Table 4. Mean volumetric wear amounts of the ceramic material groups and opposing enamel for 0 – 3 and 3 – 6 months.

Ceramic group	Material		0 - 3 months	3 - 6 months	Number of crowns
Glass matrix	Restoration	EM	0.093743	0.178314	7
		VS	0.051050	0.091275	5
					Total: 12
	Enamel	EM	0.158886	0.101757	7
		VS	0.199800	0.076300	5
					Total: 12
Resin matrix	Restoration	GC	0.317533	0.133683	7
		VE	0.249120	0.140460	5
					Total: 12
	Enamel	GC	0.127683	0.211467	7
		VE	0.235240	0.160840	5
					Total: 12
Total					24