An In Vitro Model for Evaluating Bacterial Leakage Through Endodontic Repair Materials

The leakage of bacteria through endodontic repair materials is a matter of great concern in dentistry, as the success of repair of furcation perforations or root ends lies in the seal provided by the material against bacterial infiltrations. In vitro microleakage techniques (like dye penetration and fluid filtration) are used to assess the sealing ability of repair materials. However, such microleakage results cannot be correlated with migration of microbes in real situations. The quest for obtaining clinically relevant data prompted researches to develop bacterial leakage models. Various custom set ups had been developed for the purpose. We report a new model for studying bacterial leakage through repair materials, which could be applied universally for teeth of any size and shape. It consists of a cast of the repaired tooth in poly methyl methacrylate (PMMA), incorporated in microbiological test set up. The cast is modified to get a delivery chamber in the upper portion and the lower portion is appropriately sized to allow the repaired part come in contact with the culture medium. The inoculum is delivered to the upper chamber and the leakage of the bacteria is identified through the colony formation in the medium. This model is close to clinical condition and provides reliable and repeatable results. Minimum error parameters, ease of working and reliability are additional features.