Many people often visit pharmacies to ask for solutions to stained teeth. We write to highlight to pharmacists briefly the different types of staining and treatment options available.
Staining of teeth may be external (extrinsic) or internal (intrinsic). Intrinsic staining may be caused by malformation or hereditary conditions of enamel and dentine, systemic illnesses (e.g. hepatic or haematological), medication, notably antibiotics, especially tetracyclines, during tooth development, excessive consumption of fluoride in early childhood (fluorosis), or related to dental caries, trauma resulting in bleeding of the dental pulp into dentine, dental fillings and aging and wear of the teeth.
Extrinsic staining, exacerbated by the presence of calculus (tartar) and other deposits on the teeth, damaged and ill-fitting fillings and rough, worn or damaged areas on teeth, is caused by the build-up (i.e. failure to remove) of colourific materials from food. Coffee, red wine and curries are often implicated as are habits such as tobacco use, or from the oral use or consumption of certain agents and medicines. Many teeth with intrinsic staining may also display extrinsic staining, patients with intrinsically stained teeth tending to be poorly motivated to remove and control extrinsic staining.
Intrinsic staining of teeth is best managed by the dental team using professional tooth bleaching agents. The tooth bleaching agents normally contain hydrogen or carbamide peroxide. The most commonly used product is 10% carbamide peroxide tooth whitening gel. The gel is placed into specially designed trays which fit closely over the teeth. The trays are normally worn when the patient sleeps. Such home-based bleaching, or tooth whitening, which removes stain deep into the dentine of the tooth, may be kick-started or carried out as an in-surgery treatment. Even under carefully controlled conditions, tooth sensitivity is a relatively common adverse effect of tooth whitening.
Kits for ‘DIY’ management of intrinsic staining of teeth, which are available on the internet, may either be found to be ineffective or, if they include a bleaching agent of sufficient strength to effect the internal bleaching of teeth, may pose certain risks to the consumer and their teeth, especially if excessive bleaching agent is used, often coming into contact with the oral mucosa, which may suffer painful, slow-to-heal chemical burns.
Most off-the-shelf dental whitening products, which typically take the form of toothpastes, mouthwashes or chewing gums, have little, if any, effect on intrinsic staining deep in the tooth. Certain self-applied strips and other off-the-shelf dental whitening products may lighten teeth, but the extent of the whitening is typically limited relative to what may be achieved by professional bleaching. Such appearance changing, monitored bleaching or tooth whitening is the practice of dentistry and, as such, is illegal if attempted by a non-dentally qualified person in, for example, a beauty salon or spa.
Extrinsic staining of teeth and any aggravating factors, such as the presence of calculus, are best managed by professionally ‘scaling and polishing’ of the teeth, the principal work of dental hygienists, followed by any remedial dental work to deal with any stain-susceptible fillings or areas of dental ‘wear and tear’. Off-the-shelf tooth-whitening products, which can be of help in dealing with limited surface discolorations and in preventing the early recurrence of extrinsic staining, especially if used as part of a professionally recommended oral hygiene regimen, may be found, when used alone, to have widely varying effectiveness in dealing with marked established extrinsic staining, depending on the nature of the staining, some of which can be resistant to removal, and the frequency and form of usage of the product.
In all tooth-whitening procedures, it is to be remembered that, although the colour of teeth may be changed, the colour of any dental restorations — fillings, crowns, veneers, or dentures which are present will remain unchanged, typically making them more apparent, and thereby diminishing the aesthetic qualities of the smile. Therefore, individuals with replacement or filled teeth they want whitened should be advised to seek dental assistance
Off-the-shelf tooth-whitening products, when used alone, may reduce extrinsic superficial staining on teeth and provide limited ‘whitening’ of intrinsic staining in sound teeth. Such products may help the early recurrence of extrinsic staining in, for example, heavy coffee drinkers or smokers, when used as part of a professionally prescribed oral hygiene regimen. Individuals seeking to reduce unsightly intrinsic staining or ‘whitening’ of relatively dark teeth, especially those with existing fillings, crowns, veneers or dentures, should be advised to seek professional help.
Tooth whitening is not without certain risks, but these may be minimised by seeking professional advice. DIY whitening can go badly wrong and off-the-shelf products when used alone to manage established, difficult to remove staining may fail to meet expectations and disappoint.
Nairn H F Wilson
Emeritus Professor of Dentistry, King’s College London
Private practitioner, London