title: The importance of measuring toothpaste abrasivity in both a quantitative and qualitative way.
abstract: OBJECTIVE
  To evaluate the relative abrasivity of different toothpastes and polishing pastes both qualitatively and quantitatively.
  
  
  METHODS
  Acrylic plates were exposed to brushing in a brushing machine with a toothpaste/water slurry for 1 and 6 h. Twelve different toothpastes were used and also four different polishing pastes. The results were evaluated using a profilometer after 1 and 6 h of brushing (corresponding to 2000 and 12 000 double strokes, respectively). A surface roughness value (Ra-value) and also a volume loss value were calculated from the profilometer measurements. These values were then correlated to each other. An unpaired t-test for the difference in the abrasion values between the toothpastes and the abrasion values over time was used.
  
  
  RESULTS
  The polishing paste RDA® 170 yielded higher Ra-values than RDA 250®, both after 1 and 6 h of brushing (1.01 ± 0.22 and 8.99 ± 1.55 compared to 0.63 ± 0.26 and 7.83 ± 5.89, respectively) as well as volume loss values (3.71 ± 0.17 and 20.20 ± 2.41 compared to 2.15 ± 1.41 and 14.79 ± 11.76, respectively), thus poor correlations between the RDA and Ra and Volume loss values were shown. Among the toothpastes, Apotekets® showed the highest Ra value after 1 h of brushing and Pepsodent® whitening after 6 h of brushing. Pepsodent® whitening also showed the highest volume loss values, both after 1 and 6 h of brushing.
  
  
  CONCLUSIONS
  This study emphasizes the importance of not only considering the RDA value, but also a roughness value, when describing the abrasivity of a toothpaste. Furthermore, it can be concluded that so called 'whitening' toothpastes do not necessarily have a higher abrasive effect than other toothpastes.
authors: Department of Periodontology, Danakliniken, Danderyd, Sweden. gunnar.johannsen@danakliniken.se
authors: Gunnar
authors: G
authors: Johannsen
authors: Georg
authors: G
authors: Tellefsen
authors: Annsofi
authors: A
authors: Johannsen
authors: Anders
authors: A
authors: Liljeborg
mesh_terms: D003775:Dental Polishing; D008422:Materials Testing; D014072:Tooth Abrasion; D014100:Toothpastes
chemical_list: D014100:Toothpastes