Monday, April 07, 2008

Draft Preview: Tooth Whitening Frequently Asked Questions

Hi everyone, I've been slowly working on this for our website, but I decided to put up a preview. It still needs to be fleshed out a bit and the references need to be put in, but I thought this might be useful as is. I will post a more complete version on the blog and website in the near future.

What is tooth whitening?

It is a process of using oxidizing agents, usually carbamide peroxide and hydrogen peroxide to "bleach" areas in the hard outer areas of the tooth (the enamel) that contain stain deposits. Over a period of time, whitening solutions can also lighten the inner areas of the tooth (the dentin).

What causes dark teeth?

In most people, staining of teeth is due to food and drink consumption, especially items that are known to stain teeth (e.g. coffee/tea/red wine). This stain buildup is also often seen with cigarette smoking. In other rare cases, medications such as tetracycline can cause teeth to get darker.

What is the ideal procedure to whiten my teeth?

Ideally, most people require 7 weeks to get a stable colour change with minimal sensitivity. We recommend to our patients to use a desensitizing toothpaste (like Sensodyne-F) for 2-3 weeks before starting to whiten. At the same time, our office takes two impressions, one each of your upper and lower teeth to fabricate custom trays. We then instruct our patients on the proper usage of each kit, usually inserting the trays with whitening gel into your mouth for a period of a few minutes to overnight depending on the type of bleaching desired. After a couple weeks of usage, the desired effects are usually achieved. However, the final stable colour is arrived at 2 weeks after bleaching due to a slight rebound effect.

Will I have sensitivity?

In most cases, yes...ranging from almost none to substantial (this is despite what most manufacturers say). Most sensitivity can be easily managed or eliminated through the use of desensitizing toothpastes and/or gel. This sensitivity is short term and usually stops shortly after the removal of the bleaching trays. Patients who have receding gums and/or many fillings should be aware that they are at a substantially higher risk of sensitivity.

How long does the whitening last?

Usually between 6-12 months before a touch up is required. The actual time depends on a number of factors including coffee/tea intake, staining food consumption, cigarette smoking, and general daily hygiene to name a few.

Will it whitening my fillings or restorations?

No, it does not change the colour of your fillings, thus it is important (if possible) to bleach and let the colour stabilize before restoring teeth so that colours can be matched more accurately.

Does bleaching affect the strength of my fillings and/or teeth?

In general, bleaching does not affect porcelain/gold restorations. It can slightly affect the strength of tooth coloured and silver fillings. It can also slightly weaken cements. To my knowledge, there is no significant evidence showing any structural or irreversible changes to tooth structure.

You seem to promote/prefer the custom tray option versus the in-office 1 hour whitening, why?

I believe it offers the best combination of performance (best results), value (best cost, since it is usually not covered by insurance) and longevity (touch up gels are sold at our cost and only need to be applied every 6 months or so and the custom trays can last up to 5 years).

Hans Skariah, B.Sc., DMD
Promenade Court Dental Health Group in Mississauga
2233 Hurontario St., Mississauga, ON, Canada
(1/2 km north of the QEW in the Dome Building)
(905) 273-7100