Stained or yellowing teeth are an unfortunate part of aging. Certain medications and lifestyle choices such as smoking, drinking, and diet effect the color of your teeth as well. For example, those who consume wine and coffee on a regular basis are more likely have yellow teeth than those who do not drink such teeth staining liquids.

The desire to have a healthy white smile has generated an array of whitening products; from mouthwashes, toothpaste, strips and trays. While the professional cleanings at the dentist office may produce the best results, they are also the costliest.

A product that maybe closest to a professional treatment, are LED whitening kits. These kits combine a whitening gel with a light source. The added light is supposed to accelerate the time and intensity of this whitening treatment, mimicking the laser or UV light source that has been used in a dental office.

First it might be helpful to recognize that not all stains are the same. And some may require professional treatment.

Intrinsic and Extrinsic Stains

The degree and type of tooth discoloration or staining is an important factor, not only for the product or treatment used, but how long it might last.

• Intrinsic stains are caused by aging, trauma, infection or medication. These can be deep internal stains that are harder to eliminate, and may require professional dental procedures to be removed.
• Extrinsic stains are caused by substances your intake, such as smoke, food and drink. Most whitening products are designed to work on this type of stain.

What we know is that most LED whitening devices comes with a bleaching agent, usually hydrogen peroxide or carbamide peroxide which turns into hydrogen peroxide. These chemical bleaching agents work with or without an LED light source. This is primary solution found in most whitening products, from whitening mouthwash or toothpaste to professional whitening procedure performed in dental office. How they are different is the concentration of hydrogen or carbamide peroxide in the bleaching agent. Dentist may use a significantly stronger concentration, in the area of 43% if needed, while the consumer products fall between the 3% to20% range, with most at lower end.

Bleaching (using peroxides) tend to be the quickest and most effective way to lighten the color of teeth.  Bleach actually penetrates the enamel to address the internal color, altering it through a chemical and physical reaction. Actually, the bleach opens pores in the tooth enamel to allow the bleaching agent to seep through to get to the dentin. At the dentin layer, the bleach breaks down the stain into smaller particles, making the stain less concentrated, leaving your teeth whiter.

The stronger the bleaching agent the whiter the teeth, but these higher concentrations require an evaluation of present teeth health and precautions so they are confined to the dental office, and are not available, as stated above, to the consumer.

In recent time use of UV light for some oral application has been replaced by LED lights. Reportedly LED lights can provide the catalytic effect for the beaching agent chemical reaction without the added risk of radiation.  But is this backed by research, do LED lights augment the bleaching agent?

What we don’t know

Is whether this claim is justified or not? There are many studies done in this area, and there are a lot of conflicting views. One of the most thorough review of published paper from 2003 to 2013 that address the addition of a “light- activation” source on tooth whitening concluded that they DO NOT work. Dr. Baroudi states, “the use of light activator sources… did not increase the efficacy of bleaching or accelerate the bleaching.” {2} This report also highlighted that contact time (how long bleaching gel was on the teeth) was the second most critical factor in achieving the desired whiteness.

But even in this review there were a few (not most) dissenting viewpoint and studies that did conclude that various light sources from laser to halogen to plasma arc lamps do accelerate the beaching process.

Two recent studies are on the side of light activating techniques, reporting significant results but both studies used lasers as their light source. (3,4}

Research is not clearly answering this question, since there are so many conflicting studies, but there seems to be some noteworthy results when using lasers as a light source. (Particularly for dental whitening where dentine sensitivity from high peroxide concentration is a frequent complaint, lasers may help to resolve this issue.)

Are there side effects with LED whitening?

• Sensitivity Your teeth may become more sensitive after LED teeth whitening. This is typically not long lasting. If sensitivity does occur it might be beneficial to use a soft toothbrush immediately after.
• Gum Irritation If the bleaching agent comes in contact with the gums, it can cause irritation. This like tooth sensitivity is usually temporary, and should subside in a few days. It should be noted that the bleaching agent can also lighten the color of the gum but again not a permanent side effect.
• Overuse Repeated tooth whitening, using too much whitening agent or leaving it on longer than recommended can damage the teeth. All of these issues can be avoided by adhering to the kit instruction.

Hype or no hype

A lot of dentist dismiss the LED consumer lights found in the whitening kits, noting they are not strong enough to produce a catalytic reaction, so they don’t replicate the light activating method used in dental offices.

Most of viable research from these studies did not use consumer LED lights but professional dental lights and there is still conflict if these in fact are effective.

Not all kits are the same, but this is more about strength of whitening gel and the length of contact time. However, some kits taut that their LED light is not used as a catalysis but rather it helps to adhere the whitening agent to the teeth.

LED teeth whitening does work because of the whitening agent, but how beneficial the actual LED light component is lost in the hotly contested discussion if any light activating source increases the efficacy of teeth whitening.