Bone response to alteration of surface topography and surface composition of sandblasted and acid etched (SLA) implants

Abstract

The titanium surface obtained by sandblasting and etching (SLA) is an easily alterable surface that smears and loose its typical texture. In addition, the etching process modifies the surface composition of commercially pure titanium; the latter contains titanium and an added 20-40% of titanium hydride. Therefore, the influence of a heavy surface alteration and the influence of the composition at the SLA surface, i.e. with and without titanium hydride, were investigated in vivo. Three implant groups were inserted in the mandible of Land Race pigs and left to heal during 10 weeks in a submerged way: (1). a standard SLA control group (SLAstd) with the SLA surface containing titanium hydride; (2). a test group with the SLA surface heavily altered at the thread level (SLAalt); (3). a test group with an SLA surface devoid of titanium hydride (SLAT). Sample size was n = 8. Histomorphometry analysis did not show a statistically significant difference between the control group (SLAstd: 82.12 + 6.1%), the altered surface test group (SLAalt: 86.25 + 7.4%) and the SLA without titanium hydride test group (SLAT: 75.12 + 7.6%). The data suggest that alteration of the SLA surface, if it occurs, should not be detrimental to bone response. The soft and easy smearable SLA surface might even be an advantage when surface maintenance is required. Surface composition did not play a significant role in the bone response to the SLA surface and it can therefore be concluded that the osteophilic properties of the SLA surface are due to its surface topography and not to its specific surface composition.

Surface Properties and Biocompatibility of Acid-etched Titanium

“…Perrin et al 12) also reported that the presence of a high and unusual amount hydrogen in etched titanium did not play a significant role in bone response. Therefore, differences in cell proliferation cannot be explained by surface properties such as roughness and composition.…”

“…This is due to the high surface roughness of SLA produced by grit blasting and acid etching, with the latter resulting in an increase in sub-surface hydrogen concentration and the formation of titanium hydride 10) . Surface topology is an important factor for biological interactions at the interface between implants and living tissue 11,12) . In the same vein, surface wettability is another important factor that influences the interactions between the implant surface and the surrounding environment 13,14) .…”

Surface changes of anodic oxidized orthodontic titanium miniscrew

“…Scanning electron microscopy (SEM) demonstrated that these shiny spots correspond to smearing of the soft surface with alteration of the microtopography. 9 This trait is not specific to the SLA surface but rather is common to all etched surfaces. The etching process carves the titanium surface at a depth of 2 to 5 mm and leaves a soft and smearable surface.…”

3D, chemical and electrochemical characterization of blasted TI6Al4V surfaces: Its influence on the corrosion behaviour

“…In some studies, the efforts are being steered towards separating the effects of surface chemistry and topography [13,14] on the response of osteoblasts, in which the roughness is varied but the chemical composition is maintained constant. In other studies [15,16], acid treatments have been applied after the blasting process and thus obtaining a micro roughness on the surface and a reduction of the number of particles remaining on the surface. Nevertheless, it is not clear that the presence of the particles remaining after the blasting process on the surface can produce a deleterious effect on the in vivo implantation.…”