Teeth Whitening | The White Arch Dental Centre

Dr Rashmi Hegde | Periodontics and Oral Implantology

Teeth Whitening
The normal color of permanent teeth is grayish-yellow, grayish-white, or yellowish-white. This is usually determined by the thickness of enamel, thickness, and color of underlying dentin and the pulp. Alterations in this color may be physiologic or pathologic, intrinsic or extrinsic. Generally, the color is more yellowish in fair-skinned persons and more whitish in dark-skinned persons. Elderly persons also have more yellowish teeth. Extrinsic discolorations may be due to tea, coffee, fluoride, smoking, bacteria, etc., whereas intrinsic stains may be due to genetic conditions like amelogenesis imperfect, due to tetracycline class of antibiotics, jaundice, pulp necrosis, remnants of restorative materials, etc. Since esthetics is the primary consideration of patients, a discolored tooth or teeth especially in the anterior region definitely causes many patients to ask for treatments to “whiten” or” brighten” the teeth. This is commonly referred to as tooth bleaching. Bleaching is a procedure defined as the lightening of the color of the tooth through the application of a chemical agent (mostly acidic) to oxidize the organic content of the tooth.

The most common bleaching agents used are Hydrogen Peroxide (H2O2) 5%-35%, Sodium Perborate (Used inside the pup chamber, called “walking bleach”), Carbamide Peroxide.

Nowadays Laser tooth whitening using zoom bleaching is gaining a lot of popularity, wherein a Diode laser beam activates the bleaching agent thus speeding up the reaction, enabling faster and better results. Teeth whitening is ideal for people who have healthy, unrestored teeth (no fillings) and gums. Individuals with yellow tones to their teeth respond best. But this cosmetic procedure is not recommended for everyone.



Tooth Whitening / Bleaching Technique

1.Intracoronal bleaching (bleaching of root canal treated teeth from within the tooth/ non-vital bleaching)-

1. 1. 1. At home (walking bleach)- In this, the bleaching agent is placed inside the pulp cavity and sealed. The effect starts after 24 hours. The patient should return 3-7 days after the treatment to assess the change in colour.
      2. In-office or thermocatalytic bleach- In this technique cotton pellets soaked with 30% H2O2 are placed inside the pulp cavity and activated by light and heat. Several 5-6 minute exposures are applied to the tooth.

2.Extracoronal bleaching (from the external surface) or vital tooth bleaching

1. 1. 1. In-office vital bleach- 35% H2O2 is directly applied to the outer surface of the tooth, in the form of gels, followed by activation with heat, visible light, or laser light. Lasers principally work by activating the catalyst of the bleaching agent, which releases nascent oxygen. About 30-60 mins are required at each visit. To get dramatic results several visits may be required. This is also a more expensive procedure. It may reduce the shade by 3-5 times lighter than the original shade.
      2. At-home vital bleach –It involves the use of custom-made polymerized resin trays with 10% carbamide peroxide incorporated into them. The patient is instructed to place enough bleaching agents into the trays to cover the outer surfaces of the teeth, after which excess bleaching material is wiped away. The tray should be worn for 4 hours for every session, following which the patient should thoroughly rinse off the teeth.
         Results can be seen as early as 2-4 days or may take 6-12 months.

3.Whitening Toothpaste
All toothpaste help remove surface stains because they contain mild abrasives. Some whitening toothpaste contains gentle polishing or chemical agents that provide additional stain removal effectiveness. Whitening toothpaste can help remove surface stains only and do not contain bleach; over-the-counter and professional whitening products contain carbamide peroxide or hydrogen peroxide that helps lighten the color deep in the tooth.

4.Over-the-Counter Whitening Strips and Gels
Whitening gels are clear, peroxide-based gels applied with a small brush directly to the surface of your teeth. Instructions generally call for twice a day application for 14 days. Initial results are seen in a few days and final results are sustained for about four months. Whitening strips are very thin, virtually invisible strips that are coated with a peroxide-based whitening gel. The strips are applied twice daily for 30 minutes for 14 days. Initial results are seen in a few days and final results are sustained for about four months.

1. Whitening Rinses
   Among the newest whitening products available are whitening rinses. Like most mouthwashes, they freshen breath and help reduce dental plaque and gum disease. But these products also include ingredients, such as hydrogen peroxide, which whiten teeth. Manufacturers say it may take 12 weeks to see results. You just swish them around in your mouth for 60 seconds twice a day before brushing your teeth. However, some experts say that rinses may not be as effective as other over-the-counter whitening products. Because a whitening rinse is only in contact with the teeth for such a short time — just two minutes a day compared to 30 minutes for many strips — it may have less of an effect