Processing and properties of hydroxyapatite-based biomaterials for use as hard tissue replacement implants

Abstract

This paper reviews the past, present, and future of the hydroxyapatite (HAp)-based biomaterials from the point of view of preparation of hard tissue replacement implants. Properties of the hard tissues are also described. The mechanical reliability of the pure HAp ceramics is low, therefore it cannot be used as artificial teeth or bones. For these reasons, various HAp-based composites have been fabricated, but only the HAp-coated titanium alloys have found wide application. Among the others, the microstructurally controlled HAp ceramics such as fibers/whiskers-reinforced HAp, fibrous HAp-reinforced polymers, or biomimetically fabricated HAp/collagen composites seem to be the most suitable ceramic materials for the future hard tissue replacement implants.

Self‐hardening calcium phosphate composite scaffold for bone tissue engineering

“…It is possible that when implanted in vivo, the strengthening of the graft from bone ingrowth may offset the weakening of the graft due to fiber dissolution [ 18,3 1,401. For example, the flexural strength of available sintered porous hydroxyapatite implants ranged from 2 to 11 MPa; it then increased when new bone grew into the macropores of the hydroxyapatite implants, reaching 40-60 MPa [37]. Alternatively, to achieve a gradual loadsharing transfer, fibers and fillers of different dissolution rates could be combined in the self-hardening and resorbable apatite scaffold, with fast-dissolution fillers to dissolve in a couple of days upon contact with the physiological solution in vivo to immediately create macropores for bone ingrowth.…”

“…The need for biomaterials has increased as the world population ages [16,25,37]. Bone grafts have been used for decades to repair osseous defects resulting from trauma and disease and over 800,000 grafting procedures are performed each year [25].…”

“…Bone grafts have been used for decades to repair osseous defects resulting from trauma and disease and over 800,000 grafting procedures are performed each year [25]. Hydroxyapatite is an important biomaterial for hard tissue repair because of its chemical and crystallographic similarity to the carbonated apatite in teeth and bones [16,18,37]. Several calcium phosphate cements (CPCs) self-harden to form hydroxyapatite [5,8,14,29].…”

Physical Properties of Nano-HAs/ZrO2 Coating on Surface of Titanium Materials Used in Dental-implants and its Biological Compatibility

“…HAs can also incorporate with all biological tissues in virtue of interface reaction and hydrogen bonds [1][2][3][4][5][6][7] . HAs can release the free calcium and phosphorus through the degradation, when are in a solution of organism, thus HAs can be easily absorbed by the biological tissues to stimulate the growth of tissues, bone and tooth in living system.…”

Nanonstructural Analysis of Hydroxyapatite Thin Films Using HRTEM/FIB Techniques

“…

Hydroxyapatite, with a composition that resembles the mineral phase of bone, is often used as a coating of metallic prostheses to improve the adhesion and osseointegration of implants in different parts of the skeleton [1]. Among the available techniques that allow the deposition of this material on metallic substrates, Pulsed Laser Deposition (PLD) is capable of producing high quality and highly biocompatible coatings with excellent final attachment [2,3].

In the present work, the hydroxyapatite coatings were deposited on titanium substrates by PLD, keeping the substrate temperature at 460 ºC and carrying the process under a low-pressure water vapour atmosphere.

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