Short-term effects of fixed orthodontic appliance on concentrations of mutans streptococci and persister cells in adolescents

Chelsea Ko-Adams; Iacopo Cioffi; Delphine Dufour; S M Hashim Nainar; Céline M Lévesque; Siew-Ging Gong

doi:10.1016/j.ajodo.2019.04.033

Short-term effects of fixed orthodontic appliance on concentrations of mutans streptococci and persister cells in adolescents

Am J Orthod Dentofacial Orthop. 2020 Mar;157(3):385-391. doi: 10.1016/j.ajodo.2019.04.033.

Authors

Chelsea Ko-Adams¹, Iacopo Cioffi¹, Delphine Dufour², S M Hashim Nainar³, Céline M Lévesque², Siew-Ging Gong⁴

Affiliations

¹ Orthodontics program, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada.
² Oral Microbiology program, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada.
³ Pediatric Dentistry program, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada.
⁴ Orthodontics program, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada. Electronic address: sg.gong@dentistry.utoronto.ca.

PMID: 32115117
DOI: 10.1016/j.ajodo.2019.04.033

Abstract

Introduction: 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.

Methods: 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.

Results: 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.

Conclusion: 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.

MeSH terms

Adolescent
Child
Dental Caries* / microbiology
Dental Plaque*
Female
Humans
Male
Orthodontic Appliances
Orthodontic Appliances, Fixed* / microbiology
Saliva
Streptococcus mutans* / isolation & purification