New insights in the 3-D rheological properties and collagen fibers orientation in murine periodontal ligaments
Abstract
The rheological properties of the periodontal ligament are key parameters to understand the
homeostatic stability of the tooth supporting apparatus. The objective of this study is to lay new
insights on the rheological properties and structural information of different regions in murine
periodontal ligament by using atomic force (AFM) and multi-photon microscopy (MPM). A significant
variation in elasticity of different regions was measured. The elasticity of periodontal
ligament showed a significant tendency to become softer towards the furcation, the nearest area
to the center of resistance of the tooth. This can open a new prospective for connecting the
rheological adaptation of periodontal ligament to the tooth geometry that defines the center of
resistance. Another important finding revealed by the second harmonic generation (SHG) signal
exhibited by collagen fibers and measured by MPM is that the orientation of fibers in the furcation
region can both provide space for tooth vertical movement with high compressive loads and
prevent horizontal tooth movement. Additionally, it was found that the dispersion of the angles at
different levels of cutting indicates homogeneity in the directionality of fibers across different
regions. These results provide an accurate description of the rheological properties and structural
information of periodontal ligament, which can serve as a base for comparison with other local
and systemic diseases that may influence the periodontal ligament.