title: The effect of ozone on progression or regression of artificial caries-like enamel lesions in vitro.
abstract: OBJECTIVE
  This study investigated the effect of ozone on the progression or regression of artificial caries-like lesions on enamel following pH cycling conditions in vitro.
  
  
  METHODS
  A randomized, single blind, four legs design was used. 20 full thickness enamel slabs were allocated to each of the four groups which were: Fluoride free toothpaste (control); ozone alone; Reductant/Patient Kit alone and a combination of both ozone/Reductant/Patient Kit. Artificial lesions were created and subjected to the pH cycling regime for a 14 days period. Assessments were carried out before and after the pH cycling on the slabs using the microhardness testing and Quantitative Light-induced Fluorescence (QLF).
  
  
  RESULTS
  Statistical significant difference were found in the percentage change of enamel microhardness before and after pH cycling between ozone/Reductant/Patient Kit group and all the other three groups of the study, as well as between Reductant/Patient Kit group and control. There was a statistical significant difference in the change of size and severity of the lesion (ΔQ) between all the three regimes tested and the control with a trend favouring ozone/Reductant/Patient Kit group.
  
  
  CONCLUSIONS
  In our model, it appeared that ozone treatment alone is not effective in protecting the enamel against demineralisation or promoting remineralisation, unless combined with the Reductant/Patient Kit, which contain high levels of fluoride.
authors.affiliation: Department of Paediatric Dentistry, Leeds Dental Institute, Leeds, UK. Electronic address: j.tahmassebi@leeds.ac.uk.
authors.forename: J F
authors.initials: JF
authors.lastname: Tahmassebi
authors.affiliation: Department of Paediatric Dentistry, Leeds Dental Institute, Leeds, UK.
authors.forename: N
authors.initials: N
authors.lastname: Chrysafi
authors.affiliation: Department of Paediatric Dentistry, Leeds Dental Institute, Leeds, UK.
authors.forename: M S
authors.initials: MS
authors.lastname: Duggal
mesh_terms: D002327:Cariostatic Agents / Q000627:therapeutic use; D003731:Dental Caries / Q000473:pathology / Q000517:prevention & control*; D003743:Dental Enamel / Q000187:drug effects* / Q000648:ultrastructure; D003804:Dentin / Q000187:drug effects / Q000648:ultrastructure; D018450:Disease Progression; D005453:Fluorescence; D005459:Fluorides / Q000627:therapeutic use; D006244:Hardness; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D015588:Observer Variation; D010083:Oxidants, Photochemical / Q000627:therapeutic use*; D010126:Ozone / Q000627:therapeutic use*; D019163:Reducing Agents / Q000627:therapeutic use; D012464:Saliva, Artificial / Q000737:chemistry; D016037:Single-Blind Method; D013696:Temperature; D014089:Tooth Remineralization / Q000379:methods
chemical_list: D002327:Cariostatic Agents; D010083:Oxidants, Photochemical; D019163:Reducing Agents; D012464:Saliva, Artificial; D010126:Ozone; D005459:Fluorides
keywords: Caries; Microhardness; Ozone