Table.

Micromechanical Characteristics of Murine Enamel from 4 Compositional Groups^* Used in the Study (Values represent x̄ ± SD) and Their Statistical Comparison (t test, α = 0.05)

						p values
		Wet Untreated	Dry Untreated	Dry Treated	Wet Treated	Wet Untreated vs. Wet Treated	Dry Untreated vs. Dry Treated	Wet Untreated vs. Dry Untreated	Wet Treated vs. Dry Treated
Hardness (HV0.981)	Mid-saggital plane	301 ± 8	345 ± 4	364 ± 8	369 ± 12	< 0.001	< 0.001	< 0.001	0.09
	Transverse plane	319 ± 5	325 ± 11	336 ± 5	341 ± 11	< 0.001	< 0.001	0.02	0.06
Fracture toughness (MPa*m1/2)	Mid-saggital plane	1.57 ± 0.1	1.22 ± 0.1	1.01 ± 0.1	0.91 ± 0.13	< 0.001	< 0.001	< 0.001	0.04
	Transverse plane	0.57 ± 0.1	0.52 ± 0.1	0.33 ± 0.06	0.31 ± 0.06	< 0.001	< 0.001	0.13	0.23
Crack length (μm)	Mid-saggital plane	13.8 ± 0.9	15.7 ± 0.9	17.4 ± 1.1	18.7 ± 1.9
	Transverse plane	27.1 ± 3.5	28.8 ± 4.4	38.4 ± 5.5	40.2 ± 5.1

^*Three samples per group were tested; from 10 to 14 micro-indentations in the mid-sagittal plane and from 5 to 9 in the transverse plane were performed on each sample.