Table 2.

Tooth Wear Index (TWI) [6]

Score	Description
	Buccal/Lingual/Occlusal	Incisal	Cervical
0	No loss of enamel surface characteristics	No loss of enamel surface characteristics	No change in contour
1	Loss of enamel surface characteristics	Loss of enamel surface characteristics	Minimal loss of contour
2	Loss of enamel exposing dentine for less than 1/3 of the surface	Loss of enamel just exposing dentine	Defect <1 mm deep
3	Loss of enamel exposing dentine for more than 1/3 of the surface	Loss of enamel and substantial loss of dentine, but not exposing pulp secondary dentine	Defect 1–2 mm deep
4	Complete loss of enamel, or pulp exposure, or exposure of secondary dentine	Pulp exposure or exposure of secondary dentine	Defect >2 mm deep, or pulp exposure or exposure of secondary dentine