Pentosidine correlates with nanomechanical properties of human jaw bone

Initial intimate apposition between implant fixtures and host bone at the surgical site is a critical factor for osseointegration of dental implants. The advanced glycation end products accumulated in the jaw bone could lead to potential failure of a dental implant during the initial integration stage, because of the inferior bone mechanical property associated with the abnormal collagen cross-linking at the material level. Here, we demonstrate the lowered creep deformation resistance and reduced dimensional recovery of jaw bone in line with high levels of pentosidine accumulation in the bone matrix which likely correlate with the pentosidine level in blood plasma. Peripheral blood samples and cortical bone samples at the surgical site were obtained from patients scheduled for dental implants in the mandible. The pentosidine levels in blood plasma were assessed. Subsequently, the relative pentosidine levels and the mechanical properties of the jaw bone were quantified by Raman microspectroscopy and nanoindentation, respectively. The nanoindentation tests revealed less creep deformation resistance and reduced time-dependent dimensional recovery of bone samples with the increase in the relative pentosidine level in the bone matrix. Higher tan δ values at the various frequencies during the dynamic indentation tests also suggested that viscoelasticity is associated with the relative intensity of pentosidine in the jaw bone matrix. We found a positive correlation between the pentosidine levels in blood plasma and the bone matrix, which in turn reduced the mechanical property of the jaw bone at the material level. Increased creep and reduced dimensional recovery of the jaw bone may diminish the mechanical interlocking of dental implants during the initial integration stage. Given the likely correlation between the plasma pentosidine level and the mechanical properties of bone, measurement of the plasma pentosidine level could serve as a new index to assess jaw bone matrix quality in advance of implant surgery.