QUESTION: I have several patients who have undergone in-office bleaching and would like some over-the-counter options to upkeep their new white smiles. What do you suggest?
ANSWER: Although whitening is a scientific term for the color change of the tooth, the marketing world generally uses “whitening” to mean removing surface (extrinsic) stains without changing the internal color of the tooth, while “bleaching” is changing the internal (intrinsic) color of the tooth, as well as removing surface stains. Once the in-office bleaching is completed, the internal color of the tooth has been changed. Often the dental office sends the patient home with a tray and bleaching material so he or she can touch up the bleaching effect using either hydrogen peroxide or carbamide peroxide, or to treat tooth sensitivity with potassium nitrate. The tray approach is the most predictable but requires additional dental treatment and funds. Thermoplastic trays that can be made easily over the maxillary arch without an alginate impression are well-suited for continual bleaching without the higher cost of the impression-fabricated tray. Disposable bleaching trays with the peroxide bleaching product built into the tray can be very effective, as well. All of these approaches come from the dental office, and are generally part of the bleaching process.
The use of over-the-counter (OTC) products, such as whitening toothpastes and mouthrinses, can maintain the color change by continuing to remove the extrinsic surface stains, but they do not change the internal color of the tooth. With toothpastes, the surface stain removal is primarily by mechanical action and the abrasivity of the toothpaste, so you must use caution in a patient who has aggressive brushing habits. Whitening toothpastes are often more abrasive than normal toothpastes. Some toothpastes have additional ingredients to help dissolve stains or not allow them to stick, but many of the studies do not demonstrate a significant change, or they measure with a machine that records change that cannot be seen by the human eye. More important, the patient should evaluate what is causing the staining, such as smoking or diet. Continuation of these habits will cause a quicker regression of the color effect due to surface stains, which may gradually soak into the tooth and become intrinsic stains. Regardless of the products in the OTC toothpaste, the contact time and strength are not sufficient to change the internal color of the tooth; they only help avoid return of surface stains. Additionally, many other OTC products—such as activated charcoal, oil pulling, blue light kits, etc—have not proven effective and may be harmful, so they should not be encouraged. It would be more appropriate to use baking soda and OTC 3% hydrogen peroxide as a toothpaste, but this approach lacks fluoride and can be too abrasive. OTC whitening strips that contain a high concentration of hydrogen peroxide can bleach the teeth, although the treatment time is slower than other bleaching treatments, and gingival or tooth sensitivity is sometimes an issue. Some patients who already have a tray may use the strips in the tray when they no longer have the dentist-prescribed materials, as they are more comfortable to wear for longer periods and the strips conform better to the arch when pressed in by the tray. These strips can be used both to bleach and to remove surface stains.
Regardless of the approach, if the patient notices some significant tooth discoloration, he or she should return to the dental office for a re-examination and radiograph. Darkening teeth can be a sign of pathology, such as internal resorption or abscessed teeth, which requires a more aggressive treatment to avoid tooth loss.
The bottom line is that some products are “stain removers” and others are “color changers.” Each recommendation from the dental team must be tailored to the patient’s desires, finances, brushing habits, and esthetic expectations. Being monitored by the dental team to find the most reasonable approach that fits the patient’s lifestyle and wishes will be the most successful approach. Not every OTC product will be safe or effective in surface stain removal, but some can maintain a reasonable smile.
From Dimensions of Dental Hygiene. January 2019;17(1):46.