title: Viability of Streptococcus mutans on transparent and opaque toothbrushes.
abstract: OBJECTIVE
  The objective of this study was to evaluate the viability of the microorganism Streptococcus mutans on toothbrushes made of opaque and transparent materials.
  
  
  METHODS
  Twenty-eight toothbrushes (14 opaque and 14 transparent) were inoculated in tubes with brain heart infusion (BHI) broth of a standard strain of S. mutans and incubated in candle jars at 37 degrees C for 24 hours. Both the opaque and transparent toothbrushes were removed at T = 0 h (control); T = 0.5 h; T = 1 h; T = 2 h; T = 4 h; T = 8 h; and T = 24 h. Individual toothbrushes were subjected to agitation in a saline solution and samples of the solution were diluted and inoculated in Bacitracin Sucrose Agar--SB-20.
  
  
  RESULTS
  After half an hour (T2) there was a significant decrease in the number of microorganisms on the transparent and opaque toothbrushes, respectively 6.0 x 10(5) and 9.4 x 10(5), when compared to the control. After the T3 = 1 hour, T4 = 2 hours, T5 = 4 h, the number of microorganisms decreased from 4.1 x 10(5); 2.1 x 10(5); 1.4 x 10(5); and 9.2 x 10(5); 5.7 x 10(5); 1.2 x 10(5) to zero (0.0) in T6 = 8 h, respectively on the transparent and opaque toothbrushes. The reduction in viable microorganisms was more obvious with the transparent toothbrushes, although the number of viable microorganisms was not significantly different for the two types of toothbrushes at the end of the experiment, T5 = 1.4 x 10(5) (transparent) and T5 = 1.2 x 10(5) (opaque).
  
  
  CONCLUSIONS
  With both opaque and transparent toothbrushes, the number of microorganisms decreased with time. A reduction in the number of microorganisms on the transparent toothbrushes was observed following inoculation and incubation. This suggests the transparent toothbrushes inhibit the viability of the S. mutans.
authors.affiliation: Department of Physiology and Pathology, Araraquara Dental School, São Paulo State University, UNESP, Araraquara, SP, Brazil.
authors.forename: Denise M Palomari
authors.initials: DM
authors.lastname: Spolidorio
authors.forename: Emy
authors.initials: E
authors.lastname: Goto
authors.forename: Thaís de Cássia
authors.initials: Tde C
authors.lastname: Negrini
authors.forename: Luís Carlos
authors.initials: LC
authors.lastname: Spolidorio
mesh_terms: D015169:Colony Count, Microbial; D003742:Dental Devices, Home Care / Q000382:microbiology*; D008027:Light; D009757:Nylons; D010969:Plastics; D013295:Streptococcus mutans / Q000254:growth & development*; D014099:Toothbrushing / Q000295:instrumentation*
chemical_list: D009757:Nylons; D010969:Plastics