Microbial profile of root canals of primary teeth with pulp necrosis and periradicular lesion.

Purpose: The purpose of this study was to assess the microbial content of root canals of human primary teeth with pulp necrosis and periradicular lesion.

Methods: Microbial samples were collected from 24 canals of children treated at a pediatric dentistry clinic. Microbiological identification was performed using checker-board DNA-DNA hybridization for 40 different bacteria. Data were analyzed per canal based on the mean count and frequency of each bacterial species.

Results: Detectable levels of bacterial species were observed for 35 probes (88%). The most frequent bacteria were Fusobacterium nucleatum sp. nucleatum, Fusobacterium periodonticum, Prevotella melaninogenica, Prevotella nigrescens, and Prevotella intermedia. Facultative species were identified in 20 root canals (83%), anaerobic species were identified in 24 root canals (100%), and aerobic species in 18 root canals (75%). Black-pigmented bacilli were found in 23 samples (96%). The number of different bacterial species detected per canal ranged from five to 33.

Conclusion: Endodontic infection in primary teeth with pulp necrosis and periradicular lesion is multimicrobial, including aerobic, facultative, and anaerobic micro-organisms.