Light meters are an essential tool for anyone who calibrates light-producing or light-sensing equipment. From indoor and outdoor digital displays to photography and even to indoor lighting, a professional-quality light meter should factor in any and all calibration systems.

Many foods and drinks today have negative side effects on our teeth. From high-acid content that erodes enamel and can cause increased wear on our teeth, beverages such as wine, as well as smoking and other nicotine-containing products many of these products also cause our teeth to appear dull or even yellowed. In recent years however many companies have released products that promise to not only clean the residue off of our teeth but, also, to turn back the clock and make them appear whiter and brighter and there are two primary methods for achieving this whitening effect:

• Some toothpastes use abrasive materials which literally attempt to scrub off layers of foods and drinks that are staining the teeth. The problem with these products, however, is that not only do they achieve minimal results compared to out-of-pocket expense but, also, they tend to cause irreversible damage to the teeth and gums over a prolonged period of use.

• Other toothpastes make use of special enzymes that build a layer on the tooth which prevents further stains from forming. Unfortunately, these products are unable to actively reduce the level of stains on teeth and are only protective rather than active in stain-fighting.

Recently, however, some companies have released products which claim to be "professional strength" and that use similar techniques as professional tooth-whitening services. While this is true, most professional services use a solution of hydrogen peroxide and a powerful light to not only clean but also to protect teeth, these commercial products tend to be significantly less powerful than their professional-strength cousins and, as a result, achieve minimal effects when compared to their costs.

To better demonstrate the effectiveness, or lack of effectiveness, of these commercial tooth-whitening products their effects can be measured using a spectrophotometer which is a device commonly used in chemistry and engineering applications. A spectrophotometer measures either the reflection or the transmission of light from a surface or object and, in the case of tooth-whitening products, could be used to test differences in reflectance before and after treatments has been administered. The process would be simple and could be performed quite simply:

• First, a sample material with qualities similar to that of human teeth could be exposed to staining materials such as wine and coffee. Then, after the sample material has achieved a similar level of staining to that of an average tooth-whitening customer, its reflective properties can be measured using a spectrophotometer.

• After the readings have been recorded, the sample material can have a tooth-whitening treatment applied to it and can be tested again. This test can be repeated multiple times over the recommended course of treatment for the tooth-whitening product.

• After each treatment is applied, new readings can be taken and recorded. Over time any changes in these readings will show the strength of results achieved from the product.

• Finally, multiple samples can be used against multiple treatment options to verify the effectiveness not only of commercial tooth-whitening solutions but, also, of professional solutions as well.

Regardless of the reason toot-whitening is desired, it's always best to consult with a dentist before undertaking any oral care regimen. The dentist can evaluate what is causing the wear and staining of teeth and can recommend the best course of treatment.

Author: Paul is a freelance writer interested in Konica Minolta spectrophotometers which is used for color measurement. For more information visit Konica Minolta.