TABLE 1. Mean values of contraction forces (N), linear contraction (%) and wall-to-wall marginal gaps for Filtek Z250, Filtek supreme, Admira and Grandio.

Composite Resin s	Contraction forces (N) (s.d.)	Linear contraction (%) (s.d.)	Wall-to-wall marginal gap μm) (s.d.)
Filtek Z250	11.80 (0.76) a	0.516 (0.04) a	11.33 (2.16) a
Filtek Supreme	11.80 (0.71) a	0.362 (0.05) b	10.66 (1.21) a
Admira	11.89 (0.65) a	0.250 (0.04) c	11.16 (2.04) a
Grandio	12.18 (0.43) a	0.160 (0.00) d	10.50 (1.22) a

Different letters indicate statistically significant difference at 5% by Tukey's test; s.d.: standard deviation.