Thinking about trying that home remedy whitening recipe you found on Pinterest, starting whitening strips or buying a new whitening kit? You may want to think twice before you go for it. While these products seem to really work, most of us are not actually paying attention to what we are putting in our mouths.
All whitening products contain hazardous and very acidic and toxic ingredients. Most whitening products are peroxide based and contain hydrogen peroxide and chloride dioxide as their main bleaching agents. When these bleaching agents come into contact with teeth, they diffuse through the enamel and dentine layers of the tooth, releasing free radicals. Free radicals break double bonds that hold pigments together in the pulp chamber of a tooth. This causes an alteration of pigment and whitens the tooth. While this mechanism is very effective, it destroys the enamel layer and causes heightened sensitivity to hot and cold items. This only lasts temporarily and the pigment will eventually undergo a rebound period and return to its original shade. This requires routine use of the product to maintain white teeth, and will continuously destroy the enamel layer.
Another mechanism of whitening products is called enamel dehydration. When bleaching agents come into contact with the enamel layer, the enamel is dehydrated creating a whiter appearance under the enamel. This mechanism also only lasts temporarily until the enamel is rehydrated, restoring the tooth to its original shade.
Beyond the actual disintegration of the enamel layer, other side effects occur with the use of whitening products. These symptoms include loss of minerals, ridges in the tooth, changes in the shape of the tooth, loss of microhardness, loss of shine, and a higher frequency of surface stains. The chemicals used may also cause gingival infections, resulting in burning, blistering, and tissue ulcerations. On a cellular level, many cancerous abnormalities are found.
When the peroxide agents enter the oral cavit,y they release free radicals, which are extremely reactive and damage the cells through ATP depletion and apoptosis. Free radicals accumulate due to the body’s inability to metabolize them. Free radicals are known to cause cancerous effects in the oral cavity and may also promote tumors. Free radicals cause breaks in DNA strands as well as genotoxic and cytotoxic effects on cells. A number of assays have been conducted to test the genotoxic and cytotoxic effects.
Assays used to test the toxicity of whitening products reveal higher frequencies of micronuclei, chromosomal aberrations, apoptosis, and decreased communication between cells, which is an early stage of tumor formation. There is also a link between high concentrations of hydrogen peroxide ingestion and risk of mutation in ATM and BRCA1 genes which increase risk of breast and ovarian cancer.
While these studies seem to show alarming results for more intense whitening products, it is also important to consider whitening toothpastes. Whitening toothpastes definitely show higher toxic effects, although it seems that whitening toothpastes are not so bad due to natural enzymes secreted in the salivary gland. Salivary peroxidase is an enzyme which, when secreted, helps break down peroxide ingredients. Salivary peroxidase can metabolize up to 80% of hydrogen peroxide from whitening toothpaste after one minute of brushing teeth. While this can be a way to avoid the toxicity of whitening products, most other whitening products are used for longer periods of time as well as in greater concentrations, which decreases salivary peroxidase’s catabolic efficiency.
Although peroxide agents in whitening products are mostly found in lower concentrations, they do not cause severe immediate effects to cause major concern. While most products have some sort of genotixic risk, it is important to be cautious of the concentrations of peroxide agents in our whitening products, making sure that it does not exceed 15%. It is also extremely important to rinse the mouth after use of whitening products of any sort to prevent digestion. Almost 10% of the hydrogen peroxide is digested after using at home whitening products which is damaging to the digestive tract.
So what is the safest whitening method? Studies conclude that getting whitening treatments from a dentist is the safest route. Dentists use protective measures to limit the damage of the toxic chemicals found in these treatments by limiting the contact between the whitening gel and the gums to avoid ulcerations and rinsing the mouth out after treatment to rid of any residual chemicals. Obviously professional dental treatments are the safest way to go, but if you are using at home whitening kits, be aware of peroxide concentrations and do not forget to rinse!