Incubating caries bacteria in the cooled incubator

60 – 90 % of schoolchildren and the majority of adults in industrial countries suffer from caries, according to the WHO (World Health Organization). The paediatric dentistry department at the Gießen site of the University Clinic of Giessen and Marburg, location Giessen, has declared war on this worldwide plague and is doing intensive research under the direction of Professor Dr. Dr. Norbert Krämer to extend tooth life. One important resource is a fully-automated artificial oral cavity, which can simulate how caries develops in a simple and above all accelerated manner. During the experiments the caries model is stored in a Memmert IPS storage chamber.

Safely incubating even at high ambient temperatures

The artificial oral cavity was developed by Dr. Claus Fuchs (né Ritzmann) in 2008 during his doctorate “An automated caries model to generate secondary carious lesions”, for which he was awarded the Sponsorship Prize for Young Scientists by the Free Association of German Dentists in 2009. Professor Norbert Krämer, Director of the Polyclinic for paediatric dentistry at the University Clinic of Giessen and Marburg, explains: “Artificial saliva, caries pathogens and culture media are selectively fed into the model by means of a system with automatically controlled pumps. Depending on various parameters such as the number of “meals” or acid attacks, we can produce artificial secondary caries on the marginal gaps between filling and tooth. The experiments are used not for research into caries, but to test filling materials and adhesives. Before the teeth are inserted into the caries model, they are subjected to a thermal alternating treatment with a temperature difference of 50 °C. After this; we measure the marginal gaps that occur between the tooth and the filling and analyse the development of demineralisation.”

The temperature for incubating the caries bacteria in the incubator is a constant 37 °C, but since temperatures of over 35 °C can occur in summer in the relatively moderate climate zone around Giessen and Marburg, the search was on for an incubator which in this case would reliably cool down.

Peltier elements make the cooled incubator immensely reliable

Thanks to the integrated Peltier elements for cooling the interior of the IPS cooled incubator, the caries bacteria at the University Clinic of Gießen and Marburg do not break into a sweat, even at high temperatures. A reliable and precise incubation at room temperature is guaranteed. “Even after opening the doors, the temperatures in the chamber recover extremely quickly,” explains laboratory director Dr. Susanne Lücker, and she mentions the inner volume of 749 litres and the inner glass doors as further benefits of the IPS cooled incubator. To introduce the tubes from the supply containers for saliva and culture media into the caries model, openings were drilled at various points into the housing for this customised model from Memmert.

AtmoSAFE thanks the Polyclinic for Paediatric Dentistry at the University Clinic of Giessen and Marburg for their friendly support in writing this article.