Winner of the 2006 Research Award

Canada – 04 June, 2008

Title: Development of an ex-vivo model for quantification of root canal bacteria during endodontic treatment.

Principal Investigator: Dr. Gaelle Villette
Supervisor: Dr. Bettina Basrani
Institute: University of Toronto School of Dentistry

Abstract of winning proposal:

Quantification of root canal bacteria to assess efficacy of antibacterial regimens requires inactivation of medications and sampling procedures that inconvenience patients and treatment providers. This study aims to develop an ex-vivo model that would allow bacterial quantification in simulation of clinical conditions. Immediately after extraction, 36 teeth will be stored in a humidified incubator for 24h, 2d, 4d or 7d (n=9). They will then be accessed, bacteriological samples obtained from canals (S1), and sealed. After further incubation for 1 week, canals will be sampled upon re-access (S2) to assess bacterial survival, and sampled again after cleaning and shaping (S3). After further incubation for 1 week, canals will be sampled upon re-access (S4) to assess bacterial re-growth in the absence of medication. Canal samples will be acquired by aspiration, preceded by surface disinfection of teeth and sampling of access cavities. Sampled bacteria will be enumerated using CFU counts and vital microscopy. Bacterial concentrations will be calculated and compared among the different samples in one group and between the 4 groups using a paired and unpaired t-test.