title: Evaluation of home disinfection protocols for acrylic baseplates of removable orthodontic appliances: A randomized clinical investigation.
abstract: BACKGROUND
  In this randomized clinical trial, we investigated, using the microbial culture technique and scanning electron microscopy, the contamination of acrylic baseplates of removable orthodontic appliances by mutans streptococci (MS) and evaluated the efficacy of different home disinfection protocols with a 0.12% chlorhexidine gluconate spray (Periogard, Colgate-Palmolive, São Bernardo do Campo, Brazil).
  
  
  METHODS
  Fifteen dental students were randomly enrolled in a 3-stage changeover system with a 1-week interval between each stage. The acrylic baseplates were worn full time except at meals to simulate the routine use of removable appliances under clinical conditions. Three 1-week home disinfection protocols were tested in all stages by a different group of students: protocol I, toothbrushing + baseplate brushing + sterile tap water spraying once a day; protocol II, toothbrushing + baseplate brushing + Periogard spraying on the seventh day after appliance placement; and protocol III, toothbrushing + baseplate brushing + Periogard spraying on the fourth and seventh days after appliance placement. After the first week, the volunteers received new baseplates, toothbrushes, and dentifrices, and the regimens were repeated 2 more times. At the end of each week, the baseplates had a randomized disinfection protocol and were sent for microbiologic analysis. A scanning electron microscope was used to examine 3 acrylic baseplates representing each home protocol. The Friedman test (α = 0.05) compared the home protocols for the formation of MS colonies or biofilms on the acrylic surfaces.
  
  
  RESULTS
  MS colonies or biofilms were found on all acrylic baseplates after protocol I. Protocols II and III reduced significantly (P <0.05) the number of MS colonies and biofilms on the acrylic surfaces. No significant difference (P >0.05) was observed between protocols II and III. The scanning electron microscope analysis confirmed the results of the microbiologic cultures.
  
  
  CONCLUSIONS
  Disinfection of baseplates of removable orthodontic appliances by using 0.12% chlorhexidine spray once or twice a week reduced the contamination by MS on the acrylic surface in vivo.
authors: Department of Pediatric Clinics, Preventive and Community Dentistry, Ribeirão Preto Dental School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors: Iza Teixeira Alves
authors: IT
authors: Peixoto
authors: Carla
authors: C
authors: Enoki
authors: Izabel Yoko
authors: IY
authors: Ito
authors: Mirian Aiko Nakane
authors: MA
authors: Matsumoto
authors: Paulo
authors: P
authors: Nelson-Filho
mesh_terms: D000180:Acrylic Resins; D000293:Adolescent; D000328:Adult; D000891:Anti-Infective Agents, Local / Q000494:pharmacology; D018441:Biofilms / Q000187:drug effects; D002710:Chlorhexidine / Q000494:pharmacology*; D015169:Colony Count, Microbial; D018592:Cross-Over Studies; D019551:Dental Disinfectants / Q000494:pharmacology*; D004203:Disinfection / Q000379:methods*; D005260:Female; D006699:Home Care Services; D006801:Humans; D008297:Male; D008855:Microscopy, Electron, Scanning; D009968:Orthodontic Appliances, Removable / Q000382:microbiology*; D012463:Saliva / Q000382:microbiology; D018709:Statistics, Nonparametric; D013295:Streptococcus mutans / Q000187:drug effects*; D014867:Water / Q000494:pharmacology; D055815:Young Adult
chemical_list: D000180:Acrylic Resins; D000891:Anti-Infective Agents, Local; D019551:Dental Disinfectants; D014867:Water; D002710:Chlorhexidine