title: A computational fluid dynamic analysis of peri-bracket salivary flow influencing the microbial and periodontal parameters.
abstract: Fixed vestibular appliances decrease the "self-cleansing" action of saliva and promote aggregation of dental plaque by disturbing the salivary flow field on tooth surfaces, leading to a higher prevalence of enamel demineralization and periodontal diseases. In the current study, we investigated the salivary dynamic characteristics of plaque retention and periodontal status around appliances during orthodontic treatment. By reconstructing lower central incisors and orthodontic appliances, we simulated saliva flow on the tooth surface and then characterized and quantified the salivary flow pattern surrounding the bracket and archwire. In parallel, we tested the total peri-bracket bacterial counts and periodontal status to assess interrelations. Our results demonstrate that orthodontic appliances disturb the salivary flow field on tooth surfaces and can lead to a decrease in salivary velocity and an increase in bacterial numbers. Local vortexes forming in the areas gingival to the bracket, together with the narrow space limitation, contributed to the periodontal inflammatory response. This study confirms that changes in salivary flow are an obvious predisposing factor for bacterial accumulation, and advances the ability to replicate, in vitro, the salivary characteristics of plaque retention and periodontal status around appliances during orthodontic treatment.
authors.affiliation: Department of Orthodontics, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, Guangdong, PR China.
authors.forename: Ping
authors.initials: P
authors.lastname: Zhu
authors.forename: Han
authors.initials: H
authors.lastname: Lin
authors.forename: Yi
authors.initials: Y
authors.lastname: Han
authors.forename: Yi
authors.initials: Y
authors.lastname: Lin
authors.forename: Yue
authors.initials: Y
authors.lastname: Xu
authors.forename: Zhaoqiang
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D001419:Bacteria / Q000166:cytology; D015169:Colony Count, Microbial; D003198:Computer Simulation; D005260:Female; D006801:Humans; D057446:Hydrodynamics; D007180:Incisor / Q000502:physiology; D008297:Male; D016910:Orthodontic Brackets / Q000382:microbiology*; D009969:Orthodontic Wires / Q000382:microbiology; D010519:Periodontium / Q000382:microbiology / Q000502:physiology*; D012463:Saliva / Q000382:microbiology* / Q000502:physiology*; D012472:Salivation / Q000502:physiology*; D055815:Young Adult