2026 Volume 39 Issue 2 Pages 107-113
Purpose: To evaluate the use of rigid polyurethane bone-simulating blocks with densities of 40 pcf, 30 pcf, and 20 pcf for implant site preparation training, this study compared the internal structure, mechanical strength, and cutting torque values of these blocks with those of oak, white pine, and balsa wood ─ materials that Misch used to simulate the sensation of bone drilling.
Methods: The internal structures of the various simulated bone blocks and wood samples were observed using a scanning electron microscope (SEM), and Vickers hardness and three-point bending strength were measured. Cutting torque values during implant site preparation were also measured using pilot and final drills, and statistical analysis was performed using one-way analysis of variance (ANOVA) and the Kruskal–Wallis test (α＝0.05).
Results: SEM observations revealed that the various simulated bone materials consisted of spherical voids ranging from 100 to 400 μm in size, with differences in their number and distribution. Similarly, differences were observed in the shape, proportion, and distribution of voids in the wood samples. The mean Vickers hardness (Hv) values for the various samples (40 pcf, 30 pcf, 20 pcf, oak, white pine, and balsa) were 43.7, 22.8, 15.3, 22.0, 14.5, and unmeasurable, respectively, while the mean values for three-point bending strength (MPa) were 25.7, 15.4, 6.3, 82.5, 83.2, and 25.2. The average cutting torque values (N・cm) for the pilot drill were 5.25, 2.08, 1.43, 7.22, 3.32, and 1.24, and for the final drill were 11.35, 7.28, 2.53, 27.2, 13.8, and 2.6.
Conclusion: The results of significance tests comparing Vickers hardness, three-point bending strength, and cutting torque values among various simulated bone blocks and Misch-classified woods showed that, in terms of Vickers hardness, the 20 pcf simulated bone was equivalent to white pine, while the 30 pcf and 40 pcf samples were equivalent to oak. In terms of threepoint bending strength, the 40 pcf sample was equivalent to balsa wood. Regarding cutting torque values, for both pilot and final drills, the 20 pcf block was equivalent to balsa wood, while the 40 pcf block was equivalent to white pine and oak.
