New “Parochip” Detects Periodontitis Fast and Leads to Early Detection

In the fight against gum disease (periodontitis), a new tool is making detection faster and easier than ever. The laser diode driven lab-on-a-chip is available to help detect the presence of some of the types of bacteria that causes the disease.

A new mobile diagnostic platform driven by a laser diode, it can identify the 11 most relevant periodontitis pathogens in less than 30 minutes rather than in the four to six hours it used to take.

Scientists at the Fraunhofer Institute for Cell Therapy and Immunology (IZI; Leipzig, Germany) have collaborated with two companies, BECIT GmbH (Wolfen Germany) and ERT-Optik (Ludwigshafen, Germany), to develop a lab-on-a-chip module called ParoChip

While currently available in prototype, in the future, this will allow dentists and medical labs to prepare samples quickly and then analyze the bacteria right in their own office.

All steps in the process–the duplication of DNA sequences and their detection—take place directly on the platform, which consists of a disk-shaped microfluidic card that measures around six centimeters in diameter.

The analysis is conducted in a contactless and fully automated manner. Samples are taken using sterile, toothpick-shaped paper points. Next the bacteria are removed from the point so their isolated DNA can be injected into reaction chambers containing dried reagents.

Eleven different chambers on each card allow them to feature the reagent for each one of the 11 periodontal pathogens. The total number of bacteria is determined in an additional chamber via polymerase chain reaction (PCR). PCR allows millions of copies of even tiny numbers of pathogen DNA sequences to be made.

In order to generate the extremely quick changes in temperature that is required for PCR, the disk-shaped plastic chip is attached to a metal heating block with three temperature zones and mechanically turned so it passes over these zones. This causes a fluorescent signal to be generated that is measured by a connected optical measuring device featuring a fluorescence probe, a photodetector, and a laser diode.

The key benefit is that the signal makes it possible not only to quantify each type of bacterium and thus determine the severity of the inflammation. The signal also establishes the total number of all the bacteria combined. This enables doctors to fine-tune treatment accordingly.

“As the connected optical measuring system allows us to quantify bacteria, ParoChip is also suited to the identification of other bacterial causes of infection, such as food-borne pathogens or those that lead to sepsis,” says Dirk Kuhlmeier, a scientist at the IZI. “Using ParoChip does away with many of the manual steps that are a necessary part of current bacteria tests. The synthetic disks can be produced cheaply and disposed of after use in the same way as disposable gloves.”

Already available as a prototype, ParoChip is initially intended for use in clinical laboratories; however, it could also be used by dentists to carry out in-house analysis of patient samples in their own practice.

Dentists use sterile paper points to remove bacteria from the tooth for bacterial analysis to detect periodontitis. (Image courtesy of Fraunhofer IZI)

This new, easy to use tool will be available to us for early detection of bacteria that cause periodontitis. Early detection can allow us to treat periodontitis minimizing the impacts of the disease on patients’ oral health as well as other chronic diseases that have been associated with periodontitis.