Table 3.

Smith and Knight Tooth Wear Index [48]

Score	Surface	Criterion
0	B/L/O/I/C	No loss of surface characteristic, no loss of contour
1	B/L/O/I/C	Loss of enamel surface characteristics, minimal loss of contour
2	B/L/O	Loss of enamel exposing dentine for less than one third of the surface
	I	Loss of enamel just exposing dentine
	C	Defect less then 1 mm deep
3	B/L/O	Loss of enamel exposing dentine for more than one third of surface
	I	Loss of enamel and substantial loss of dentine not exposing secondary dentine or pulp
	C	Defect 1–2 mm deep
4	B/L/O	Complete loss of enamel, or pulp exposure, or exposure of secondary dentine
	I	Pulp exposure or exposure of secondary dentine
	C	Defect more than 2 mm deep, or pulp exposure, or exposure of secondary dentine

B Buccal or labial, L lingual or palatal, O occlusal, I incisal, C cervical