What treatment does each stage of tooth wear need?

What the drawing is measured from

1. The grades: the Tooth Wear Evaluation System 2.0 grades the biting surface of a tooth by wear within the enamel, dentine exposed with up to a third of the crown's height lost, a third to two thirds lost, and two thirds or more. It also lists the signs of mechanical and chemical wear. No grading scale has been validated against measured tissue loss on a single tooth, so these drawings illustrate grades and do not measure them. DOI 1
2. European consensus on severe tooth wear: wear is severe once at least a third of the clinical crown has been lost; with no complaints, patients are monitored first; preparation is limited to what is necessary, such as seats, bevels or chamfers; and restorations change the rate, location and nature of wear rather than prevent it. DOI 2
3. Direct composite for severe wear: 34 patients and 1,269 restorations followed for a mean of 62.4 months, with annual failure rates of at most 2.2% in front teeth and 2.9% in back teeth; molars needed the most maintenance. DOI 3
4. The pulp: wear is usually slow and pulp death is rare, yet 11.6% of 448 patients referred for excessive wear had near or frank exposures or root canal treatment. No study gives, in millimetres, how far the human pulp draws back under wear, so the distance drawn is representative. DOI 4
5. Woelfel's Dental Anatomy: wear facets on the incisal edges of upper incisors slope cervically toward the palate. No study gives a facet angle, so none is printed here.
6. The teeth are the measured upper central incisor and lower first molar used in every figure on this site. How deep each worn surface, hollow and notch is drawn is representative, not a measurement of one patient.