Journal ArticleDOI
The Mechanical Properties of Human Dentin: a Critical Review and Re-evaluation of the Dental Literature:
TLDR
A critical re-evaluation of the literature indicates that the magnitudes of the elastic constants of dentin must be revised considerably upward, and the large coefficients of variation cited in all strength studies can be understood in terms of a distribution of flaws within the dentin specimens.Abstract:
The past 50 years of research on the mechanical properties of human dentin are reviewed. Since the body of work in this field is highly inconsistent, it was often necessary to re-analyze prior studies, when possible, and to re-assess them within the framework of composite mechanics and dentin structure. A critical re-evaluation of the literature indicates that the magnitudes of the elastic constants of dentin must be revised considerably upward. The Young's and shear moduli lie between 20-25 GPa and 7-10 GPa, respectively. Viscoelastic behavior (time-dependent stress relaxation) measurably reduces these values at strain rates of physiological relevance; the reduced modulus (infinite relaxation time) is about 12 GPa. Furthermore, it appears as if the elastic properties are anisotropic (not the same in all directions); sonic methods detect hexagonal anisotropy, although its magnitude appears to be small. Strength data are re-interpreted within the framework of the Weibull distribution function. The large coefficients of variation cited in all strength studies can then be understood in terms of a distribution of flaws within the dentin specimens. The apparent size-effect in the tensile and shear strength data has its origins in this flaw distribution, and can be quantified by the Weibull analysis. Finally, the relatively few fracture mechanics and fatigue studies are discussed. Dentin has a fatigue limit. For stresses smaller than the normal stresses of mastication, approximately 30 MPa, a flaw-free dentin specimen apparently will not fail. However, a more conservative approach based on fatigue crack growth rates indicates that if there is a pre-existing flaw of sufficient size (approximately 0.3-1.0 mm), it can grow to catastrophic proportion with cyclic loading at stresses below 30 MPa.read more
Citations
More filters
Journal ArticleDOI
Structural Design Elements in Biological Materials: Application to Bioinspiration
TL;DR: Eight structural elements in biological materials are identified as the most common amongst a variety of animal taxa and can serve as a toolbox for rationalizing the complex mechanical behavior of structural biological materials and for systematizing the development of bioinspired designs for structural applications.
Journal ArticleDOI
Nanoindentation of biological materials
TL;DR: This work has shown that indentation data analysis can be used to investigate variations in mechanical properties with changes in tissue organization or composition in mineralized and soft tissues, and map mechanical properties spatially in complex biomaterials.
Journal ArticleDOI
Physico-mechanical characteristics of commercially available bulk-fill composites.
Julian Leprince,William M. Palin,Julie Vanacker,Joseph Sabbagh,Jacques Devaux,Gaëtane Leloup +5 more
TL;DR: A compromise with mechanical properties compared with more conventional commercially-available nano-hybrid materials was demonstrated by the present work, which highlights the critical requirement for a veneering material, not only to improve aesthetic quality of the translucent material, but to reduce the impact of degradation.
Journal ArticleDOI
Finite element analysis of stresses in endodontically treated, dowel-restored teeth
TL;DR: Within the limitations of this study, it was found that all investigated dowel-related factors influenced the stress field generated in dowEL-restored teeth.
Journal ArticleDOI
Dentin bonding—Variables related to the clinical situation and the substrate treatment
TL;DR: A new approach to stop the degradation of dentin-resin interfaces is the use of MMP inhibitors, although still in an early phase of in vitro and clinical research, this method is promising.
References
More filters
Journal ArticleDOI
An improved technique for determining hardness and elastic modulus using load and displacement sensing indentation experiments
Warren C. Oliver,George M. Pharr +1 more
TL;DR: In this paper, the authors used a Berkovich indenter to determine hardness and elastic modulus from indentation load-displacement data, and showed that the curve of the curve is not linear, even in the initial stages of the unloading process.
Book
Viscoelastic properties of polymers
TL;DR: In this article, the authors describe the nature of Viscoelastic behavior of polymeric systems and approximate relations among the linear Viscoels and approximate interrelations among the Viscelastic Functions.
Book
Physical properties of crystals
TL;DR: In this paper, the physical properties of crystals systematically in tensor notation are presented, presenting tensor properties in terms of their common mathematical basis and the thermodynamic relations between them.
Journal ArticleDOI
A method for interpreting the data from depth-sensing indentation instruments
M. F. Doerner,William D. Nix +1 more
TL;DR: In this paper, a method for obtaining hardness and Young's modulus from the data obtained from these types of instruments is described, where the elastic displacements are determined from data obtained during unloading of the indentation.