Multi-Scale Surface Treatments of Titanium Implants for Rapid Osseointegration: A Review

Abstract

The propose of this review was to summarize the advances in multi-scale surface technology of titanium implants to accelerate the osseointegration process. The several multi-scaled methods used for improving wettability, roughness, and bioactivity of implant surfaces are reviewed. In addition, macro-scale methods (e.g., 3D printing (3DP) and laser surface texturing (LST)), micro-scale (e.g., grit-blasting, acid-etching, and Sand-blasted, Large-grit, and Acid-etching (SLA)) and nano-scale methods (e.g., plasma-spraying and anodization) are also discussed, and these surfaces are known to have favorable properties in clinical applications. Functionalized coatings with organic and non-organic loadings suggest good prospects for the future of modern biotechnology. Nevertheless, because of high cost and low clinical validation, these partial coatings have not been commercially available so far. A large number of in vitro and in vivo investigations are necessary in order to obtain in-depth exploration about the efficiency of functional implant surfaces. The prospective titanium implants should possess the optimum chemistry, bionic characteristics, and standardized modern topographies to achieve rapid osseointegration.

Osteoconductive and Osteoinductive Surface Modifications of Biomaterials for Bone Regeneration: A Concise Review

“…Etching increases roughness and wettability of the implant [121] but exerts negative effect on its mechanical properties [120]. Surface modification technique combining acid-etching and sand blasting is defined as sand-blasted, large-grit, acid etched (SLA), which indicates application of an acid onto the blasted surface [120,122]. SLA allows to obtain macro-roughness and micro-pits, increasing surface area and roughness of the implant, and thereby improving osseointegration [122].…”

“…The size of achieved roughness depends on the size of ceramic particles used for the subtractive modification. The ceramic particles should be stable and biocompatible since residual blasting material particles might be very hard to remove from the sample surface [120,123]. Another processing method of metallic implants is anodizing.…”

“…Moreover, anodizing allows formation of the nanopores and nanotubes to change topographic features of the implant. The changes in the texture of the implant may be controlled by application of various oxidation voltage, oxidation duration, type of electrolyte solution (e.g., H2SO4, HNO3, hydrofluoric acid (HF)), and electrolyte solution concentration [120,124]. Laser treatment of the implants is an innovative surface modification method which allows modification of the surfaces at a nano-, micro-, and Texture modification techniques, such as subtractive methods, allow to modify or change surface characteristics to increase the biocompatibility of biomaterials for bone tissue engineering and regenerative medicine applications.…”

“…Laser treatment of the implants is an innovative surface modification method which allows modification of the surfaces at a nano-, micro-, and Texture modification techniques, such as subtractive methods, allow to modify or change surface characteristics to increase the biocompatibility of biomaterials for bone tissue engineering and regenerative medicine applications. For instance, acid etching method allows to obtain irregular and complex surface of Ti implants using strong acid solutions such as sulfuric acid (H 2 SO 4 ), hydrochloric acid (HCl), hydrofluoric acid (HF), nitric acid (HNO 3 ), and any combination of mentioned acid solutions [120]. Etching increases roughness and wettability of the implant [121] but exerts negative effect on its mechanical properties [120].…”

“…For instance, acid etching method allows to obtain irregular and complex surface of Ti implants using strong acid solutions such as sulfuric acid (H 2 SO 4 ), hydrochloric acid (HCl), hydrofluoric acid (HF), nitric acid (HNO 3 ), and any combination of mentioned acid solutions [120]. Etching increases roughness and wettability of the implant [121] but exerts negative effect on its mechanical properties [120]. Surface modification technique combining acid-etching and sand blasting is defined as sand-blasted, large-grit, acid etched (SLA), which indicates application of an acid onto the blasted surface [120,122].…”