Table 4: Averages and standard deviations of the initial and final values for Knoop microhardness (KHN) and percentages of microhardness.

Groups
(n= 5)
Initial KHN
Average and standard deviation
Final KHN
Average and standard deviation
%KHN
OP38 344.6 ± 7.63 Aa* 360.1 ± 26.18 Aa* 4.40%
PO37 347.2 ± 13.07 Aa* 356.8 ± 17.1 Aa* 2.70%

*Groups with the same letters are statistically similar (uppercase letters in columns and lowercase letters in rows).