The popularity of whitening (bleaching) is understandable as it provides the patient with a fast result, which is non invasive and affordable. However, proper thought and caution must be exercised to appreciate the process and its limits in meeting a patient’s expectations.

TOOTH DISCOLOURATION

Tooth discolouration is caused by large pigmented organic molecules located on the surface of the tooth or embedded within the tooth’s enamel and/ or dentin structure (i.e. internal or external). External surface stain can be removed by mechanical cleaning and is generally caused by tobacco, tea, coffee, red wine, berries and plaque accumulation. Penetrating external stain is due to microscopic cracks and porosities in the enamel, thus the resulting stain cannot be removed mechanically and must be treated chemically.

Internal stain refers to stain: which is incorporated into the tooth during its development; from genetic/systemic conditions; associated with trauma, dental conditions (decay, old restorations) and ageing.

DIAGNOSIS

Successful treatment depends on proper diagnosis and treatment planning which includes a review of medical/dental history, oral hygiene and clinical conditions. If whitening has been determined to be a viable choice of treatment, success is dependent on patient compliance, condition of teeth, type of stain and the concentration, amount and delivery system of the bleaching material.

MECHANISM OF WHITENING

Tooth whitening or bleaching is achieved by the oxidation of organic particles due to release free radicals from activated hydrogen peroxide penetrating the tooth structure. The activation is accelerated by heat which can come from body heat,  or application of a high intensity light. Studies have suggested there is no difference in the efficacy of bleaching materials when used with or without light activation. The free radicals interact with the large organic pigment molecules with in the tooth and are broken down into smaller less pigmented molecules, thus reducing the pigmentation of the tooth.

TYPES OF WHITENING SYSTEMS/EFFICACY

The market is flooded with products and claims making the proper choice difficult for the consumer. The process is easiest to understand by categorizing the different delivery systems and their efficacy to allow patients to decide what is best for their needs and expectations. In order of least to most effective the categories are:

Over the Counter Products ( consumer – minimum strength )

Whitening Toothpastes -> Paint-On -> Whitening strips/ “Stock” Home bleaching trays

Advantages – convenience, relatively inexpensive. Disadvantages – weak concentration of active ingredient, takes long time to get desired results, frequent re-treatment required, increased long term costs.

Dentist Supervised ( professional  - maximum strength )

Whitening strips/ “Stock” Home bleaching trays  -> “Custom” home bleaching trays -> In Office bleaching trays/ Power bleaching

Advantages – excellent results, high concentration of active ingredient, short treatment time frame, relatively inexpensive (dependant on delivery mode). Disadvantages – chance of transient thermal tooth and/ or gum sensitivity, cost (if absolute immediate results desired)

MAINTENANCE

Shade relapse varies with each individual. Generally, you should expect some relapse within the first six to twelve months.  In most cases, a simple short term re-treatment using a touch up kit (1-3 days) will restore the original “post bleaching” result; however, many patients notice very little, if any relapse after twelve months.

SAFETY

The Canadian Dental Association (CDA) and American Dental Association (ADA) have position statements concluding that the bleaching process is a safe and effective method of whitening teeth without any long term deleterious effects.

Important Notice

To summarize, as the effectiveness of the whitening product increases, so does cost and chance of potential side effects.

All patients expect excellent results and nearly all believe they are a good candidate for a whitening procedure. The level of whitening cannot be guaranteed despite what some advertisements claim, and the treatment will not whiten existing restorations. These are general guidelines, meant for informational purposes only and not meant to encompass and explain all aspects of whitening/bleaching but encourage you to think before you act.

Always consult your dentist to discuss your specific needs prior to any treatment.

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