title: Erosive Effect of Different Soft Drinks on Enamel Surface in vitro: Application of Stylus Profilometry.
abstract: OBJECTIVE
  To assess the erosive potential of various soft drinks by measuring initial pH and titratable acidity (TA) and to evaluate enamel surface roughness using different exposure times.
  
  
  METHODS
  The initial pH of the soft drinks (group 1: Coca-Cola; group 2: orange juice; group 3: Cedevita; group 4: Guarana, and group 5: strawberry yoghurt) was measured using a pH meter, and TA was measured by titration with NaOH. Enamel samples (n = 96), cut from unerupted human third molars, were randomly assigned to 6 groups: experimental (groups 1-5) and control (filtered saliva). The samples were exposed to 50 ml of soft drinks for 15, 30 and 60 min, 3 times daily, during 10 days. Between immersions, the samples were kept in filtered saliva. Enamel surface roughness was measured by diamond stylus profilometer using the following roughness parameters: Ra, Rq, Rz, and Ry. Data were analyzed by one-way ANOVA, Tukey's post hoc and Student-Newman-Keuls post hoc tests.
  
  
  RESULTS
  The pH values of the soft drinks ranged from 2.52 (Guarana) to 4.21 (strawberry yoghurt). Orange juice had the highest TA, requiring 5.70 ml of NaOH to reach pH 7.0, whereas Coca-Cola required only 1.87 ml. Roughness parameters indicated that Coca-Cola had the strongest erosion potential during the 15 min of exposure, while Coca-Cola and orange juice were similar during 30- and 60-min exposures. There were no significant differences related to all exposure times between Guarana and Cedevita. Strawberry yoghurt did not erode the enamel surface regardless of the exposure time.
  
  
  CONCLUSIONS
  All of the tested soft drinks except yoghurt were erosive. Erosion of the enamel surfaces exposed to Coca-Cola, orange juice, Cedevita, and Guarana was directly proportional to the exposure time.
authors.affiliation: Department of Restorative Dentistry and Endodontics, Clinic of Dentistry, Faculty of Medicine, University of Nis, Nis, Serbia.
authors.forename: Radomir
authors.initials: R
authors.lastname: Barac
authors.forename: Jovanka
authors.initials: J
authors.lastname: Gasic
authors.forename: Natasa
authors.initials: N
authors.lastname: Trutic
authors.forename: Slavica
authors.initials: S
authors.lastname: Sunaric
authors.forename: Jelena
authors.initials: J
authors.lastname: Popovic
authors.forename: Petar
authors.initials: P
authors.lastname: Djekic
authors.forename: Goran
authors.initials: G
authors.lastname: Radenkovic
authors.forename: Aleksandar
authors.initials: A
authors.lastname: Mitic
mesh_terms: D002253:Carbonated Beverages / Q000009:adverse effects*; D003743:Dental Enamel / Q000378:metabolism*; D000067030:Fruit and Vegetable Juices / Q000009:adverse effects; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008963:Molar; D013997:Time Factors; D014097:Tooth, Unerupted; D015014:Yogurt / Q000009:adverse effects