Clinical Evaluation and Laboratory Wear- Testing Methods - Dental Biotribology - page 34

Table 2.4 Ordinal scale used for grading severity of occlusal wear
Score Diagnostic criteria
0 No visible facets in the enamel. Occlusal/incisal morphology intact
1 Marked wear facets in the enamel. Occlusal/incisal morphology altered
2 Wear into the dentin. The dentin exposed occlusally/incisally or adjacent tooth surface.
Occlusal/incisal morphology changed in shape, with height reduction of the crown
3 Extensive wear into the dentin, large dentinal area (>2 mm 2 ) exposed occlusally/
incisally or adjacent tooth surface. Occlusal/incisal morphology totally lost locally
or generally. Substantial loss of crown height
4 Wear into secondary dentin (verifi ed by photographs)
Source : From Johansson et al. [ 4 ]

Table 2 .5 Scale used for scoring progression of occlusal wear
Score Diagnostic criteria
0 No defi nite change in previously recorded area(s)
1 Visible change, such as an increase of the facets area(s), without any measurable
reduction of crown length; occlusal/incisal morphology changed in shape compared
to the fi rst examination
2 Measurable reduction of crown length, <1 mm
3 Marked reduction of crown length, >1 mm
Source : From Johansson et al. [ 4 ]

Table 2.6 Diagnostic criteria for tooth wear index. B buccal or labial, L lingual or palatal,
O occlu sal, I incisal
Score Diagnostic criteria Surfaces

0 No loss of enamel surface characteristics B, L, O, I

1 Loss of enamel surface characteristics B, L, O, I

2 Loss of enamel, visible dentin on less than one third of the surface area B, L, O

Loss of enamel with visible dentin I

3 Loss of enamel, visible dentin on more than one third of the surface area B, L, O

Loss of enamel and substantial loss of dentin but not exposing pulp or
secondary dentin

I

4 Complete loss of enamel, pulp exposure, or exposure of secondary dentin B, L, O

Pulp exposure, or exposure of secondary dentin I

Source : From Millward et al. [ 5 ]

2.2 Wear Modes and Location

2.2.1 Wear Modes

Friction and wear can result from direct contact between teeth and from any abrasive
particles or devices sandwiched between them during mastication, thegosis, bruxism,
toothbrushing, and other functions. Tooth surface loss caused by wear is a common