Preliminary study of the presence and association of bacteria and archaea in teeth with apical periodontitis
Article first published online: 11 NOV 2009
© 2009 International Endodontic Journal
International Endodontic Journal
Volume 42, Issue 12, pages 1096–1103, December 2009
How to Cite
Jiang, Y. T., Xia, W. W., Li, C. L., Jiang, W. and Liang, J. P. (2009), Preliminary study of the presence and association of bacteria and archaea in teeth with apical periodontitis. International Endodontic Journal, 42: 1096–1103. doi: 10.1111/j.1365-2591.2009.01639.x
- Issue published online: 11 NOV 2009
- Article first published online: 11 NOV 2009
- Received 24 August 2008; accepted 1 September 2009
- root canal infections;
Aim To investigate, by reverse transcription polymerase chain reaction (RT-PCR), the presence and association of bacteria and archaea in primary and secondary root canal infections.
Methodology A total of 77 root canal samples from 77 Chinese patients, 42 with necrotic pulp tissues (primary infection) and 35 with failed prior conventional root canal treatment (secondary infection), aseptically exposed at the first patient visit, were studied. Total RNA was isolated directly from each sample, and 16S rRNA gene-based RT-PCR assays were used to determine the presence of bacteria and archaea, respectively.
Results Bacteria were detected in 39/42 (93%) of root canal samples from teeth with primary infections, and archaea in 16/42 (38%). In the cases diagnosed as secondary root-infected canals, bacteria were detected in 30/35 (86%), whilst archaea were detected in 6/35 (17%) of cases. Amongst the canals, which were positive for bacteria, archaea were always found in combination with bacteria. The incidence of symptomatic cases positive for both bacteria and archaea (16/22, 73%) were significantly higher than those positive for bacteria alone (21/47, 45%) (P < 0.05).
Conclusions This study confirms the presence of archaea in root canal infections and further implicates them in an association with clinical symptoms. The nature of this association requires further study.