title: The effect of fermented milk on the deciduous enamel in the presence and absence of fluoride: in vitro study.
abstract: OBJECTIVE
  This study assessed the effect of fermented milk on the enamel of primary teeth in the presence and absence of fluoride.
  
  
  METHODS
  Sixty enamel blocks (4X4 mm) underwent surface microhardness analysis (Knoop). The blocks were randomly distributed into 5 groups of 12 samples in each group according to the following treatments: Group 1) pH cycling and fermented milk (control); Group 2) pH cycling and dentifrice; Group 3) pH cycling and fermented milk and dentifrices; Group 4) varnish and pH cycling and fermented milk; Group 5) varnish and pH cycling and fermented milk and dentifrice. After the treatments, new microhardness determination was carried out and the surface microhardness change ratio was calculated (%SMH). The data were submitted to the Shapiro-Wilk normality test, ANOVA test, Tukey's test and paired t-test (P<0.05).
  
  
  RESULTS
  It was observed that after treatment, all groups showed statistically significant reduction (P<0.05) for initial surface microhardness. Group 1 showed the lowest microhardness (73.01±9.68 KNH) compared to groups 2, 3 and 4. Group 5 (172.5±45.89KNH) showed a greater surface microhardness than Group 4 (122.0±22.33 KNH).
  
  
  CONCLUSIONS
  It was concluded that the fermented milk adversely altered the microhardness of the samples and that fluorine contributes to a smaller reduction in the microhardness change ratio (SMH%). The combined solution of toothpaste with fluoride varnish provided a lower surface microhardness reduction of the samples.
authors.affiliation: Periodontics, School of Dentistry of Araraquara (Foar‑UNESP), Brazil - guioliveiraodonto@hotmail.com.
authors.forename: G J
authors.initials: GJ
authors.lastname: Pimentel Lopes De Oliveira
authors.forename: M A
authors.initials: MA
authors.lastname: Bomfim Da Silva
authors.forename: J A
authors.initials: JA
authors.lastname: Chaves De Souza
authors.forename: M
authors.initials: M
authors.lastname: Santos Alves Pereira
authors.forename: A
authors.initials: A
authors.lastname: Mendonça Cavalcante
authors.forename: J I
authors.initials: JI
authors.lastname: Limeira Dos Reis
authors.forename: L
authors.initials: L
authors.lastname: De Melo Santos
mesh_terms: D000143:Acids / Q000009:adverse effects; D000818:Animals; D002327:Cariostatic Agents / Q000008:administration & dosage / Q000494:pharmacology*; D043302:Cultured Milk Products / Q000009:adverse effects* / Q000737:chemistry; D003743:Dental Enamel / Q000187:drug effects*; D005285:Fermentation; D005460:Fluorides, Topical / Q000008:administration & dosage / Q000494:pharmacology*; D006245:Hardness Tests; D006801:Humans; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008963:Molar / Q000187:drug effects; D011897:Random Allocation; D012969:Sodium Fluoride / Q000008:administration & dosage / Q000494:pharmacology*; D014077:Tooth Erosion / Q000209:etiology / Q000517:prevention & control; D014094:Tooth, Deciduous
chemical_list: D000143:Acids; D002327:Cariostatic Agents; D005460:Fluorides, Topical; C023807:sodium fluoride topical preparation; D012969:Sodium Fluoride