RESUMO
INTRODUCTION: The aim of this study was to evaluate biofilm retention around orthodontic brackets related to the method of ligation by using optical coherence tomography (OCT) and microbiologic sampling. METHODS: Seventy-five plastic central incisors for dentures were divided into 3 groups and used with metal brackets with a 0.022-in slot with elastomeric ligature (n = 25), metal brackets with a 0.022-in slot with steel wire ligature (n = 25), and self-ligating brackets with a 0.022-in slot (n = 25). The samples were submersed in a suspension of Streptococcus mutans, genetically engineered to express green fluorescent protein, at 37°C for 72 hours to allow biofilm formation. The samples were then submitted to microbiologic analysis and OCT imaging. RESULTS: The microbiologic analysis and the OCT showed significant differences in biofilm formation depending on the ligating method. Brackets ligated with elastomeric rings held more S mutans biofilm, and steel wire ligation had less biofilm retention compared with the other brackets. CONCLUSIONS: This study provided validation that OCT can be used as a potential qualitative marker of total plaque bacteria that can be rapidly and reliably visualized around orthodontic brackets.