title: Impact of toothpaste on abrasion of sound and eroded enamel: An in vitro white light interferometer study.
abstract: OBJECTIVE
  To evaluate the influence of brushing using toothpastes marketed under different categories on abrasion of sound and eroded enamel in vitro at nanometer scale using a white light interferometer (WLI).
  
  
  METHODS
  Enamel surface of resin-embedded bovine incisors were fine polished with diamond slurry and divided into testing area (approximately 2 mm x 4 mm) and reference area using a nail varnish. The enamel specimens were randomly assigned to 10 groups (n = 10 each); six of which were subjected to erosive challenge. The testing area in these eroded groups was exposed to 10 ml of Coca-Cola for 90 seconds and then rinsed for 10 seconds in deionized water (DW). Enamel specimens, except for those in one eroded group, were brushed by an automatic brushing machine with 120 linear motion strokes in 60 seconds under load of 250 g with/without toothpaste slurry. After the toothbrushing abrasion, each specimen was rinsed for 10 seconds with DW followed by immersion in artificial saliva for 2 hours. Toothpaste slurries were prepared containing one of the four toothpastes used and DW in a ratio of 1:2. The erosion-abrasion cycle was repeated three times. Then, the nail varnish was removed and enamel surface loss (SL) was measured by the WLI. Data were statistically analyzed by one-way ANOVA followed by Bonferroni's correction at significance level of 0.05.
  
  
  RESULTS
  For eroded specimens, the mean SL values of groups not brushed and brushed with no toothpaste were not significantly different, but were significantly lower than those of whitening, anti-erosion and anti-caries toothpaste groups (P < 0.001). The whitening toothpaste group showed significantly higher SL than all other groups (P < 0.001). For sound enamel specimens, SL was not measured except for the whitening toothpaste group.
authors.forename: Maria
authors.initials: M
authors.lastname: Nakamura
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Kitasako
authors.forename: Syozi
authors.initials: S
authors.lastname: Nakashima
authors.forename: Alireza
authors.initials: A
authors.lastname: Sadr
authors.forename: Junji
authors.initials: J
authors.lastname: Tagami
mesh_terms: D000143:Acids; D000818:Animals; D002253:Carbonated Beverages / Q000009:adverse effects; D002327:Cariostatic Agents / Q000009:adverse effects; D002417:Cattle; D003743:Dental Enamel / Q000648:ultrastructure*; D006863:Hydrogen-Ion Concentration; D008027:Light; D008857:Microscopy, Interference / Q000295:instrumentation; D011897:Random Allocation; D012464:Saliva, Artificial / Q000737:chemistry; D013997:Time Factors; D014072:Tooth Abrasion / Q000209:etiology*; D058205:Tooth Bleaching Agents / Q000009:adverse effects; D014077:Tooth Erosion / Q000209:etiology / Q000473:pathology*; D014099:Toothbrushing / Q000009:adverse effects; D014100:Toothpastes / Q000009:adverse effects* / Q000145:classification
chemical_list: D000143:Acids; D002327:Cariostatic Agents; D012464:Saliva, Artificial; D058205:Tooth Bleaching Agents; D014100:Toothpastes