LED or any form of teeth whitening that is not performed by a dentist practicing in a licensed dental clinic is not subjected ANY oversight and regulations by national health and safety authorities. You are essentially at the mercy of the manufacturer and the service provider and any claims that they make about their products and services.
If professionally-administered (in-clinic whitening) or professionally-supervised (take home whitening) teeth whitening is done by a licensed dentist with the proper materials and equipment, there is minimal to NO RISK that this will harm your health or cause injury to the soft tissues (gums, lips, tongue, cheeks) of the mouth.
The peroxide gels used by dentists have enough peroxide to bleach dark compounds within enamel. There are 2 forms of peroxide used, generally hydrogen peroxide (fast-acting but unstable during storage) and carbamide peroxide (slow-acting but more stable).
Hydrogen peroxide gel used during in-office whitening (with a bleaching lamp) is usually supplied at 25% and for this reason, the soft tissues need to be protected from the gel by a special barrier material. Bleaching lamps are used to accelerate the breakdown of the hydrogen peroxide gel and speed up the bleaching process. Most bleaching lamps use high powered LED light.
For take home whitening, between 10-15% carbamide peroxide gel is used or 6% hydrogen peroxide gel, which may still cause mucosal irritation if left in contact with the soft tissues for a long period of time. Your dentist will make customized bleaching trays that fit snugly over the teeth and the gum margins to hold the bleaching gel in place and prevent it leaking out and causing irritation. Take home whitening is done gradually over 3-4 weeks.
If the person performing the whitening treatment is not a trained dentist, there are a few things that may happen:
1) Unsatisfactory results
If the bleaching gel being used does NOT contain any peroxide or only a very small percentage (the concentration that can be sold over the counter to non-dental professionals is restricted to 0.1% hydrogen peroxide) then you may not get any permanent teeth whitening! Very often, the act of holding the lips away from the teeth to shine the LED light on them causes dehydration and a temporary whitening effect which fades after a few hours or a few days when saliva rehydrates the teeth.
2) Inappropriate case selection
Dentists are trained to assess patients considering whitening for problems like tooth decay as well as other causes of tooth discolouration that MAY NOT respond to LED teeth whitening. If whitening gel is placed in contact with an unfilled cavity, it is very painful and in extreme cases, this may cause the nerve of the tooth to die and the tooth may then require root canal treatment.
3) Collateral damage
If the gel being used does contain a high enough concentration of hydrogen peroxide (the maximum allowed in Singapore is 35% and this can only be used in a dental clinic) and NO soft tissue protection has been used, you may end up with chemical burns or irritation of the gums, cheeks, tongue, lips or other areas on the skin of the face or even the eyes that may have come into contact with the gel.
I would encourage you to see a dentist for proper evaluation and management before embarking on any teeth whitening. This should ensure you are properly advised on the likely possible outcome and any special considerations for your case. It is not worthwhile to risk your health for the sake of saving money. You can read more about the regulations on teeth whitening products in Singapore here.
If you are on a budget, take home whitening works well and is well tolerated by most patients.
