Tooth Whitening / Bleeching
Guidelines and Recommendations on Tooth Whitening/Bleaching procedures in Singapore
(Revised as of 21 Jan 2013 in consultation with HSA)

In view of patient safety when it comes to tooth whitening/ bleaching procedures, it is strongly advisable for the public to understand the importance to have a proper oral examination by a dental professional and determine the most appropriate whitening treatment to be advised or prescribed under supervision.

SDA recommends the following guidelines for the sale and prescription of tooth whitening / bleaching products:

1. Tooth whitening products that contain concentrations up to 0.1% hydrogen peroxide (equivalent to 0.3% carbamide peroxide), is allowed in oral hygiene products for application by consumer. This would include products such as tooth-whitening toothpaste.

2. Tooth whitening products that contain concentrations up to 6% hydrogen peroxide (equivalent to 18% carbamide peroxide), can only be prescribed by a registered dental practitioner for home use by the patient, and only after consultation with their registered dental practitioners. Such products is not for direct sale to the general public.

3. Any tooth whitening products containing concentrations above 6% hydrogen peroxide and up to 35% hydrogen peroxide can only be legally accessed by a registered dental practitioner. Such products should only be used on patients in the dental clinic under the supervision of the registered dental practitioner.

Background Information

Tooth Whitening / Bleaching procedures are becoming very popular for patients seeking esthetic dental treatment. The sources of tooth whitening treatment can be broadly classified into 4 categories:

1. Professionally applied (In-Office) by a dentist 

2. Dentist-Prescribed/Dispensed for patient home use 

3. Consumer-Purchased /over the counter (OTC) 

4. Non-Dental Options Traditionally, patients will consult a dentist for tooth whitening treatments or purchase from the pharmacy consumer tooth whitening products that are safe for home use.

The latter option is unsupervised and not in consultation with a dentist. Recently, there is an increasing number of non-dental outlets specifically for providing instant tooth whitening services to the public. These services are provided by “therapists” who do not have any prior training in dentistry. In untrained hands, the relatively safe bleaching procedure can have potential and significant damage to the teeth. There are concerns about the long term

safety of unsupervised bleaching procedures, due to abuse and possible undiagnosed or undetected underlying oral problems.

Although tooth whitening is a relatively safe procedure, there are still increasing reports of adverse effects on hard tissue, soft tissue and restorative materials.

Safety Considerations on Bleaching Material:

Bleaching material consists of a variety of peroxide compounds, including carbamide peroxide, hydrogen peroxide, sodium perborate and calcium peroxide. Currently, carbamide peroxide and/or hydrogen peroxide are used as extra coronal bleaching materials. Most OTC bleaching products are hydrogen peroxide based chemicals. Typically 10% carbamide peroxide will decompose to release 3.5% hydrogen peroxide in an aqueous medium. In-office bleaching materials contain higher percentage of hydrogen peroxide (15-38%) than at-home bleaching products. (3-10%); however, there are exceptions when home-use bleaching products containing up to 15% hydrogen peroxide.

Bleaching material with 10% or higher hydrogen peroxide concentration is potentially corrosive, resulting burning sensation and tissue damage on mucous membranes or skin. Those damages can be greatly reduce during office bleaching treatment. Up to two-third of users experience hard tissues, transient mild to moderate tooth sensitivity during the early stages of bleaching treatment. This is because the sensitivity is closely related to the peroxide concentration of the material and the contact time. However, under the help of proper techniques, there is no record on long-term adverse pulpal sequelae.

In summary, extra coronal bleaching treatment done in the dental office or at home may results short-term tooth sensitivity and/or gingival irritation. Higher the hydrogen peroxide concentration, more severe the mucosal damage is possible. As such the use of home bleaching materials and unsupervised whitening procedures by non-dental professionals at higher hydrogen peroxide concentrations should be prohibited.

Treatment Considerations and Patient Safety:

As tooth whitening / bleaching is a form of dental treatment, it should be stressed that prior consultation and examination with the dentist is vital. It is crucial for a thorough oral examination to determine the cause of tooth discoloration and discuss the various options of treatment with the patient. It is also the responsibility of the dentist to detect any pre-existing periodontal disease, caries activity, presence of defective or discolored restorations as well as presence of hypersensitivity in the patient before recommending the best whitening treatment to the patient.

It is also recommended that the dentist ensure caries control and carry out a round of prophylaxis to remove plaque and stains before commencement of the whitening treatment. Hypersensitive teeth should also be treated and defective restorations changed or repaired.

It is in the interest of patient safety that SDA recommends that tooth whitening products containing concentrations up to 6% hydrogen peroxide be prescribed by a registered dentist for home use by the patient, and only after consultation with their dentist.

For higher concentrations above 6% hydrogen peroxide and up to a maximum of 35% hydrogen peroxide, it should only be legally accessed by a registered dentist. Such products should only be used on patients in the dental clinic under the supervision of the registered dentist.

Dr Chye Chuan Hee Kelvin
Vice President, Council 2014-2016
Singapore Dental Association
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