Single-beam, dual-view digital holographic interferometry for biomechanical strain measurements of biological objects

Abstract

We describe a method for dual-view biomechanical strain measurements of highly asymmetrical biological objects, like teeth or bones. By using a spherical mirror, we were able to simultaneously record a digital hologram of the object itself and the mirror image of its (otherwise invisible) rear side. A single laser beam was sufficient to illuminate both sides of the object, and to provide a reference beam. As a result, the system was mechanically very stable, enabling long exposure times (up to 2 min) without the need for vibration isolation. The setup is simple to construct and adjust, and can be used to interferometrically observe any object that is smaller than the mirror diameter. Parallel data processing on a CUDA-enabled (compute unified device architecture) graphics card was used to reconstruct digital holograms and to further correct image distortion. We used the setup to measure the deformation of a tooth due to mastication forces. The finite-element method was used to compare experimental results and theoretical predictions.

Influence of restorative procedures on endodontically treated premolars: Finite element analysis of a CT-scan based three-dimensional model

“…Since the purpose of the present FEA study was to evaluate von Mises stress values and distribution in models of endodontically treated teeth with different restoration protocols in the physiological biting position, the current experiment setting was adequate for achieving this goal. The present FEA model was validated in an experimental study with a specific setup for the measurement of strain using dualview holographic interferometry 45) . Due to the difficulty in collecting a homogenous sample of human premolars, it was performed on plastic tooth models created using rapid prototyping based on the FEA model.…”

Novel biophotonics-based techniques in dental medicine - a literature review

“…The DHI is a laser optic technique suitable for the submicron measurement of surface deformations in a contactless and non-destructive manner [24]. The basic principle of holographic interferometry considers recording sample images (holograms) at two states, before and after mechanical load, and interference of the resulting holograms visualizing the displacement field of the object [25][26][27].…”

Microtissue engineering root canal dentine with crosslinked biopolymeric nanoparticles for mechanical stabilization

“…Photomechanical techniques such as digital photoelasticity, digital moiré interferometry, electronic speckle pattern interferometry and digital image correlation are applied in dental biomechanics to study stress–strain response in intact (Wang & Weiner , Kishen & Asundi ,b, Pantelić et al . ) and restored root filled teeth (Lang et al . , Pantelić et al .…”