02632nam a2200277Ia 4500 MX-MdCICY 20260521091422.0 CICY B-14486 Strengthening mechanisms of bone bonding to crystalline hydroxyapatite in vivo BioMaterials, 25(18), p.4243-4254, 2004 The formation and strengthening mechanisms of bone bonding of crystalline hydroxyapatite (HA)has been investigated using high-resolution transmission electron microscope (HRTEM)and energy-dispersive X-ray (EDX)analysis.A series of results were obtained: (i)a layer of amorphous HA, which has almost the same chemistry as the implanted HA, was formed on the surface of crystalline HA particles prior to dissolution; (ii)at 3 months a bone-like tissue formed a bonding zone between mature bone and the HA implant, composed of nanocrystalline and amorphous apatite; and (iii)at 6 months, mature bone was in direct contact with HA particles, and collagen fibres were perpendicularly inserted into the surface layer of implanted HA crystals.Findings (i)and (ii)indicated the following dissolution-precipitation process.(i)The crystalline HA transforms into amorphous HA; (ii)the amorphous HA dissolves into the surrounding solution, resulting in over-saturation; and (iii)the nanocrystallites are precipitated from the oversaturated solution in the presence of collagen fibres.A preliminary analysis indicated several conclusions: (i)the transition from crystalline to amorphous HA might be the controlling step in the bone bonding of crystalline HA; (ii)biological interdigitation (or incorporation)of collagen fibres with HA and chemical bonding of a apatite layer were both necessary to strengthen and toughen a bone bond, not only for the bonding between bone and HA at 6 months, but also for the bonding zone at 3 months, which would otherwise be very fragile due to the inherited brittleness of polycrystalline ceramics; and (iii)perpendicular interdigitation is an effective way for collagen fibres to impart their unique combination of flexibility and strength to the interface which they are keying HYDROXYAPATITE BONE INTERFACE IN VIVO HRTEM Chen, Q.Z. Wong, C.T. Lu, W.W. Cheung, K.M.C. Leong, J.C.Y. https://drive.google.com/file/d/1d0IgaTrXiGkkN_8CzhPXPQGga7Gxr-oL/view?usp=drivesdk Para ver el documento ingresa a Google con tu cuenta: @cicy.edu.mx Loc REF1 250602s9999 xx |||||s2 |||| ||und|d 24613 24613 0 0 Loc 0 0 F1 CICY CICY RE 2025-06-25 0 B-14486 2025-06-25 15:39:42 2025-06-25 REF1