Article by Dr Angela Ngauw, General Dental Surgeon, BDS (S’pore)
A set of sparkling white teeth can make one look younger, more attractive, more professional and successful – it is no wonder then that many people want to whiten their teeth. But, with a range of whitening products available in the market, many are unsure of how the various products work and which is the most effective for them.
Whitening options range from over-the-counter whitening toothpaste and whitening kits to dentist-supervised home bleaching and in-office bleaching. To find out which product is most suitable for you, it is best to do a check with your dentist first, as different people have different dental conditions as well as different types of stains, which may require specific treatments. In other words, what worked wonders for someone else may not work at all for you! Your dentist would be able to help you tailor your treatment to achieve your desired outcomes in the most effective way.
Here are some of the whitening products available:
a. Whitening toothpastes
Whitening toothpastes contain micro-abrasives, which abrade and smoothen the surface of the teeth when brushed on. In that way, whitening toothpaste may be able to remove some of the superficial surface stains and polish away the rough plaque-trapping surfaces of the teeth. However, this toothpaste will not be able to remove stains in the deeper layers of the teeth or in areas which are not easily accessible by the toothbrush. Hence, their whitening effect is usually minimal at best. Prolonged usage of whitening toothpaste may even lead to excessive wear of the enamel and result in sensitivity.
b. Whitening kits / Whitening by beauty therapists
Over-the-counter whitening kits and products used by non-dental beauty therapists usually contain peroxide-based chemicals which act to bleach the teeth. However, the concentrations of active ingredients in these products are restricted by the Ministry of Health1 to be of such a low concentration that the whitening effect is again minimal at best. These products may also cause sensitivity and gum irritation, if used incorrectly.
Your dentist would first do a thorough dental check-up to ensure that your teeth are suitable for whitening. Your dentist would also need to perform a scaling and polishing to remove plaque, tartar and surface stains on the teeth. This would also ensure that there is maximum contact of the whitening gels with the tooth surface. There are 2 types of dentist-prescribed whitening: home whitening and in-office whitening. Both whitening systems work by having the active ingredients enter the inner layers of the teeth and break down the pigments and deep discolorations within the teeth.
a. Home whitening
In home whitening, moulds of your teeth are taken to fabricate customised trays that fit your mouth. You would be given the trays and whitening gels, and taught how to use them at home. The gels are applied onto the trays, which are fitted over the teeth. There are varying concentrations of these gels and depending on the concentration, the duration of usage also varies, ranging from 30 minutes to 8 hours daily, over a period of about 2 weeks. The teeth would gradually lighten in shade over this period.
b. In-office whitening
In contrast to home whitening, in-office whitening treatment is done at the clinic and it usually takes about 2 hours. In this treatment, the dentist would first protect the gums and lips with a suitable barrier, and then apply the whitening gels onto the teeth. As the duration of the treatment is much shorter compared to home whitening, the concentration of the gels are also much higher. Therefore, patients who wish to see faster results or find the take-home trays troublesome, may opt for in-office whitening instead.
In all whitening procedures, some patients may experience temporary side effects such as sensitivity and minor gum irritation. Your dentist would be able to help you manage these by applying desensitising varnishes or other medications.