Spatio-temporal evolution of hydroxyapatite crystal thickness at the bone-implant interface

Abstract

A better understanding of bone nanostructure around the bone-implant interface is essential to improve longevity of clinical implants and decrease failure risks. This study investigates the spatiotemporal evolution of mineral crystal thickness and plate orientation in newly formed bone around the surface of a metallic implant. Standardized coin-shaped titanium implants designed with a bone chamber were inserted into rabbit tibiae for 7 and 13 weeks. Scanning measurements with microfocused small-angle X-ray scattering (SAXS) were carried out on newly formed bone close to the implant and in control mature cortical bone. Mineral crystals were thinner close to the implant (1.8 ± 0.45 nm at 7 weeks and 2.4 ± 0.57 nm at 13 weeks) than in the control mature bone tissue (2.5 ± 0.21 nm at 7 weeks and 2.8 ± 0.35 nm at 13 weeks), with increasing thickness over healing time (+30 % in 6 weeks). These results are explained by younger bone close to the implant, which matures during osseointegration. Thinner mineral crystals parallel to the implant surface within the first 100 µm close to the implant indicate that the implant affects bone ultrastructure close to the implant, potentially due to heterogeneous interfacial stresses, and suggest a longer maturation process of bone tissue and difficulty in binding to the metal. The bone growth kinetics within the bone chamber was derived from the spatio-temporal evolution of bone tissue's nanostructure, coupled with microtomographic imaging. The findings indicate that understanding mineral crystal thickness or plate orientation can improve our knowledge of osseointegration.

Neutron microtomography to investigate the bone-implant interface—comparison with histological analysis

“…In addition to the possible technical improvements discussed above, this study is based on four bone-implant specimens coming from one single animal. Nonetheless, the coin-shaped implant model has been validated in former studies, revealing comparable bone content and BIC values as quantified by histological slices after 13 weeks of healing (Fraulob et al, 2020a;Le Cann et al, 2020;Mathieu et al, 2011;Vayron et al, 2014).…”

“…To further investigate local variations in the bone-implant interface formation, this reference coin-shaped implant model has been modified by our group to include a bone chamber which allow a clear distinction between mature and newly formed bone tissues. Adopting this implant model, it was possible to explore the spatiotemporal variations of the mechanical (Fraulob et al, 2020a;Mathieu et al, 2011;Vayron et al, 2011Vayron et al, , 2012Vayron et al, , 2014, structural (Le Cann et al, 2020) and compositional properties (Fraulob et al, 2020b) of bone.…”

Efficiency of Nanohydroxyapatite on Repairing Type II Diabetes Dental Implant-Bone Defect

“…At present, the most common polymer composite materials include hydroxyapatite (HA), polyamide, and polylactic acid, among which HA has good biocompatibility. Nevertheless, its strength is low and brittleness is high, so its damage resistance is not high in the actual physiological environment [ 22 ]. To meet the needs of bone scaffold materials, porous artificial bone materials with nanometer HA and PA66 were prepared.…”

The First Experience With the Use of Ceramic Implants Saturated With Autological Bone Marrow Stromale Cells (Case Study)

“…После проведения эксперимента на животных в Италии стала вполне ясной перспектива возможного применения керамических имплантатов, насыщенных аутологичными стромальными клетками костного мозга, у людей. Данные эксперимента позднее были подтверждены целым рядом работ [4][5][6]. После прохождения локального этического комитета с целью решения вопроса о возможности применения методики, на основании решения профильной проблемной комиссии и Ученого совета организаций, принявших участие в работе, а также при наличии согласия пациента на оперативное лечение и использование стволовых клеток больные включались в группу исследования.…”