Abstract
The aim of this investigation was to examine the presence of 8 bacterial anaerobic species in endodontic samples from patients with primary and secondary infection. The association of clinical signs and symptoms with constituent species were also evaluated. Microbial samples were obtained from 72 teeth with primary endodontic infection and 35 teeth with secondary endodontic infection. DNA was extracted from samples and analyzed with a polymerase chain reaction (PCR)-based identification assay. Medical and dental histories were obtained from each patient. The prevalence of the targeted bacterial species was recorded for each case and descriptive statistical analyses were performed using the Pearson Chi-squared test. Nucleid acid amplification method (NAAM) analysis showed that all specimens were positive at least for 1 or more samples in primary and secondary infection teeth. The most frequently detected bacteria in all speciemens were Porphyromonas gingivalis, followed by Porphyromonas micros, Porphyromonas endodontalis, Fusobacterium nucleatum, Porphyromonas intermedia and Tannerella forsythia, respectively. The percentages of all selected bacteria found in primary infection group were higher than secondary infection group except for Porphyromonas intermedia. However, statistically significant difference was found only for T. forsythia and F. nucleatum which were higher percentage in primary infection than in secondary infection group. There was a significant association between tenderness to percussion and P. gingivalis (p < 0.05), pain with Porphyromonas melaninogenica (p < 0.05) and swelling with both P. gingivalis (p < 0.05) and P. melaninogenica (p < 0.05). Findings indicated that the prevalence of some species found in the primary infection group were higher than in the secondary infection group. In this study there was a significant association between tenderness to percussion and P. gingivalis, pain with P. melaninogenica and swelling with both P. gingivalis and P. melaninogenica. Key words: Primary endodontic infection, secondary endodontic infection, anaerobic bacteria, nucleid acid amplification method (NAAM).
Highlights
Apical periodontitis is caused by bacteria of infected root canals (Kakehashi et al, 1965)
It is well known that most periodontal pathogens like P. gingivalis and P. endodontalis are endodontic pathogens which are the key organisms in adult periodontitis and frequently found in root canal infections
The percentage of all selected bacteria found in the primary infection group was higher than the secondary infection group except for P. intermedia
Summary
Apical periodontitis is caused by bacteria of infected root canals (Kakehashi et al, 1965). The microbial flora in secondary endodontic infections have been described as monoinfections or infections including a few Gram-positive bacterial species, with approximately equal proportions of facultative and obligate anaerobes (Sundqvist et al, 1998; Pirani et al., 2008). Infections of the root canal system with facultative and obligate anaerobic bacteria have been associated with different clinical signs and symptoms (Jung et al, 2000; Gomes et al, 2004; Siqueira et al, 2004; Cavrini et al., 2008). Significant associations were found between individual clinical features and the following pairs of species: Peptostreptococcus spp., Prevotella melaninogenica, P. micra are associated with pain, P. micra and Prevotella spp. is associated with swelling and Prevotella spp., Eubacterium spp. and Peptostreptococcus spp. are associated with wet canals (Gomes et al, 1996). P. melaninogenica and P. micra is associated with pain and swelling (Drucker, 2000)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
