Projet de Recherche POROSITEETH

Connectomic analysis of the cellular porosity network in teeth dentin

Group :  Information, Signal, Image and Life Sciences

Labelling: none

Duration: 48 months

Funding: ANR

Staff involved from LARIS: David ROUSSEAU

Project partners: Aurélien GOURRIER (project leader), Sylvie COSTREL and Irène WANG from the Laboratoire Interdisciplinaire de Physique à l'Université Grenoble-Alpes, Nicolas TREMBLAY from the laboratoire Grenoble Images Parole Signal Automatique de l'Institut Polytechnique de Grenoble, Elsa VENNAT from the Laboratoire de Mécanique Paris-Saclay à CentralSupélec

Abstract

This interdisciplinary project aims to fill a gap in our understanding of the fundamental mechanisms of dental sensitivity. The overall objective is to demonstrate that dentinal porosity, in which physiological fluids circulate, constitutes a complex network that defines the spatial extension of mechanically stimulated cells. This connectomic approach requires extracting a graph representation of the sub-microscopic porosity network relevant at the centimetric scale of the human tooth. As this is technically impossible with current imaging instruments, we will develop super-resolution generative AI models to extend the capabilities of confocal and two-photon optical microscopy which is widely used in mineralized tissue biology laboratories. Graph analysis of the cellular porosity network is a second major challenge. With an estimated 10^7 nodes and links, the calculation of classical metrics would require considerable computational resources. We will therefore test several dimensionality reduction approaches based, in particular, on the biology of the system, by integrating the network's multi-scale and geometric characteristics. These graphs will then be used to model the fluidic circuit and obtain shear stress values that will be compared with experimentally measured mechanosensing thresholds to analyze the spatial modes of cellular activation. Two types of stimuli will be investigated : local (e.g. in dental or hypersensitivity) and global (e.g. in mastication). The effect of progressive alteration of the network by occlusion during aging will also be studied. Our ambition is to establish the tools and knowledge that will serve as the basis for more applied studies combining imaging and modeling to better understand and treat major pathologies in dentistry, some of which represent a major public health issue.