Advances in surfaces and osseointegration in implantology. Biomimetic surfaces

Abstract

The present work is a revision of the processes occurring in osseointegration of titanium dental implants according to different types of surfaces -namely, polished surfaces, rough surfaces obtained from subtraction methods, as well as the new hydroxyapatite biomimetic surfaces obtained from thermochemical processes. Hydroxyapatite’s high plasma-projection temperatures have proven to prevent the formation of crystalline apatite on the titanium dental implant, but lead to the formation of amorphous calcium phosphate (i.e., with no crystal structure) instead. This layer produce some osseointegration yet the calcium phosphate layer will eventually dissolve and leave a gap between the bone and the dental implant, thus leading to osseointegration failure due to bacterial colonization. A new surface -recently obtained by thermochemical processes- produces, by crystallization, a layer of apatite with the same mineral content as human bone that is chemically bonded to the titanium surface. Osseointegration speed was tested by means of minipigs, showing bone formation after 3 to 4 weeks, with the security that a dental implant can be loaded. This surface can be an excellent candidate for immediate or early loading procedures. Key words:Dental implants, implants surfaces, osseointegration, biomimetics surfaces.

Treatments to Optimize Dental Implant Surface Topography and Enhance Cell Bioactivity

“…The most important mechanisms involved are the protein adsorption capacity, wettability, and an optimized zeta potential which reduces the electrostatic dispersion between particles. Finally, this procedure also aims to increase the kinetics of adhesion, proliferation, and differentiation of osteoblast cells compared to other current surface treatments in order to facilitate bone formation around the implants [66][67][68] (Figure 3). Anodic oxidation is an electrolytic process used to strengthen and increase the thickness of the natural oxide layer.…”

“…Anodic oxidation is an electrolytic process used to strengthen and increase the thickness of the natural oxide layer. This passivation technique manages to turn a smooth Ti surface into a tubular nanostructure with diameters below 100 nm [69]. Some authors suggest that by modifying the parameters of voltage, current density, and chemistry of electrolytes, it is possible to control the physical and chemical properties of the implant surfaces, the spacing, and the diameter of nanotubes [70].…”

“…Alkali treatment is a procedure in which the Ti implant is immersed in either potassium or sodium hydroxide followed by heat treatment (800°C for 20 min) and subsequent rinsing with distilled water. This technique achieves a nanostructured and bioactive sodium titanate layer on the surface of the dental implant, which provides favorable conditions for bone marrow cell differentiation [69]. The thermal oxidation works by changing the crystal structure of the nanometric oxide layer and thus increases the bioactivity of a biocompatible metal [79].…”

“…These biological activities are correlated with the thickness of the TiO 2 coating and the oxygen Dental Implantology and Biomaterial 116 saturation of the surface. This means that the biological response of Ti can be improved even with picometer super thin coatings [69].…”

Biocompatibility Analyses of Al2O3-Treated Titanium Plates Tested with Osteocyte and Fibroblast Cell Lines

“…Particular attention has been given in recent decades to the morphology of the surface of titanium implants to overcome the biocompatibility issues [2,15,16]. The importance of the titanium morphology in the proliferation and differentiation of cells in vitro was showed by various authors.…”