Chemistry behind teeth whitening
Any process that lightens the colour of a tooth is known as teeth whitening. Whitening of the tooth or teeth can be accomplished by removing stains physically. Even any chemical reaction that results in stain removal is also considered as teeth whitening. Chemical degradation of chromogen is considered as bleaching. Hydrogen peroxide is the most commonly used active ingredient that remains present in the majority of whitening products. Hydrogen peroxide also remains present as carbamide peroxide in many products as the active ingredient. Carbamide peroxide is more stable in form. When it comes in contact with water it breaks down on its own to release hydrogen peroxide.
In the chemistry of almost every teeth whitening, it is hydrogen peroxide that remains as the backbone. This is because carbamide peroxide ultimately releases hydrogen peroxide. Stains on the tooth are caused by a compound called chromogen. Chromogen has a darker colour or shade than the tooth enamel. The chemical gets accumulated on the tooth either on its intrinsic surface or intrinsic. This is how stains are categorised as either intrinsic or extrinsic stains. Chromogen is again categorised into two parts – metal containing compound and large organic compound with conjugated double bond.
When the organic compound is bleached using hydrogen peroxide it involves reacting with the double bond. This results in oxidising the double bond. As a result of oxidisation the chromogen turns lighter in colour. On the other hand bleaching of metallic compound is not so easy. That is why procedures like dental crowns, veneers or bonding are considered better aesthetic options compared to bleaching the metallic compound. In some commercially manufactured whitening products sodium hypochlorite is present. It reacts with the double bond of chromogen is somewhat the same manner as hydrogen peroxide.
Different types of whitening products are there in the market to deal with different types of stains on the teeth. A dentist having years of expertise in teeth whitening in Wimbledon says these products can be broadly categorised as the following –
- Cleansers or smokers’ toothpaste – This range of products contains large proportions of abrasives and detergents to get rid of chromogen coating from the surface of the tooth.
- Bleaches – This variety of whitening products reacts with chromogen to lighten its colour.
In the third category there are products that are packed with both cleansing and bleaching agents.
Usually severe and complex stains are best dealt with professionally. The products that are available over the counters are meant for milder cases of staining of the tooth. The time required for these different products to show results also varies widely. Time depends on the time of exposure and the concentration of a bleaching compound in a given product. Usually when you are using cleansers or any over the counter product there is usually 1 to 2 shades of whitening is expected and not more. But while you are professionally whitening your teeth it can easily whiten up to several shades.
Different types of teeth whitening systems
Whitening systems meant for the teeth can be broadly categorised.
Whitening toothpastes – Whitening toothpastes are popular products in the market. Varieties of these products are readily available over the counters. This range of whitening products contains a higher proportion of abrasives and detergents compared to standard toothpastes. As a result whitening toothpastes can take care of tougher stains on your teeth surface. Whitening toothpastes do not contain bleach or active ingredient like sodium hypochlorite. Rather few of these products contain low concentration of either carbamide peroxide or hydrogen peroxide. Both the ingredients are effective getting rid of stains from the teeth surface. Whitening toothpastes can lighten the colour of the teeth by about one or two shades, says a dentist who deals in teeth whitening in Kingston over the years.
“Over the counter” or OTC whitening gels and strips
Whitening strips hit the market in the late 1980s and since then their demand has steadily gone up. These strips have a thin layer of peroxide gel. The gel comes on a plastic strip. The strip is perfectly shaped to fit to the teeth surface. There are different types of these strips and each type has a different set of instructions to follow. As standard instructions one has to apply the strips twice daily. Apply it for half an hour a day for a stretch of two weeks. Lightening of the stains can be seen after using a product for several days. Your teeth will lighten up by one or two shades on using these OTC strips. Newer strips are also there in the market. You have to use this latest version of strips once daily for half an hour. However the result is the same irrespective of the kind of OTC strip you use.
Whitening gels on the other hand are mostly peroxide base. Using a small brush you are supposed to apply these gels directly to the teeth surface. Most manufacturers recommend using these gels twice daily for a stretch of 14 days to get results. Just like whitening strips the gels too can lighten the teeth by just one or two shades and not more explains a dentist who provides teeth whitening in Richmond.
Tooth whiteners based on trays
Tray-based tooth whiteners are available over the counter and as well as professionally. The method is quite simple; there is a fitted tray that contains carbamide peroxide as the bleaching gel. You are supposed wearing the tray overnight or for 2 to 4 hours depending upon the kind of product you choose. Results will be noticeable after a few days. However this range of products too lightens the teeth by only one to two shades.
Tooth whitening and risks involved
Two types of risks are usually associated with this cosmetic dentistry treatment, namely increased sensitivity in the tooth and minor gingival irritation. If the concentration of the peroxide bleach is high the level of sensitivity or irritation is likely to be higher and vice versa. Even duration of the treatment also matters. If you use a composition that has no bleaching component then side effects may not occur as well. A dentist associated with Sw19 Confidential Dental Clinic says sensitivity in the tooth usually lasts several days and it occurs at the time of the Philips Zoom Teeth Whitening Wimbledon treatment. Even gingival irritation also lasts several days although it usually occurs within a day of undergoing the treatment.