Bone growth is enhanced by novel bioceramic coatings on Ti alloy implants

Abstract

Calcium phosphate ceramics are widely used as coating materials to orthopedic implants and are found to enhance initial bony ingrowth by stimulating osseous apposition to the implant surface. In this study, two novel calcium orthophosphate materials were selected for coating onto the commonly used orthopedic implant material Ti-6Al- 4V. One was calcium alkali orthophosphate with the crystalline phase Ca10[K/Na](PO4)7 with a small addition of SiO2 (AW-Si) and the other was calcium orthophosphate composed of 70 mol % fluorapatite, Ca10(PO4)6F2 and 30 mol % CaZr4(PO4)6 (FA7Z). The coated implants were placed in cortical and cortico-cancellous bone of sheep femur for six weeks. Retrieved samples were tested for osseointegration and mechanical strength. It was found that both coatings produced enhanced bone/implant contact rate compared to the control when implanted in cortico-cancellous bone. This study demonstrates that the two coatings have the capability of encouraging bone growth, and hence the potential for being used as coating materials on Ti implants.

Calcium orthophosphate deposits: Preparation, properties and biomedical applications

“…properties of adjacent bones [897], show higher torque values [881,886,896,898] and push-out strength [899], seal the interface from wear particles [900], facilitate bridging of small gaps [901,902], reduce ion release from the metallic substrates [806,[903][904][905], slow down metal degradation and/or corrosion [38,42,72,73,414,791,[906][907][908], accelerate bone growth [909][910][911], remodeling [912,913] and osteointegration [35,437,480,767,[914][915][916][917], improve biocompatibility [918], induce osteoconductivity [846,[919][920][921][922], osteoinductivity [923] and osteogenesis [130,889,896,924,…”

Calcium orthophosphate coatings, films and layers

“…Since then, plentiful reports have been published about the biomedical advantages of such coated implants. To summarize the available information on the biomedical and biomechanical properties of implants coated by calcium orthophosphates, one can claim the following: If compared to uncoated implants, the presence of calcium orthophosphate deposits were found to induce bone contacts to the implants (Dhert et al 1992, 1993; Thomas et al 1989; Jansen et al 1991; Gottlander et al 1997b; Hulshoff and Jansen 1997; Hayakawa et al 2000; Mohammadi et al 2004; Park et al 2005; Siebers et al 2007; Kuroda et al 2007; Chae et al 2008; Schwarz et al 2009; Junker et al 2010; Suzuki et al 2010); improve implant fixation (Yang et al 1997; Søballe et al 1993; Daugaard et al 2010); show higher torque values (Park et al 2005; Junker et al 2010; Granato et al 2009) and push-out strength (Ozeki et al 2001); facilitate bridging of small gaps between implants and surrounding bones (Søballe et al 1991; Stephenson et al 1991), reduce metal ion release from the metallic substrates (Surmenev et al 2010; Ducheyne and Healy 1988; Sousa and Barbosa 1996; Ozeki et al 2003); slow down metal degradation and/or its corrosion (Metikoš-Huković et al 2003; Yang et al 2008; Cheng and Roscoe 2005); accelerate bone growth (Cook et al 1992; Wang et al 2009), remodeling (Pilliar et al 1991; Yoon et al 2009) and osteointegration rate (Bigi et al 2008; Lee et al 2011); induce osteoconductivity (Cao et al 2010b), improve the early bone (Yang et al 1996; Mohammadi et al 2003) and healing (Vercaigne et al 2000b) responses; and result in lack of formation of fibrous tissues (Figure 11) (Layrolle 2011; Dostálová et al 2001), as well as increase the clinical performance of orthopedic hip systems (see below). In addition, calcium orthophosphate coatings, films and layers might be used for incorporation of drugs and important biologically active compounds, such as peptides, hormones and growth factors (Siebers et al 2006).…”

Processing and Properties of BioCeramic Coatings onto 3D Ti‐Mesh by DipCasting Method

“…Titanium (Ti) and its alloys have been widely accepted as reliable dental and orthopedic implant materials due to their excellent mechanical properties required for surgical handing and load‐bearing ability and acceptable elastic moduli relatively close to that of a natural bone . It has also been found that bioceramic‐coated Ti performed better than uncoated Ti‐implants, as relevant osteoconduction and osseointegration properties of the bioceramic‐coated Ti‐implants are noticeably improved. As a result, various bioconductive and bioresorbable ceramics, such as glass‐ceramics, calcium phosphate (CaP) ceramics, and hydroxyapatite (HA) Ca 10 (PO 4 ) 6 (OH) 2 , have been tested and used as bioceramic coatings on Ti‐implants because bone regeneration promoted by resorbable bioceramics better connects the Ti‐implants and surrounding bone structures …”