Table 1.

Comparison of amount of natural enamel wear against polished yttrium tetragonal zirconia Crowns (Group 1) with enamel wear against natural antagonist (Control Group)

Case number	Group 1 – Polished yttrium–tetragonal polycrystals crowns			Control group
	Tooth number with crowns	Antagonist tooth number	Enamel wear (mm) against crowns	Natural teeth considered	Mean enamel wear (mM) of natural antagonist
1	16	46	52.34	26.36	34.25
2	46	16	32.35	26.36	35.24
3	26	36	35.12	16.46	32.14
4	26	36	40.00	16.46	30.90
5	36	26	40.12	16.46	43.05
6	26	36	48.97	16.46	27.75
7	26	36	40.17	16.46	32.03
8	37	27	42.35	17.47	30.03
9	46	16	38.46	26.36	32.17
10	26	36	34.82	16.46	34.55
11	16	46	54.24	26.36	32.32
12	17	47	46.04	27.37	42.18
13	36	26	42.03	16.46	41.65
14	46	16	35.02	26.36	35.05
15	46	16	48.00	26.36	37.01