Tooth whitening explained

In this age of social media and selfies it seems that there has been a huge increase in the amount of people who want whiter teeth. There are so many whitening options on offer that it’s not surprising to find many people are confused about what option would work best for their teeth and budget. Some of the options available now include: whitening toothpaste and mouthwash, whitening pens and strips, take home whitening kits from a dental professional (includes whitening gel and custom made whitening trays), and the in-office whitening procedure performed at a dental clinic. Which option to choose often comes down to the answers to three questions. How white will my teeth go? How long will it take for them to get that white? How much will it cost? This blog will attempt to answer some of these questions.

Why do teeth stain?

Teeth stain because tooth enamel is porous and absorbs the colours from the food and drink we consume. Sometimes the staining can be just on the surface of the teeth. A really thorough scale and clean with the hygienist can instantly make teeth that have only this surface staining look whiter, and even if this is not be the case, it is always recommended that prior to doing any tooth whitening, a thorough clean should be performed. Over time, staining can penetrate deeper into the tooth enamel and when this happens, cleaning alone will not be able to remove this type of deep staining. This is when tooth whitening can help.

How does whitening work?

Most whitening products contain hydrogen peroxide or carbamide peroxide. These chemicals penetrate into tooth enamel and chemically break down the staining. Whitening products vary in terms of the concentration and this is why some whitening products and procedures work better and/or faster than others.


Not everyone is suitable for teeth whitening. A consultation with a dental professional is recommended to determine which option would be the most appropriate as well as discussing the risks and benefits along with an indication of likely results. Whitening is not recommended for people with crowns, veneers, periodontal disease, those requiring dental restorations, children, pregnant or breastfeeding women. As some tooth whitening may exacerbate tooth sensitivity your dental professional may recommended a prophylactic course of a recalcifying agent prior to the whitening procedure.


In-office whitening

This option is by far the quickest and most effective way to whiten teeth, it takes just one, 1hour appointment to achieve noticeably whiter teeth. For those wanting that super white Hollywood smile, this is in all likelihood, the easiest and most cost effective way to achieve that look. In saying that though, results from any type of tooth whitening procedure will differ from person to person. Philips Zoom In-office whitening is an example of the in-office tooth whitening. In the appointment a highly concentrated whitening gel (available only to dental professionals) is applied to the teeth and a light is used to help speed up the penetration of the hydrogen peroxide or carbamide peroxide through the enamel. This treatment usually takes around an hour to complete and consists of three or four 15 minute sessions of whitening. The cost of the procedure is generally around $800.

Take-home whitening kits

Take-home whitening kits are purchased from a dental professional. Impressions of the teeth are taken and used to manufacture clear trays that are custom made to fit over teeth like a thin mouthguard or orthodontic retainer. The dental professional will supply you with a whitening agent to take home. The whitening gel is placed, by you at home, into the trays and then the trays are inserted into the mouth for a set period of time (depending on the product used). The trays are then removed, teeth are brushed to remove the gel, and over the course of a week or two the procedure is repeated until the desired shade is reached. The whitening agent is not as concentrated as that used for the in-office procedure and this is what influences the rate of tooth whitening. These kits cost around half the price of the in-office procedure. However, once the whitening trays have been made, they will last for a number of years and most dental professionals will sell the whitening agent on its own, so in terms of maintaining your white smile, this is a great option. Some people who have the in-office whitening procedure will also purchase a take-home kit which they then use to maintain their new shade.

Whitening pens and strips

These products are readily available at the supermarket or on-line. They all contain some form of peroxide (as the whitening agent) however due to the concentration of the peroxide it is likely that teeth that are moderately or heavily stained will not be lightened more than one or two shades with these types of products.

Whitening toothpaste and mouthwash

Purchased from the supermarket, these products have a reduced amount of active whitening ingredient as they are routinely used twice daily. Often the combination of a whitening toothpaste and whitening mouthwash can be quite abrasive to tooth enamel and the use of one or the other and not both is recommended. As with whitening pens and strips, the results with these products will vary depending on how dark or yellow the tooth enamel is to begin with. Tooth enamel may lighten between one or two shades. The cost of whitening toothpaste and mouthwash varies between supermarkets and products however expect to pay around $10 for a good whitening toothpaste.

How long does it last?

Tooth whitening won’t last forever and how long it does last for varies considerably. Often it depends on each individual’s oral hygiene practices and the types of food and drink consumed. Typically the in-office whitening will have the longest lasting results as the hydrogen peroxide penetrates deeper into the enamel, however many people are happy with the results achieved with the take-home whitening kit as they are able to give themselves a top up whenever they like, particularly before a big event.