Biomedical Engineering Reference
In-Depth Information
than against the hydrothermal and machinable porcelains [
52
].
Imai
et al. studied
the wear behavior of a low-fusing/low-crystal porcelain (Finesse), a high-fusing/
low-crystal porcelain (Softspar), a heat-pressable ceramic (
IPS
E
mpress), and a
conventional porcelain (Ceramco II) [
53
]. The result revealed that the wear loss of
enamel was less when opposing the modifi ed porcelains than when opposing the
Ceramco II control. Although no statistically signifi cant differences were found
among the three modifi ed porcelains and between the conventional porcelain and
the modifi ed porcelains at every wear cycle, the high values of the Finesse after
10,000 wear cycles were probably due to its mechanical properties. Additionally, it
was reported that the exposure to a carbonated beverage signifi cantly increased the
wear loss of enamel produced by all porcelain surfaces [
52
].
In summary, normally different dental materials encounter different tribological
problems in their clinical uses. Both material properties and oral factors can signifi -
cantly infl uence the friction and wear process of restorations in the mouth. An addi-
tional aspect to be considered is the clinical operation technique. The wear resistance
of restorative materials tends to increase as the cavity size decreases. The restorations
placed should be as small as possible in order to benefi t from the strong support
of, and full protection by, the surrounding natural tooth structure [
20
,
54
,
55
].
In addition, although much improvement has been made in the mechanical proper-
ties of dental materials, the wear mechanism of dental materials and interaction
between many factors have not been fully revealed at present due to the limitation
of the subject and experimental methods.
Ideally, the wear of a dental material should be similar to that of human enamel
because enamel has an excellent wear resistance despite fairly bad working condi-
tions in the mouth, such as a wide-ranging load, reciprocating movements, temperature
shocks, or possible acid attacks. Until now, however, this ideal property may not
have been found in commonly used restorative materials, and improving current
dental materials and creating a new restorative material, one supposed to be a
biomimetic synthesis of an enamel-like material, are of extreme importance.
References
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41(11):15-16
2. Upadhyay D, Panchal MA, Dusbey RS, Srivastava VK (2006) Corrosion of alloys used in
dentistry: a review. Mater Sci Eng A 432:1-11
3. Thompson JY, Stoner BR, Piascik JR (2007) Ceramics for restorative dentistry: critical aspects
for fracture and fatigue resistance. Mater Sci Eng C 27:565-569
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26:535-576
5. Nicholson JW (2000) Adhesive dental materials and their durability. Int J Adhes Adhes
20:11-16
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(2004) Fibrous composite materials in dentistry and orthopaedics: review and applications.
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