Rôças, Siqueira Jr pathogen. This species has been associated with failed to disclose C. pneumoniae in any of the end- gastritis and peptic ulcers, and may represent a odontic samples examined. risk factor for gastric cancer.2 It has been shown If H. pylori and C. pneumonia are present in the that approximately 50% of the world’s population oral cavity, both species might be able to survive is infected with H. pylori.2-4 Overt clinical disease is in the necrotic root canal and then participate in found in about 5-10% of the infected individuals.5 the pathogenesis of apical periodontitis. Moreover, Several researchers have suggested that the the necrotic root canal might act as a reservoir for oral cavity may serve as the primary extragastric these important human pathogens to exert system- reservoir for H. pylori.6-14 Actually, H. pylori has ic effects. The present study was undertaken to sur- been detected in samples from saliva,7,10,13,15-16 su- vey samples of primary endodontic infections from pragingival biofilms,8,16-17 subgingival biofilms,6-8,16 healthy patients for the presence of H. pylori and C. and tongue dorsum.16 At the time of writing, no pneumoniae. study had yet investigated the occurrence of H. py- lori in samples of endodontic origin. MAtErIALs And MEtHods Chlamydia pneumoniae is a spherical or ovoid The study protocol was approved by the Ethics obligately intracellular bacterial pathogen. This Committee of the Estácio de Sá University, Rio de species is gram-negative in architecture and Janeiro, Brazil. Samples were taken from patients composition, with an outer membrane containing who had been referred for root canal treatment or lypopolysaccharides. However, chlamydia appar- emergency treatment to the Department of End- ently lacks peptidoglycan, even though genes for odontics, Estácio de Sá University. Only single- synthesis of this molecule have been identified in rooted teeth from adult patients (ages ranging from their genome. In the extracellular environment, 18 to 74 years), all of them having carious lesions, chlamydiae occurs in an infective or dispersal form necrotic pulps and radiographic evidence of apical called elementary body, while within cells they ex- periodontitis, were included in this study. Select- ist in a replicative form called reticulate body.18 ed teeth showed an absence of periodontal pock- C. pneumoniae is one of the leading pathogens of ets deeper than 4 mm. In general, 50 samples of community-acquired pneumonia,19 and has been primary endodontic infections were obtained: 25 associated with pharyngitis, sinusitis, and bron- asymptomatic cases diagnosed as chronic apical chitis.20 There is suggestive evidence that infection periodontitis and 25 cases diagnosed as acute api- with this species and dental infections may be as- cal abscesses, which showed pain and localized or sociated with atherosclerosis.21 diffuse swellings along with fever, lymphadenopa- C. pneumoniae has been rarely found to infect thy, or malaise. No apparent communication from oral tissues. Tran et al22 used a species-specific the abscess to the oral cavity or the skin surface 16S rRNA gene-based polymerase chain reaction was observed. Patients reported no gastric diseas- (PCR) identification method and did not find C. es and no other significant systemic condition. Pa- pneumoniae in any samples from subgingival bio- tients who have taken antibiotics over the previous films from 50 adult patients with advanced mar- 3 months were excluded from the study. ginal periodontitis. C. pneumoniae has been identi- In cases of chronic apical periodontitis, samples fied in the oropharynx, possibly involved with about were obtained from the root canals using sterile 9% of cases of pharyngitis.23 Mantyla et al24 sought paper points. After the tooth crown was cleansed C. pneumoniae in subgingival biofilm samples from with pumice, rubber dam was placed and the tooth adults with marginal periodontitis and found this and the surrounding field were cleansed with 3% species in only one out of 12 patients using a quan- hydrogen peroxide and disinfected with a 2.5% Na- titative PCR technique. To the best of our knowl- OCl solution. Caries was removed and the access edge, only one previous study surveyed endodontic cavity was prepared. The operative field, including samples for the presence of C. pneumoniae. Nan- the pulp chamber, was again swabbed with 2.5% dakumar et al25 evaluated samples from primary NaOCl, which was then inactivated by sterile 5% so- and persistent/secondary endodontic infections of dium thiosulphate. If the root canal was dry, a small 40 patients for the presence of C. pneumoniae us- amount of sterile saline solution was introduced ing single and nested PCR assays. Both methods into the canal. Samples were initially collected by April 2012 - Vol.6 159 European Journal of Dentistry