Assessment of the endodontic microbiota of abscessed primary teeth using microarray technology

Context: Knowledge of the microbial composition of abscessed primary tooth is limited. Aim: The aim was to investigate the presence of 10 oral bacterial species in samples from abscessed primary tooth root canals using microarray technology and to determine their association with clinical findings. Subjects and Methods: The samples were collected from root canals of 20 primary molars with acute primer infection. The bacterial composition of the samples was semi-quantitatively defined using a microarray system (ParoCheck®). Clinical parameters included the presence of spontaneous pain, mobility, percussion sensitivity and swelling. Statistical Analysis: Data were statistically analyzed by Student' t-test, Fisher's exact Chi-square test, Freeman–Halton–Fisher's exact test, and Spearman's rho correlation analysis. Results: All the tested species were detected in the samples. Fusobacterium nucleatum was the most frequent bacterium (100%), followed by Parvimonas micra (65%), Provetella intermedia (45%), and Treponema denticola (45%). According to paired bacterial combinations, F. nucleatum was significantly positively correlated with P. intermedia and P. micra (P < 0.05). T. denticola was significantly positively correlated with Porphyromonas gingivalis, Tannerella forsythia, Campylobacter rectus, and P. micra, while it was negatively correlated with Eikenella corrodens (P < 0.05). No statistically significant relationships were found between the presence of any bacteria and clinical findings. Conclusion: Microarray technology used in this study has demonstrated the presence of various bacteria with varying proportions in the root canals of abscessed primary teeth. The results regarding the high rate of certain bacterial combinations suggest the enhanced pathogenicity due to additive or synergistic effects of these microbial combinations.