of excessive dehydration, a rather surficial and chalk colored whitening could be achieved. Most of the time, since enough amount of free radicals are not exposed, chromophore molecules that give the original dark color to the teeth are not sufficiently fragmented. And a few tones of reversal to grey is a common occurrence when the tooth is reintroduced back with its water in a few days. This is a common condition and most of the time there will be a need to perform an additional session of tooth whitening within a few weeks.
When not stored in cold environment and in good conditions, Hydrogen peroxide content of products containing high hydrogen peroxide decreases rapidly. They can reach a more acidic structure that goes down to pH 3.5 levels. This is often seen as more frequent tooth sensitivity.
While High hydrogen peroxide ratio and the addition of more stabilizers help to solve a problem, such whitening gels which cannot release enough whitening agents, can become a more problematic product for dentists.
So does low-level hydrogen peroxide whiten in 1 hour? Have a look at the BioWhiten ProOffice cases below to see the effect