Symptomatic and asymptomatic apical periodontitis associated with red complex bacteria: clinical and microbiological evaluation

TLDR: Generally, RC bacteria were associated with pain and a higher frequency of intracanalar/intrasulcular pus drainage and should be suspected in the presence of particularly severe clinical pain and pus drainage.

Abstract: In this study, the association of red complex (RC) bacteria that include Treponema denticola, Tannerella forsythia and Porphyromonas gingivalis with acute, exacerbated or chronic apical periodontitis was evaluated. Seventy-one patients with periapical disease were evaluated by clinical examination and microbiological samples obtained from the root canals were analyzed by a polymerase chain reaction assay. Twenty-one (29.6%) samples were positive for RC bacteria, with T. denticola, T. forsythia and P. gingivalis being detected in 14 (19.7%), 10 (14.1%) and 6 (8.5%) samples, respectively. RC bacteria were mainly associated with acute apical periodontitis (29.2%) and phoenix abscess (63.2%), while they were only sporadically detected (7.1%) in patients with chronic apical periodontitis. Generally, RC bacteria were associated with pain and a higher frequency of intracanalar/intrasulcular pus drainage. Involvement of RC bacteria in symptomatic periapical disease should be suspected in the presence of particularly severe clinical pain and pus drainage.