title: Characteristics of in situ oral biofilm after 2 and 4 days of evolution.
abstract: OBJECTIVE
  To analyze the evolution of the thickness, bacterial vitality, covering grade, and the structure after 2 and 4 days of aging in "non-disturbed" plaque-like biofilm (PL-biofilm).
  
  
  METHODS
  Twenty healthy volunteers wore a specific appliance. After 2 days half of the samples were removed from the appliance. Posteriorly, after bacterial vital staining, samples were analyzed using a confocal laser scanning microscope. In the first volunteer, one of the disks was analyzed using a scanning electronic microscope. The same process was realized on the remaining disks after 4 days.
  
  
  RESULTS
  The thicknesses of the PL-biofilm after 2 and 4 days were not significantly different. The bacterial vitality changed significantly from 72.50 ± 15.50% to 57.54 ± 15.66% over time, which was in contrast to the covering grade (53.08 ± 18.03% and 70.74 ± 19.11%). The structure changed from an irregular surface and compact deepest layer with a high predominance of the coccus shape to a complex structure with voids in the deepest layer and a great proportion of bacillus-shaped bacteria.
  
  
  CONCLUSIONS
  The PL-biofilm thickness remained practically constant, decreasing the bacterial vitality and increasing the covering grade over time. Regarding the structure, differences were principally bacterial disposition in the surface and bacterial shape. Clinically, the findings show that new control strategies for combating the oral biofilm should be focused on inhibiting bacterial adhesion to tooth surfaces, which would reduce biofilm formation.
authors: Isabel
authors: I
authors: Prada-López
authors: Víctor
authors: V
authors: Quintas
authors: Nikolaos
authors: N
authors: Donos
authors: David
authors: D
authors: Suárez-Quintanilla
authors: Inmaculada
authors: I
authors: Tomás
mesh_terms: D000328:Adult; D018441:Biofilms; D018592:Cross-Over Studies; D003773:Dental Plaque / Q000382:microbiology*; D004311:Double-Blind Method; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D017090:Occlusal Splints; D013997:Time Factors