In Situ Tooth Replica Custom Implant: A 3-Dimensional Finite Element Stress and Strain Analysis
This study is a phase of a biomechanical study, a part of a research program concerned with the new concept of in situ tooth replication. The purpose of the study was to evaluate tooth replica under each of two possible circumstances: (1) attachment via periodontal ligament and (2) osseointegration. Replicas were made of Cortoss, a bioactive glass, bone substitute. Three-dimensional finite element analysis was used to assess the stresses and strains resulting from each of 2 types of loads: off-vertical pressure and vertical point force acting on natural mandibular second premolar and corresponding replicas. Natural tooth tolerated 19 MPa pressure or 85 N vertical force, periodontally attached replica tolerated 15 MPa pressure or 80 N force, and osseointegrated replica tolerated 23 MPa pressure or 217 N force.
Figure 1. Three-dimensional finite element models. (a) Outer view of full model. (b) Close-up view of the models with periodontal ligament, in translucent style. (c) Tooth stump and its periodontal ligament. (d) Close-up view of the model with osseointegration, in translucent style. (e) Tooth stump without periodontal ligament. Figure 2. Constraints and loads. Displacement constraints are indicated by triangles. Shown is the mesial surface. Left, pressure (white net) applied on the distobuccal aspect of the buccal cusp. Right, vertical force (red arrow) applied—apical ward—on the cusp tip of the buccal cusp.
Figure 3. Von Mises stress (SEQV) generated in cancellous bone surrounding natural tooth as a result of 19 MPa masticatory pressure; full view (left) and close-up view showing inside the socket (right). Unit is Pa. Figure 4. Von Mises total mechanical strain (EPTOEQV) generated in cancellous bone surrounding natural tooth as a result of 19 MPa masticatory pressure; full view (left) and close-up view showing inside the socket (right). Unit is strain. One strain = 106 micro strain. Figure 5. Von Mises stress (SEQV) generated in cortical bone surrounding natural tooth as a result of 19 MPa masticatory pressure; full view (left) and close-up view showing the crestal bone (right). Unit is Pa. Figure 6. Strains generated in cortical bone surrounding natural tooth as a result of 19 MPa masticatory pressure; full view (left) and close-up view showing the crestal bone (right). Unit is strain. One strain = 106 micro strain. Figure 7. Von Mises stress (SEQV) generated in body of natural tooth as a result of 19 MPa masticatory pressure. (a) Mesial and apical aspect with close-up view of region of maximum stress at the apex. (b) Lingual aspect. (c) Distal and occlusal aspect. (d) Buccal aspect. Unit is Pa.
Figure 18. Von Mises stress (SEQV) generated in cancellous bone surrounding natural tooth as a result of 85 N masticatory force; full view (left) and close-up view showing inside the socket (right). Unit is Pa. Figure 19. Strains generated in cancellous bone surrounding natural tooth as a result of 85 N masticatory force; full view (left) and close-up view showing inside the socket (right). Unit is strain. One strain = 106 micro strain. Figure 20. Von Mises stress (SEQV) generated in cortical bone surrounding natural tooth as a result of 85 N masticatory force; full view (left) and close-up view showing the crestal bone (right). Unit is Pa. Figure 21. Strains generated in cortical bone surrounding natural tooth as a result of 85 N masticatory force; full view (left) and close-up view showing the crestal bone (right). Unit is strain. One strain = 106 micro strain. Figure 22. Von Mises stress (SEQV) generated in body of natural tooth as a result of 85 N masticatory force. (a) Mesial and apical aspect with close-up view of region of maximum stress at the apex. (b) Lingual aspect. (c) Distal and occlusal aspect. (d) Buccal aspect. Unit is Pa.
Figure 8. Von Mises stress (SEQV) generated in cancellous bone surrounding periodontally attached replica as a result of 15 MPa masticatory pressure; full view (left) and close-up view showing inside the socket (right). Unit is Pa. Figure 9. Strains generated in cancellous bone surrounding periodontally attached replica as a result of 15 MPa masticatory pressure; full view (left) and close-up view showing inside the socket (right). Unit is strain. One strain = 106 micro strain. Figure 10. Von Mises stress (SEQV) generated in cortical bone surrounding periodontally attached replica as a result of 15 MPa masticatory pressure; full view (left) and close-up view showing the crestal bone (right). Unit is Pa. Figure 11. Strains generated in cortical bone surrounding periodontally attached replica as a result of 15 MPa masticatory pressure; full view (left) and close-up view showing the crestal bone (right). Unit is strain. One strain = 106 micro strain. Figure 12. Von Mises stress (SEQV) generated in body of periodontally attached replica as a result of 15 MPa masticatory pressure. (a) Mesial and apical aspect. (b) Lingual aspect. (c) Distal and occlusal aspect. (d) Buccal aspect. Unit is Pa.
