Vital bleaching, a.k.a vital tooth whitening, is a method of lightening the colour of the surface enamel without removing any tooth structure.
Some common reasons for tooth discolouration are: darkening of the teeth with age (thinner enamel, and/or thicker dentin), outside (extrinsic) stains from coffee, tea, smoking, or pigmented food, or light inside (intrinsic) stains from fluorosis (ingestion of too much fluoride while a child) or antibiotic therapy.
As the teeth are still vital (alive), the whitening agent is applied to the enamel surface. The products used for vital whitening of teeth, enable oxygen to enter the microscopic interprismatic spaces to lift away discolouration.
If you are going to be receiving treatment, you must be made aware that the results are not permanent, extrinsic stain can return within 3-5 years depending on the cause.
The success of whitening procedures is dependent upon the following factors: cause or type of discolouration, degree or intensity of the discolouration or stain, bleaching agent selected, length of exposure of the tooth to the whitening agent, technique used for whitening the teeth, presence of cracks in the surface of the tooth, presence of any restoration in the tooth (composite, bridge, crowns, dentures cannot be whitened)
Before a patient has this procedure done, you must be screened first. This includes insuring that they do not already have sensitivity to any of the bleaching agents, and the patients teeth must be cleaned completely because stains can stick to the plaque and calculus on the teeth. Also the patient must have reasonable expectations, and realise that your teeth may not look like a celebrity's teeth, because everyone has a different bite, and arch size.
Chemical Agents Used In Tooth Whitening
Two of the most common agents used in tooth whitening products are hydrogen peroxide and carbamide peroxide. When these products are applied to the teeth the peroxide will break down into oxygen molecules which can work their way through the dentinal tubules and into the tooth where they attach themselves to stain particles and effectively break the stains apart. The reason that stains make the teeth look dull is because light is not able to shine effectively through the teeth. When the peroxide agents break the stains apart there is less blockage of light which makes the teeth appear brighter and whiter.
- Hydrogen Peroxide
- strong oxidizing agent
- readily decomposes into water and oxygen
- can penetrate enamel and dentin and may produce reversible pulpitis (sever sensitivity)
- precautions must be used to protect the patients eyes, face, intraoral soft tissues and clothes from the solution.
- solution is applied to the teeth in either liquid or gel form and in strengths varying from 5%-35%
- Carbamide Peroxide
- weaker oxidizing agent, but is more stable then hydrogen peroxide
- applied in either liquid or gel form
- strengths varying from 10%-15%
- also contain a thickening agent that increases adhesion of the gel to the tooth, which prolongs exposure
- not as much damage to the tooth
- contain silica, aluminium oxide, calcium carbonate, or calcium phosphate particles
- these may only debride the surface of the tooth to remove extrinsic stains
- will also cause some sensitivity
- whitening strips contain a whitening gel and are applied to the surface of the teeth to be whitened
- the strip must reamain on the teeh for the recommended time to be effective
- the procedure is often repeated for a few days or weeks at a time
