Bacteriology of chronic apical periodontitis after using intracanal medication

Abstract

The objective of the study was to evaluate the antibacterial effect of different intracanal medication: 1% sodium hypochlorite, calcium hydroxide paste, 2% chlorexidi- ne and camphorated paramo- nochlorophenol. The endodontic treatment was achieved and the tooth remained with the intraca- nal medication for 7 days. After this period, the tooth was isolated with rubber dam and sterile sa- line solution was introduced and aspirated from the root canal. The aspirated material was spread in culture media composed by blood agar, MacConkey, azide blood agar (to identify aerobes), bru- cella blood agar, FEAS and thio- glycolate (to identify anaerobes). The incubation and identification was achieved at Hospital de Clín- cas de Porto Alegre (HCPA) – Mi- crobiology Unit. In this study, we found 100% of negative cases for anaerobes with the four tested medication. For the aerobic micro- organisms, we got 100% of negati- ve cases using calcium hydroxide, followed by 2% chlorexidine (60% negative culture cases) and cam- phorated paramonochlorophenol (60% negative culture cases). 1% sodium hypochlorite presented 100% of positive culture cases for aerobic microorganisms. The pre- dominant aerobic microorganisms were: Klebsiella oxytoca, Strep- tococcus sp. alpha hemolytic, En- terococcus sp., Enterobacter sp., Streptococcus sp. (viridans group), Streptococcus sp. anemolytic and Escherichia coli. We verified, in this study, that calcium hydroxide paste, 2% chlorexidine and para- monochlorophenol show antimi- crobial effect. Key words: chronic periapical os- teitis, bacteriology, intracanal medication, temporary filling.