Table 3. Comparison of gloss by resin composite and polishing system. Before and after the aging process.

X±SD: mean±standard deviation; a p-value < 0.05 indicates statistically significant differences, based on the paired t-Student test; GU: gloss units; BA: before aging; AA: after aging.

Resin Treatment		Spectra (GU)	Tetric (GU)	Z250 XT (GU)	Zafira (GU)
		X±SD	X±SD	X±SD	X±SD
Control	BA	71.8 ± 15.5	70.0 ± 8.4	61.8 ± 10.3	66.6 ± 11.0
	AA	75.4 ± 9.7	67.0 ± 6.3	66.7 ± 13.4	70.4 ± 13.2
	p-value	0.192	0.057	0.076	0.043
Clinical polishing	BA	33.5 ± 5.7	39.5 ± 5.0	77.2 ± 3.4	43.8 ± 12.3
	AA	25.6 ± 6.5	49.0 ± 8.5	76.2 ± 9.4	34.8 ± 9.5
	p-value	0.247	0.045	0.893	0.093
Metallographic polishing	BA	87,4 ± 1,7	75.7 ± 11,1	78.3 ± 1.6	92.7 ± 3.8
	AA	84.3 ± 2.2	76.1 ± 8.8	79.0 ± 2.3	90.7 ± 4.3
	p-value	0.068	0.849	0.218	0.139
Clinical polishing + PermaSeal	BA	45.3 ± 11.9	43.9 ± 9.3	53.6 ± 14.0	55.5 ± 7.1
	AA	42.9 ± 10.2	47.9 ± 9.8	53.5 ± 3.8	57.2 ± 18.4
	p-value	0.786	0.316	0.986	0.887
Glycerin + clinical polishing	BA	42.7 ± 10.0	74.7 ± 9.3	78.9 ± 20.4	52.5 ± 14.2
	AA	38.5 ± 3.9	56.6 ± 12.2	78.6 ± 11.4	54.8 ± 14.3
	p-value	0.652	0.071	0.953	0.760