Figure 13. Von Mises stress (SEQV) generated in cancellous bone surrounding osseointegrated replica as a result of 23 MPa masticatory pressure; full view (left) and close-up view showing inside the socket (right). Unit is Pa. Figure 14. Strains generated in cancellous bone surrounding osseointegrated replica as a result of 23 MPa masticatory pressure; full view (left) and close-up view showing inside the socket (right). Unit is strain. One strain = 106 micro strain. Figure 15. Von Mises stress (SEQV) generated in cortical bone surrounding osseointegrated replica as a result of 23 MPa masticatory pressure; full view (left) and close-up view showing the crestal bone (right). Unit is Pa. Figure 16. Strains generated in cortical bone surrounding osseointegrated replica as a result of 23 MPa masticatory pressure; full view (left) and close-up view showing the crestal bone (right). Unit is strain. One strain = 106 micro strain. Figure 17. Von Mises stress (SEQV) generated in body of osseointegrated replica as a result of 23 MPa masticatory pressure. (a) Mesial and apical aspect with close-up view of region of maximum stress (top left). (b) Lingual aspect with close-up view of region of maximum stress (top right). (c) Distal and occlusal aspect. (d) Buccal aspect. Unit is Pa.
Figure 23. Von Mises stress (SEQV) generated in cancellous bone surrounding periodontally attached replica as a result of 80 N masticatory force; full view (left) and close-up view showing inside the socket (right). Unit is Pa. Figure 24. Strains generated in cancellous bone surrounding periodontally attached replica as a result of 80 N masticatory force; full view (left) and close-up view showing inside the socket (right). Unit is strain. One strain = 106 micro strain. Figure 25. Von Mises stress (SEQV) generated in cortical bone surrounding periodontally attached replica as a result of 80 N masticatory force; full view (left) and close-up view showing the crestal bone (right). Unit is Pa. Figure 26. Strains generated in cortical bone surrounding periodontally attached replica as a result of 80 N masticatory force; full view (left) and close-up view showing the crestal bone (right). Unit is strain. One strain = 106 micro strain. Figure 27. Von Mises stress (SEQV) generated in body of periodontally attached replica as a result of 80 N masticatory force. (a) Mesial and apical aspect with close-up view of region of maximum stress at the apex. (b) Lingual aspect. (c) Distal and occlusal aspect. (d) Buccal aspect. Unit is Pa.
Figure 28. Von Mises stress (SEQV) generated in cancellous bone surrounding osseointegrated replica as a result of 217 N masticatory force; full view (left) and close-up view showing inside the socket (right). Unit is Pa. Figure 29. Strains generated in cancellous bone surrounding osseointegrated replica as a result of 217 N masticatory force; full view (left) and close-up view showing inside the socket (right). Unit is strain. One strain = 106 micro strain. Figure 30. Von Mises stress (SEQV) generated in cortical bone surrounding osseointegrated replica as a result of 217 N masticatory force; full view (left) and close-up view showing the crestal bone (right). Unit is Pa. Figure 31. Strains generated in cortical bone surrounding osseointegrated replica as a result of 217 N masticatory force; full view (left) and close-up view showing the crestal bone (right). Unit is strain. One strain = 106 micro strain. Figure 32. Von Mises stress (SEQV) generated in body of osseointegrated replica as a result of 217 N masticatory force. (a) Mesial and apical aspect. (b) Lingual aspect. (c) Distal and occlusal aspect. (d) Buccal aspect with close-up view of region of maximum stress (top). Unit is Pa.
Figure 33. Diagrammatic representation showing the resulting maximum Von Mises stress (max SEQV in MPa) in each component of the models involved in the study as a response to each 1-MPa pressure load. Figure 34. Diagrammatic representation showing the resulting maximum Von Mises stress (max SEQV in MPa), in each component of the models involved in the study, as a response to each 1-N point force load.
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