. 2015 Jun 9;3:e864. doi: 10.7717/peerj.864

Table 2. Arithmetical mean values of all tests (SD).

			Knoop microhardness (KHN)
Material (n = 10)	Degree of polymerization shrinkage (%)	Depth of cure (mm)	Top	Bottom	Reduction (%)
SDR	2.906 (0.04)^E	3.071 (0.05)^C	72.725 (1.24)^D	64.810 (0.04)^G	10.37
TNF	4.217 (0.08)^G	2.893 (0.07)^B	55.599 (0.02)^B	41.858 (0.55)^A	24.64
FZ350F	4.112 (0.05)^F	2.837 (0.13)^B	53.712 (1.32)^A	45.124 (0.16)^B	14.09
EXHD	2.256 (0.09)^D	2.612 (0.10)^A	77.422 (1.25)^F	61.321 (0.53)^D	21.01
TNC	2.031 (0.13)^B	2.544 (0.23)^A	64.130 (1.15)^C	52.029 (0.44)^C	18.62
FZ350	2.134 (0.07)^C	2.567 (0.13)^A	78.664 (0.68)^G	63.282 (0.81)^F	19.89
FP90	1.015 (0.12)^A	2.679 (0.06)^A	73.704 (0.61)^E	62.620 (0.69)^E	14.98

Notes.

Values in each column represent the means and standard deviation (in parentheses). Upper-case letters in superscript designate groups whose p values for a given parameter (polymerization shrinkage, depth of cure or KHN) were not statistically different (p > 0.05).