Biomedical Engineering Reference
In-Depth Information
Chapter 2
Clinical Evaluation and Laboratory
Wear- Testing Methods
Being the hardest organ in body, human teeth have a very unique structure. To
understand the wear behavior of human teeth, the properties of materials and struc-
tures need to be evaluated. There are several quantitative and qualitative methods to
measure or assess these properties. This chapter reviews evaluation techniques to
understand their unique properties for both mammal and human teeth. Chapter
6
gives a more detailed discussion on artifi cial dental materials.
2.1
Clinical Evaluation Methods and Diagnosis
A number of systems for the classifi cation and measurement of tooth surface loss
have been reported in the literature.
Scott presented an ordinal dental attrition scoring technique for molar teeth
involving a quadrant system [
1
]. Molar teeth were divided into four sections and
each section scored on a 1-10 scale, as described in Table
2.1
. The sum of the four
quadrants is the score for that tooth. Such wear score categories were quickly
learned and proven useful in the analysis of dental wear data.
A few years after Scott's scoring system, Eccles developed a classifi cation
system for erosion due to nonindustrial causes; it indicates the severity and site of a
lesion on each tooth [
2
]. Three types of lesions and four kinds of surfaces were pos-
sible, as listed in Table
2.2
. Eccles believed that this may be of value in describing
the condition and as a guide to treatment.
Around the same time as Scott [
1
], a method was presented for quantitative mea-
surement based upon the samples of modern and prehistoric hunter-gatherers and
agriculturalists. An eight-stage system of occlusal wear was fully described, shown
here in Table
2.3
. Through an analysis of molar wear, Smith [
6
] believed that a
change in the wear plane angle should be an early sign of a change in diet, and that
fl atness of molar wear appeared to be a good indicator of change in food or food
preparation.
