RESUMO
AIM: The aim of this in vivo study is to evaluate the antimicrobial efficacy of calcium hydroxide (Ca(OH)2), chlorhexidine (CHX), and metronidazole gel as intracanal medicaments against aerobic and facultative anaerobic microorganisms found in root canals of human primary teeth with necrotic pulp. SETTING AND DESIGN: It is a double-blinded randomized clinical trial. MATERIALS AND METHODS: Pulp canals of 45 single-rooted primary maxillary anterior teeth with pulp necrosis in 34 children were included in the study. They were divided into three groups of 15 samples each: Group I: Ca(OH)2; Group II: 1% CHX gel; and Group III: 1% metronidazole gel. Microbial count was obtained from each tooth at two different stages - (1) after instrumentation and (2) after placement of the medication. Statistical analysis using the SPSS 10.0 software program (SPSS Inc., Chicago, IL, USA) with Wilcoxon signed-rank test after grouping the samples was performed. RESULTS: Ca(OH)2, 1% CHX gel, and 1% metronidazole gel were ineffective in completely eliminating aerobic and facultative anaerobic microorganism from root canal of human primary teeth with necrotic pulp. CONCLUSION: None of the commonly used intracanal medicaments, that is Ca(OH)2, 1% CHX gel, and 1% metronidazole gel, was effective in completely eliminating aerobic and facultative anaerobic microorganism from root canal of human primary teeth with necrotic pulp. Ineffectiveness of these medicaments against aerobic and facultative anaerobic microorganism has opened new door of research regarding the manner of bacterial growth in unfavorable environmental and nutritional conditions, the way root canal environment favors biofilm formation and the use of suitable intracanal medicaments against single and multispecies biofilms.