Chennai: Detecting the first signs of dental caries that afflicts at least 90 percent of the global population at one time or the other has now become easier, thanks to researchers in Tamil Nadu.

R. Siva Kumar of RMK Engineering College explained that dental caries, known as tooth decay or dental cavities, damages the structures of the teeth, besides causing toothache, tooth loss, infection of the jawbone and beyond, and in severe cases, death.

RMK researchers have now developed an X-ray image analysis technique that reveals the pixel intensities at different X-ray wavelengths, much like the histogram analysis of images by a high-specification digital camera.

Siva Kumar explained that the software reveals that the X-ray histogram and spectrum are very different, depending on whether the teeth X-rayed are normal or exhibiting early stages of decay.

The researchers found that in the X-ray histogram the pixel intensities are concentrated in different ranges depending on degree of decay.

The technique could be very useful for dental clinicians, the researchers explained, and could be extended using neural networks to automatically identify the different stages of dental caries.

Detecting caries in the early stages is important for saving affected teeth and avoiding the possibility of tooth loss and invasive surgery at later stages.

Caries are caused by acid-producing bacteria that feed on fermentable carbohydrates including sucrose, fruit sugars, and glucose. The higher level of acidity in the mouth due to this bacterial activity effectively dissolves the mineral content of the tooth.

There are two types of dental caries, those that form on the smooth surfaces of the teeth and those in the pits and fissures. The latter are difficult to detect visually or manually with a dental explorer.

In the US, dental caries is the most common chronic childhood disease, being at least five times more common than asthma. It is the primary cause of tooth loss in children, while between a third and two thirds of people over 50 years experience caries too.

These findings appeared in the latest issue of the International Journal of Biomedical Engineering and Technology. IANS