Biomedical Engineering Reference
In-Depth Information
Fig. 1.7
The SEM morphologies of scratch traces on irradiated carious enamel surfaces with an
energy density of 40 J/cm
2
[
60
]
that most dentifrices used had an abrasive effect on teeth and that acidic materials
enhanced the process of toothbrushing by extracting the calcium salts from the
enamel. After then, human tooth wear and its cause in prehistoric populations was
investigated by Siffre in 1914 [
66
], and more works about the influence of various
powders and commercial dentifrices and the hardness and size of particles on tooth
wear were carried out by Head [
67
], Van Der Merve [
68
], Ray and Chaden [
69
],
Wright and Fenske [
70
], Smith [
71
], and Manly [
72
], through different mechanical
abrasion machines.
In order to control toothbrush-related abrasion, systematic studies on the
abrasive properties and dentifrices and their individual ingredients were per-
formed by Epstein and Tainter [
73
-
76
]. A mechanical brushing device was
built, and reciprocating wear tests were carried out at given experimental condi-
tions. The influence of particle size and other properties of dentifrice ingredi-
ents, as well as hydrogen concentration and hardness, on the toothbrush abrasion
of enamel were investigated. The main conclusions were that the abrasion
behavior was dependent upon both particle type and size for the sample of cal-
cium carbonate and dicalcium phosphate. The abrasion of the dentition appeared
to cause a reduction in the morphologic facial height and a smaller reduction in
the rest height [
77
].
