Page 269 - IJB-10-5

International Journal of Bioprinting A TPMS framework for complete dentures

 cx,y,z) =−0.064 ⋅ x + y + 0.9 Table 2. Expression of gradient porous-structure function
(
2
2
 (X) Function

(
2
30.143
 tx,y,z) =− ⋅ x + y 2 Type c(x,y,z) t(x,y,z)

The derivation methods for c(x,y,z) and t(x,y,z) A-I –0.064 . x + y + 0.9 3 – 0.143 . x + y 2
2
2
2
of the other eight structures are analogous, and their
corresponding outcomes are presented in Table 2. A-II –0.064 . x + y + 0.9 2 + 0.143 . x + y 2
2
2
2
Substituting the expressions c(x,y,z) and t(x,y,z) for each
2
2
structure into Equation VII yields the model expression. A-III –0.064 . x + y + 0.9 2.5
Nine gradient porous models were modeled in B-I 0.064 . x + y + 0.45 3 – 0.143 . x + y 2
2
2
2
MSLattice (Oraib Al-Ketan, UAE). This software offers
39
flexibility, enabling users to design their own TPMS lattice B-II 0.064 . x + y + 0.45 2 + 0.143 . x + y 2
2
2
2
based on level-set approximations. The modeling principle
involves offsetting the level-set approximation equation B-III 0.064 . x + y + 0.45 2.5
2
2
used to define the isosurface, followed by constructing
a solid domain at spatial nodes enclosed between two C-I 0.68 3 – 0.143 . x + y 2
2
surfaces to obtain the lattice structure. The schematic
diagrams of the resulting nine gradient change models C-II 0.68 2 + 0.143 . x + y 2
2
are illustrated in Figure 4. Additionally, it can be observed
from the figure that the transitions between gradients are C-III 0.68 2.5
uniform and consistent with the design.
outlined in Section 2.1.2., optimal gradient structures
2.1.3. Framework design of implant-supported fixed suitable for the required sizes were generated. The
complete dentures based on the optimal gradient structural type remained consistent, with the same gradient
TPMS structure variations in unit size and relative density. Using the center
The mechanical properties of TPMS structures change
with a radial gradient, unlike uniform structures. Firstly, point of each tooth as the gradient center, these structures
the gradient TPMS structure with the best mechanical were then filled into IFCDs to create functional gradient
properties was identified through experiments and FEA. TPMS frameworks. Figure 5A illustrates the filling process
Subsequently, based on the dimensions of each tooth in for molars, with the remaining teeth filled sequentially
IFCDs and the TPMS gradient structure design method using the same approach.

Figure 4. The overall schematic and top views of the three-periodic minimal surface (TPMS)-based gradient porous models.

Volume 10 Issue 5 (2024) 261 doi: 10.36922/ijb.3453