title: High frequency ultrasound imaging of a single-species biofilm.
abstract: OBJECTIVE
  This study evaluated the feasibility of a high frequency ultrasound scan to examine the 3D morphology of Streptococcus mutans biofilms grown in vitro.
  
  
  METHODS
  Six 2-day S. mutans biofilms and six 7-day biofilms were grown on tissue culture membranes and on bovine dentine discs. A sterile growth medium on the membrane and disc were used as controls. Surfaces were rinsed and then immersed in sterile saline. High-frequency ultrasound imaging system was used to scan these surfaces at 55MHz, and a computer program calculated the average thickness of the biofilm layer from the 3D images.
  
  
  RESULTS
  3D pictures of the biofilm layers were obtained. Different cross-sections and plains are easily demonstrated. The average thickness of the 7-day biofilm was significantly bigger than the 2-day on both the membranes and dentinal discs. No structures were observed on the sterile membrane or disc.
  
  
  CONCLUSIONS
  Three-dimensional structural imaging in situ is possible without damaging the biofilm layer in a quick and easy manner and can therefore be used to evaluate biofilms longitudinally as a function of time.
authors.affiliation: Department of Cariology Endodontology Pedodontology, Academic Centre for Dentistry Amsterdam (ACTA), Louwesweg 1, 1066 EA Amsterdam, The Netherlands. hshemesh@acta.nl
authors.forename: H
authors.initials: H
authors.lastname: Shemesh
authors.forename: D E
authors.initials: DE
authors.lastname: Goertz
authors.forename: L W M
authors.initials: LW
authors.lastname: van der Sluis
authors.forename: N
authors.initials: N
authors.lastname: de Jong
authors.forename: M K
authors.initials: MK
authors.lastname: Wu
authors.forename: P R
authors.initials: PR
authors.lastname: Wesselink
mesh_terms: D000818:Animals; D018441:Biofilms / Q000254:growth & development*; D002417:Cattle; D003804:Dentin / Q000000981:diagnostic imaging / Q000382:microbiology*; D005240:Feasibility Studies; D013295:Streptococcus mutans / Q000502:physiology*; D013997:Time Factors; D014463:Ultrasonography / Q000379:methods