Skewness and Kurtosis: Important Parameters in the Characterization of Dental Implant Surface Roughness—A Computer Simulation

Table 1

2D surface roughness parameters dealt with in the present study.

Parameter name	Symbol	Digital implementation of mathematical formula	Type	Description
Average roughness	𝑅𝑎	1𝑚^𝑚𝑖∑=1|𝑧(𝑥𝑖)|	Height	Average absolute deviation from profile mean line
Root-mean-square roughness	𝑅𝑞	1𝑚^𝑚𝑖∑=1𝑧^2(𝑥𝑖)	Height	Root-mean-square deviation from profile mean line
Skewness	𝑅sk	1𝑚^𝑚𝑖∑=1𝑧^3(𝑥𝑖)𝑅^3𝑞	Height	Third central moment of profile amplitude probability density function
Kurtosis	𝑅ku	1𝑚^𝑚𝑖∑=1𝑧^4(𝑥𝑖)𝑅^4𝑞	Height	Fourth central moment of profile amplitude probability density function
Mean width of profile elements	𝑅𝑆𝑚		Space	Mean separation of excursions above profile mean line
Developed length ratio	𝑅dr	1𝑥𝑚−𝑥1𝑚−1𝑖∑=1(𝑧𝑖+1−𝑧𝑖)^2+(𝑥𝑖+1−𝑥𝑖)^2	Hybrid	The relationship between stretched length and scanned length