Hardness, an Important Indicator of Bone Quality, and the Role of Collagen in Bone Hardness

Abstract

Bone is a nanocomposite material where the hard inorganic (hydroxyapatite crystallites) and organic (collagen fibrils) components are hierarchically arranged in the nanometer scale. Bone quality is dependent on the spatial distributions in the shape, size and composition of bone constituents (mineral, collagen and water). Bone hardness is an important property of bone, which includes both elastic and plastic deformation. In this study, a microhardness test was performed on a deer bone samples. The deer tibia shaft (diaphysis) was divided into several cross-sections of equal thickness; samples were prepared in untreated, boiled water treatment (100 °C for 30 min) and sodium hypochlorite (NaOCl) treatment conditions. Microhardness tests were performed on various regions of the tibial diaphysis to study the heterogeneous characteristics of bone microhardness and highlight the role of the organic matrix in bone hardness. The results indicated that boiled water treatment has a strong negative correlation with bone hardness. The untreated bone was significantly (+20%) harder than the boiled-water-treated bone. In general, the hardness values near the periosteal surface was significantly (23 to 45%) higher than the ones near the endosteal surface. Samples treated with NaOCl showed a significant reduction in hardness.

Osteocyte β1 integrin loss causes low bone mass and impairs bone mechanotransduction in mice

“…The elastic modulus, often known as Young's modulus, is an intrinsic material property of bone which is related to the resistance offered by the bone to elastic deformations. Hardness is an engineering property in characterization of bone microstructures and its resistance to penetration, which has been shown with great associations to bone matrix composition, such as collagen fibers [ 45 , 46 ]. To further examine the bone mechanical properties of the two genotypes in nano- and micro-scale, we applied the nanoindentation approach to evaluate both Young's modulus and hardness of non-decalcified tibial samples from control and cKO male mice ( Fig.…”

Tooth hop variability in human and nonhuman bone: Effect on the estimation of saw blade TPI

“…This seems to reflect expected differences in bone hardness. Adult human bone from various sources has been shown to have similar hardness values consistent with the adult pig bone (sows around 3 years old) as presented by Bonney and Goodman [29], whereas adult deer bone tends to be harder due to variations in the degree of mineralization and collagen [33].…”

Calcimimetics Alter Periosteal and Perilacunar Bone Matrix Composition and Material Properties in Early Chronic Kidney Disease

“…Hardness is reflective of the ability of a material to resist plastic/permanent deformation, a property that depends on the organic components of the bone matrix including collagen and water and has been correlated with higher mineralization. ( 31 ) Although higher MMR and crystallinity typically increase reduced elastic modulus and lower hardness, it is possible that collagen content/quality and/or bound water were also higher in these regions to compensate for the increased mineralization. Future studies specifically interrogating the role of collagen quality and hydration in bone material properties in CKD are warranted.…”