title: Colour improvement and stability of white spot lesions following infiltration, micro-abrasion, or fluoride treatments in vitro.
abstract: OBJECTIVE
  White spot lesions (WSLs) are unwelcome side effects of fixed appliances that compromise the treatment outcome. Recently, infiltration of WSLs has been introduced as a viable treatment alternative. The objective was to evaluate the colour improvement of WSLs and their stability against discolouration following infiltration, fluoride, or micro-abrasion treatments in vitro.
  
  
  METHODS
  Artificial WSLs were created in bovine enamel (N = 96) using acidic buffer solution (pH 5, 10 days) and were randomly allocated to four groups. Specimens were treated with infiltration (Icon, DMG), fluoride (Elmex Caries Protection, GABA), and micro-abrasion (Opalustre, Ultradent) or remained untreated (control). Groups were discoloured for 24 hours in tea or tea + citric acid. Colour components and visible colour change (L*, a*, b*, ΔE) were measured spectrophotometrically on following time points: baseline, after WSL formation, after treatment, and during discolouration (8, 16, and 24 hours). Data were analysed using Kruskal-Wallis and Mann-Whitney tests.
  
  
  RESULTS
  WSL formation increased (L*) in all groups. Only infiltration reduced this effect to baseline. Highest ΔE improvement was obtained by infiltration and micro-abrasion followed by fluoride. This improvement was stable only for infiltration during discolouration. L*, a*, and b* changed significantly during discolouration in all groups except infiltration. Within the same treatment group, discolouration solutions did not differ significantly.
  
  
  CONCLUSIONS
  In vitro testing cannot replicate the actual mode of colour improvement or stability but can be used for ranking materials and techniques.
  
  
  CONCLUSIONS
  Infiltration and micro-abrasion treatments were capable of diminishing the whitish appearance of WSLs. Only infiltrated WSLs were stable following discolouration challenge.
authors.affiliation: *Department of Orthodontics, University of Ege, Izmir, Turkey, eyetkiner@hotmail.com.
authors.forename: Enver
authors.initials: E
authors.lastname: Yetkiner
authors.affiliation: **Clinic for Preventive Dentistry, Periodontology and Cariology, University of Zurich, Switzerland.
authors.forename: Florian
authors.initials: F
authors.lastname: Wegehaupt
authors.affiliation: ***Department of Preventive Dentistry, Periodontology and Cariology, University of Göttingen, Germany and.
authors.forename: Annette
authors.initials: A
authors.lastname: Wiegand
authors.affiliation: ****Clinic for Orthodontics and Pediatric Dentistry, University of Zurich, Switzerland.
authors.forename: Rengin
authors.initials: R
authors.lastname: Attin
authors.affiliation: **Clinic for Preventive Dentistry, Periodontology and Cariology, University of Zurich, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Attin
mesh_terms: D000818:Animals; D002327:Cariostatic Agents / Q000627:therapeutic use*; D002417:Cattle; D019343:Citric Acid / Q000009:adverse effects; D003116:Color; D003731:Dental Caries / Q000473:pathology / Q000628:therapy*; D003743:Dental Enamel / Q000187:drug effects / Q000473:pathology; D003959:Diamines / Q000627:therapeutic use; D019243:Enamel Microabrasion / Q000379:methods*; D005459:Fluorides / Q000627:therapeutic use*; D011092:Polyethylene Glycols / Q000627:therapeutic use; D011109:Polymethacrylic Acids / Q000627:therapeutic use; D011897:Random Allocation; D012117:Resins, Synthetic / Q000627:therapeutic use*; D013053:Spectrophotometry / Q000379:methods; D013662:Tea / Q000009:adverse effects; D014075:Tooth Discoloration / Q000209:etiology / Q000473:pathology; D014089:Tooth Remineralization / Q000379:methods
chemical_list: D002327:Cariostatic Agents; D003959:Diamines; D011109:Polymethacrylic Acids; D012117:Resins, Synthetic; D013662:Tea; C578177:icon infiltrant; C020946:triethylene glycol dimethacrylate; D019343:Citric Acid; D011092:Polyethylene Glycols; C495399:Olaflur; D005459:Fluorides