Aerobic microbiota prevalent at the biofilm of Haas palatal expanders

Objectives: This study evaluated the aerobic and anaerobic facultative microbiota prevalent at the biofilm of the Haas palatal expander of 11 patients, ageing between 8 to 14 years old, in both sexes. Methods: After expander removal, biofilm was collected, weighed, dispersed in ultrasound bath, diluted and plaqued in specific culture media for total oral streptococci (TS), mutans streptococci (MS), lactobacilli (TL), staphylococci, yeast, pseudomonades and coliforms. Results: The results showed a superior participation of gram-positive (except for staphylococci) in the microbiological composition of the biofilm (p ≤ 0.05). Additionally, a positive correlation was observed between the counts of TS, MS and TL and the total biofilm mass (p ≤ 0.05), as well as a positive correlation between the counting of MS and TS (p ≤ 0.05). Conclusion: It was concluded that mutans streptococci and lactobacilli are the most prevalent aerobic and anaerobic facultative at the biofilm associated to the Haas palatal expander.