IADR Abstract Archives
Reduced functional loads inversely affect the quality of interradicular bone
Objectives: The shifts in biomechanics of the dentoalveolar fibrous joint due to reduced functional loads will be explained through a coupled effect termed as “quality” resulting from changes in form (at an organ-level) and material properties (at a tissue-level) of the load-bearing interradicular alveolar bone (IB)
Methods: 4 week old Sprague Dawley rats (N=60) were given either hard pellets (HD) or a soft powder (SD). Changes in biomechanics of the fibrous joints, functional space, and distribution of osteoclasts were analyzed by raising the two groups to 8,12,16,20, or 24 weeks (Jang et al., 2015). The architecture/form of IB was quantified by measuring bone volume fraction (BVF) from X-ray tomograms. Digital volume correlation (DVC) was performed on tomograms of fibrous joints to investigate the strain in adapted IB from respective groups. Elastic modulus values of IB from hard and soft diet groups were obtained under wet conditions using nanoindentation technique.
Results: A significant reduction in functional space (90µm) was observed in the interradicular region of fibrous joints from SD group. Minimal changes in osteoclast activity were observed within the IB of the SD group, however significantly decreased BVF (24wk-HD:0.87+0.02, SD:0.78+0.05,P<0.05,Student’s t-test) and reduced elastic modulus (Er) of IB (12wk-HD:14+7GPa,SD:10+4GPa,P<0.05, Student’s t-test) were seen in SD group as a function of age and hardness of food. Increased maximum principal strain was observed in 8 week-IB adapted to SD compared to HD at lower loads.
Conclusions: Observed changes indicated that adaptive processes within the interradicular region are regulated during earlier ages of the mammal. Results demonstrated that optimization of form and material properties of the IB to meet functional demands placed on the joint are age dependent. Although changes in form and material properties are mutually dependent, collectively, these physical properties could be inversely related with age and can affect the functional quality of IB.
Methods: 4 week old Sprague Dawley rats (N=60) were given either hard pellets (HD) or a soft powder (SD). Changes in biomechanics of the fibrous joints, functional space, and distribution of osteoclasts were analyzed by raising the two groups to 8,12,16,20, or 24 weeks (Jang et al., 2015). The architecture/form of IB was quantified by measuring bone volume fraction (BVF) from X-ray tomograms. Digital volume correlation (DVC) was performed on tomograms of fibrous joints to investigate the strain in adapted IB from respective groups. Elastic modulus values of IB from hard and soft diet groups were obtained under wet conditions using nanoindentation technique.
Results: A significant reduction in functional space (90µm) was observed in the interradicular region of fibrous joints from SD group. Minimal changes in osteoclast activity were observed within the IB of the SD group, however significantly decreased BVF (24wk-HD:0.87+0.02, SD:0.78+0.05,P<0.05,Student’s t-test) and reduced elastic modulus (Er) of IB (12wk-HD:14+7GPa,SD:10+4GPa,P<0.05, Student’s t-test) were seen in SD group as a function of age and hardness of food. Increased maximum principal strain was observed in 8 week-IB adapted to SD compared to HD at lower loads.
Conclusions: Observed changes indicated that adaptive processes within the interradicular region are regulated during earlier ages of the mammal. Results demonstrated that optimization of form and material properties of the IB to meet functional demands placed on the joint are age dependent. Although changes in form and material properties are mutually dependent, collectively, these physical properties could be inversely related with age and can affect the functional quality of IB.
2411320_File000001.jpg