Effect of biomechanical load factors on the stress-strain state of teeth and underlying bone tissue

Abstract

Background: The biomechanical conditions under which teeth, implants, and bone tissue function clearly determine their resistance to overloading and subsequent destruction. However, mathematical modeling has not previously been used to compare functional stress in teeth across a wide range of sensitive biomechanical load conditions. Aim: To compare the stress-strain state parameters of tooth and socket tissues under various biomechanical load conditions. Materials and methods: A mathematical model was used to assess the stress-strain state parameters of dental tissue and sockets under vertical and oblique load (150N) with various modeling settings, compared to reference model parameters. The following parameters were assessed: enamel attrition, bone density reduction, bone resorption by 30% and 50%, supra-occlusion, tooth cavity, composite restoration, and ceramic inlay. Results: Enamel attrition significantly increases stress under vertical and oblique loads: 1.9 and 1.6 times for enamel, and 1.5 and 1.2 times for dentin, respectively. Tooth cavities increase stress by 1.2 and 1.8 times (enamel; vertical and oblique loads, respectively), and 1.3 times (dentin; vertical load). Increased functional load causes a proportional increase in stress in hard tooth tissues and adjacent bone tissues. Supra-occlusion causes a sharp increase in stress in the enamel, with a point stress concentration. When a tooth cavity is filled with a composite or ceramic material, the stress-strain state parameters are similar to those in intact teeth (however, the enamel still experiences a 1.5-fold increase in stress under vertical pressure). Conclusion: 3D mathematical modeling revealed a significant difference in maximum stress in tooth and socket tissues compared to normal biomechanical conditions, as well as when comparing various sensitive load conditions. Stress in tooth and bone tissues increased in all cases of abnormal biomechanical conditions, especially when oblique load was applied.