title: Caries-preventive effect of anti-erosive and nano-hydroxyapatite-containing toothpastes in vitro.
abstract: OBJECTIVE
  The aim of the study was to investigate the caries-preventive effect of newly developed fluoride and fluoride-free toothpastes specially designed for erosion prevention. The hypothesis was that these products might also show superior caries-inhibiting effect than regular fluoride toothpastes, since they were designed for stronger erosive acid challenges.
  
  
  METHODS
  Enamel specimens were obtained from bovine teeth and pre-demineralized (pH = 4.95/21 days) to create artificial caries lesions. Baseline mineral loss (ΔZB) and lesion depth (LDB) were determined using transversal microradiography (TMR). Ninety specimens with a median ΔZB(SD) of 6027 ± 1546 vol% × μm were selected and randomly allocated to five groups (n = 18). Treatments during pH-cycling (14 days, 4 × 60 min demineralization/day) were brushing 2×/day with AmF (1400 ppm F-, anti-caries [AC]); AmF/NaF/SnCl2/Chitosan (700 ppm F-/700 ppm F-/3500 ppm Sn2+, anti-erosion [AE1]); NaF/KNO3(1400 ppm F-, anti-erosion [AE2]); nano-hydroxyapatite-containing (0 ppm F-, [nHA]); and fluoride-free toothpastes (0 ppm F-, negative control [NC]). Toothpaste slurries were prepared with mineral salt solution (1:3 wt/wt). After pH-cycling specimens presenting lesion, surface loss (mainly by NC and nHA) were discarded. For the remaining 77 specimens, new TMR analyses (ΔZE/LDE) were performed. Changes in mineral loss (ΔΔZ = ΔZB- ΔZE) and lesion depth (ΔLD = LDB- LDE) were calculated.
  
  
  RESULTS
  All toothpastes caused significantly less demineralization (lower ΔΔZ) than NC (p < 0.05, ANOVA) except for nHA. The fluoride toothpastes did not differ significantly regarding ΔΔZ and ΔLD (p > 0.05, ANOVA).
  
  
  CONCLUSIONS
  While both anti-erosive and anti-caries toothpastes reduced mineral loss to a similar extent, the fluoride-free nano-hydroxyapatite-containing toothpaste seemed not to be suitable for inhibition of caries demineralization in vitro.
authors.affiliation: Department of Operative Dentistry, Periodontology and Preventive Dentistry, RWTH Aachen University, Pauwelsstrasse 30, 52074, Aachen, Germany. mestevesoliveira@ukaachen.de.
authors.forename: M
authors.initials: M
authors.lastname: Esteves-Oliveira
authors.affiliation: Department of Pediatric Dentistry, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.
authors.forename: N M
authors.initials: NM
authors.lastname: Santos
authors.affiliation: Department of Operative Dentistry, Periodontology and Preventive Dentistry, RWTH Aachen University, Pauwelsstrasse 30, 52074, Aachen, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Meyer-Lueckel
authors.affiliation: Department of Operative Dentistry, Periodontology and Preventive Dentistry, RWTH Aachen University, Pauwelsstrasse 30, 52074, Aachen, Germany.
authors.forename: R J
authors.initials: RJ
authors.lastname: Wierichs
authors.affiliation: Department of Pediatric Dentistry, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.
authors.forename: J A
authors.initials: JA
authors.lastname: Rodrigues
mesh_terms: D000588:Amines / Q000494:pharmacology; D000818:Animals; D002254:Carbonates / Q000494:pharmacology; D002327:Cariostatic Agents / Q000494:pharmacology*; D002417:Cattle; D048271:Chitosan / Q000494:pharmacology; D003731:Dental Caries / Q000517:prevention & control*; D017886:Durapatite / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008852:Microradiography; D053758:Nanoparticles; D009566:Nitrates / Q000494:pharmacology; D017680:Potassium Compounds / Q000494:pharmacology; D011897:Random Allocation; D012969:Sodium Fluoride / Q000494:pharmacology; D017971:Tin Compounds / Q000494:pharmacology; D014077:Tooth Erosion / Q000517:prevention & control*; D014100:Toothpastes / Q000494:pharmacology*; D017967:Zinc Compounds / Q000494:pharmacology
chemical_list: D000588:Amines; D002254:Carbonates; D002327:Cariostatic Agents; D009566:Nitrates; D017680:Potassium Compounds; D017971:Tin Compounds; D014100:Toothpastes; D017967:Zinc Compounds; C023599:stannous chloride; D012969:Sodium Fluoride; D048271:Chitosan; D017886:Durapatite; C036650:zinc carbonate; C023844:potassium nitrate
keywords: Enamel; Erosion; Fluoride; Nano-hydroxyapatite; Stannous; Toothpaste