Biomedical Engineering Reference
In-Depth Information
decreasing the friction and wear of teeth to prevent those lesions; therefore, if not
treated, people could suffer excessive tooth wear from xerostomia. The most com-
mon option for xerostomia treatment is the use of an artifi cial saliva or saliva substi-
tute (oral lubricants).
Gil et al. [
49
] reported that the accumulation of lead in teeth was associated with
dental health factors, such as dental plaque,
Lactobacillus salivarius
, dental color,
dental abrasion, and toothbrushing frequency. Colored teeth and the teeth subject to
abrasion showed the highest lead content. Teeth obtained from irregular brushers
presented higher tooth lead contents than in subjects who had a regular toothbrushing
frequency.
In addition, a clinical survey conducted by Jones et al. showed that to a lesser
extent, diffi culty with relaxation, pain and distress, and avoidance of going out are
associated with tooth loss and/or denture wearing [
50
].
3.6
Effect of Toothbrushing
As mentioned in Sect.
1.7
,
teeth are usually cleaned using a fi lament-based tooth-
brush and a toothpaste. Toothbrushes and toothpastes can be traced back 1,000
years [
51
], and toothbrushing with toothpaste is arguably the most common oral
hygiene habit in developed countries. The oral dental health benefi ts of toothbrush-
ing with toothpaste have been recognized and reviewed in a vast amount of litera-
ture: plaque removal, the control of extrinsic stains, and the delivery of preventive
and therapeutic agents for dental and gingival diseases or conditions [
52
]. A vast
amount of literature is available concerning the effect of toothbrushing on tooth
wear [
53
], and from the available information, it emerges that the toothbrush alone
appears to have no effect on enamel and very little on dentin [
51
]. Most toothpaste
also has very little effect on enamel and in normal use would not cause signifi cant
wear of dentin in a lifetime of use.
The chemical composition of a typical toothpaste is as follows [
54
]: abrasive
particles, peroxides, enzyme systems and absorbents, saccharin and peppermint fl a-
voring, and water. Toothpaste abrasive particles are made from materials such as
calcium carbonate, sodium bicarbonate, precipitated silica, pumice, and perlite,
which are used to obtain optimum stain removal during toothbrushing. Peroxides
can either dissolve or bleach the particles' stain. Enzyme systems and absorbents
are used to soften the pellicle, easing the removal process. In addition, generally
fl uorides are added to toothpastes to prevent caries and tooth erosion. Due to the
different geometries, nature, and content of abrasive particles, toothpastes can man-
ifest different abrasivities [
54
,
55
], which are normally described by the relative
dentin abrasivity value (RDA value). Although optimum stain removal is desired
from a toothpaste abrasive, it is important during the cleaning process that enamel,
dentin, or soft gum tissue is not damaged.
Various studies have been carried out to study the effects of the type of tooth-
brush and the composition, especially the abrasivity, of the toothpaste on tooth wear
