Topographic
and micromechanical features of TRC and titanium surfaces.
Secondary electron images under SEM and corresponding vertex extraction
images and Voronoi diagrams of (a, f, and k) machined (MA), (b, g,
and l) microroughened (MR), (c, h, and m) nanoroughened (NR), and
(d, i, and n) TRC-mimetic (CM) titanium surfaces and (e, j, and o)
TRC, respectively. (p) Anisotropy and (q) randomness in the vertex
distribution on titanium and TRC surfaces were measured by analyzing
vertex extraction images and Voronoi diagrams. (r) Bird’s-eye
view of 3D reconstruction images (panels) and vertical roughness parameters
(histograms) on titanium and TRC surfaces by 3D SEM. Three independent
regions on one sample. Data are presented as the mean ± SD with
dot plots. Different letters indicate statistically significant differences
between them (p < 0.05; Tukey’s HSD test).
(s) Microhardness and (t) microelastic modulus measured by nanoindentation
on NR and CM titanium surfaces and TRC surfaces. Seven to ten independent
spots on one surface. Data are presented as box and dot plots with
a mean point. *Statistically significant differences among NR and
CM titanium and TRC surfaces (p < 0.05; Tukey’s
HSD test) (s). n.s. indicates no statistically significant
differences between TRC and CM titanium surfaces (p > 0.05; Tukey’s HSD test) (s) or among TRC and NR and
CM
titanium surfaces (p > 0.05; Tukey’s HSD
test)
(t). (u) Multidimensional plots (left) of the horizontal pattern of
vertex distribution, vertical roughness, and micromechanical properties
of TRC1–TRC3 and titanium disks with an MA, MR, NR, or CM surface.
The Euclidean distance (right) between TRC1 and others measured by k nearest neighbor analysis on multidimensional plots. TRC,
tooth root cementum; SEM, scanning electron microscopy; HSD, honestly
significant difference; SD, standard deviation.