Professional whitening: After evaluating and studying the patient’s condition, the doctor begins to take some pictures to allow comparison later after the end of the whitening process. Shades guides are used to determine the degrees of tooth color, such as shown in the picture, to allow the desired degree to be reached.
A gum shield is used to coat the gums to reduce the risk of chemical burns to soft tissues. The bleaching agent may be hydrogen peroxide or carbamide peroxide which converts in the mouth to hydrogen peroxide. The whitening gel usually contains 10% to 44% carbamide peroxide which is approximately 3% to 16% hydrogen peroxide concentration. And the material is left on the teeth, whether the material reacts chemically or activates with light, and the process may take place in two stages according to the need.
During this period, dental molds can be used at home, which are specially made for the person wishing to whiten in the laboratory according to the dental print taken by the dentist, completely matching the shape of the teeth in order to retain the whitening gel, in order to ensure that the teeth are exposed to the gel completely and evenly, and the person fills this mold with low materials the focus.
As for home bleaching, it depends on a low-concentration substance that is less effective than the professional type and is usually done at home. This type includes multiple products, as previously mentioned, for example, the whitening strip, which is thin strips that are placed on the teeth once or twice a day for a period ranging from (5-60 minutes) for a period that may range from 14-23 days of use.[26]
There are different products used at home to whiten the teeth, such as whitening toothpastes and rinses, and although it is accepted that whitening products without a prescription are effective, the result is short-lived.[27]
With the wide availability of whitening products and techniques, the results are usually uneven, as they may appear significantly or may not appear at all.
Recently, light-activated whitening materials containing lower concentrations of hydrogen peroxide appeared with a catalyst composed of titanium oxide particles, because it was found that low concentrations of hydrogen peroxide cause fewer problems in terms of tooth sensitivity and size that prevents it from spreading deep in the tooth. When exposed to light, the catalysts rapidly and locally break down hydrogen peroxide to produce a highly reactive complex of atoms. Due to the extremely short lifetime of the atoms, they are able to produce bleaching effects similar to bleaching with a higher concentration within the outer layers of the teeth.[28]
