Orthodontics program, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada.
Oral Microbiology program, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada.
Am J Orthod Dentofacial Orthop. 2020 Mar;157(3):385-391. doi: 10.1016/j.ajodo.2019.04.033.
Orthodontic patients are at an increased risk for developing caries. Dental caries is a biofilm-mediated disease, with mutans streptococci (MS) as the primary etiologic bacterial group. It has been suggested that persister cells (PCs), a subset of cells within the biofilm, contribute to the chronic infectious nature of dental caries. PC formation can be induced by environmental stressors such as orthodontic treatment. The aim of this study was to quantify MS, aerobic and facultative anaerobe bacterial PC proportions from plaque samples during the initial stage of orthodontic treatment. This study is the first to analyze the role of PCs in a population of patients highly susceptible to caries, that is, patients undergoing orthodontic treatment.
Plaque samples were collected from 17 participants (11 males and 6 females; age range: 11-18 years) before and 1 month after insertion of fixed orthodontic appliances. Percentages of MS and PCs were determined with selective media and a classical persister microbial assay, respectively.
There was a statistically significant decrease in %MS (P = 0.039) but no statistically significant difference in %PCs (P = 0.939) after 1 month of orthodontic appliance placement.
Our study illustrated the technical feasibility of analysis of PCs in plaque samples of patients during orthodontic treatment and revealed that PC formation during orthodontic treatment is highly variable across individuals.
正畸患者发生龋齿的风险增加。龋齿是一种生物膜介导的疾病，变形链球菌（MS）是主要的病因细菌群。有人提出，生物膜内的一个亚群——持久细胞（PC）有助于龋齿的慢性感染性质。PC 的形成可由正畸治疗等环境应激源诱导。本研究旨在定量分析正畸治疗初始阶段菌斑样本中 MS、需氧和兼性厌氧菌 PC 的比例。这是首次在对龋齿高度易感的人群（即接受正畸治疗的患者）中分析 PC 的作用的研究。
在固定正畸矫治器插入前和插入后 1 个月，从 17 名参与者（11 名男性和 6 名女性；年龄范围：11-18 岁）的菌斑样本中采集。使用选择性培养基和经典持久微生物测定法分别确定 MS 和 PC 的百分比。
正畸矫治器放置 1 个月后，MS 的百分比（%MS）呈统计学显著下降（P = 0.039），但 PC 的百分比（%PCs）无统计学显著差异（P = 0.939）。
我们的研究说明了在正畸治疗期间分析菌斑样本中 PC 的技术可行性，并表明正畸治疗期间 PC 的形成在个体之间高度可变。
