Objectives: The objective of this work was to illustrate the sensitivity and robustness of the microabrasion test. This was achieved by testing eight commercial toothpastes in one study and testing high, medium and low abrasive toothpaste over six replicates.
Methods: Bovine enamel specimens were prepared to 3µm diamond finish, clamped in the test equipment, a 0.04N load applied, drop wise addition of toothpaste slurry (25g paste to 40ml DI water) applied to the sample-ball contact, before the ball was driven for 1200revolutions. The crater diameters (CD) were measured using a light microscope. The first experiment measured the enamel abrasivity of 8 commercial toothpastes and the CD was analysed using ANOVA. The second experiment measured the enamel abrasivity of three toothpastes over six replicates, the results were analysed using ANOVA.
Results: The toothpaste abrasives being employed can be placed in the following order according to the size of their CD; dicalcium phosphate<
Conclusions: Micro-abrasion has been shown to differentiate between commercial toothpastes that use different abrasive systems and has produced very similar CD’s for the same toothpastes when tested in different studies. One can conclude that the micro-abrasion test is a sensitive and robust test method that can be performed in a normal laboratory environment.
Sample
|
CD,mm (SEM,n=10)
|
Crest Whitening Expressions
|
0.87b(0.08)
|
Crest Cavity Protection(CrCP)
|
0.72c(0.02)
|
Colgate Max White
|
0.71c(0.05)
|
Colgate Cavity Protection(CoCP)
|
0.45d(0.03)
|
Arm &Hammer Advanced Whitening
|
0.66c(0.05)
|
Pearl Drops Daily Shine(PDDS)
|
1.14a(0.03)
|
Signal White Now
|
0.59cd(0.03)
|
Aquafresh Multiaction Whitening
|
0.98b(0.0510)
|
Table1 CD for 8 toothpaste slurries.
Study No
|
CD,mm(SEM,n=6)
|
CoCPc
|
CrCPb
|
PDDSa
|
1
|
0.44(0.04)c 0.56(0.05)b 0.43(0.03)c 0.48(0.03)c 0.53(0.05)c 0.42(0.04)c
|
0.71(0.05)b 0.67(0.04)b 0.65(0.02)b 0.62(0.01)b 0.64(0.03)b 0.65(0.05)b
|
1.17(0.06)a 1.23(0.02)a 1.13(0.04)a 1.17(0.01)a 1.08(0.04)a 1.09(0.02)a
|
2
|
3
|
4
|
5
|
6
|
OverallCV
|
|
23.2%
|
|
13.53%
|
|
9.23%
|
|
|
|
|
|
|
|
Table 2 CD for 3 toothpaste slurries over 6 studies.
*Same letter denotes no significant difference between toothpastes for both tables.