Surface characteristics are key to the body’s response to the implant and abutment that you place in your patient.1 2 Ultimately, it could decide whether your mission for tissue integration succeeds or fails, both for early healing and long-term stability.3

This is why the surface treatment chosen by your implant and abutment manufacturer is so important: their engineering determines those crucial surface characteristics.

Despite the importance of changes to the surface, to the naked eye, it might be difficult to see such a difference – other than a different shade of gray, depending on the treatment process. However, with the recently developed anodized surfaces, Xeal and TiUltra, you will see a distinctive golden hue.

This coloration has not been created simply for appearance. The gold is a by-product of our advancements in applying this technology, in order to create different characteristics for different tissue integration – from soft tissue, to cortical bone, to cancellous bone.  Anodization can take titanium through an entire spectrum of color, depending on the surface characteristics it creates.

 

What is anodization?

Anodization is an electrochemical process used to engineer a titanium surface.

While titanium provides high-strength and cell adhesion, it’s the oxide layer – instantly created when titanium is exposed to the air – that makes tissue attachment possible.4 While subtractive surface technology (such as sandblasting and/or acid etching) removes material to create the roughness, anodization does the opposite – it increases the thickness of the oxide layer.

And it’s this change of thickness that causes the change of color. The basic process is this: We place the implant in an electrolyte fluid, making it the anode when we apply an electric voltage. As the voltage intensifies, and the length of time increases, the oxide layer expands to a thickness of up to 10,000 nm.5 The oxide’s changing thickness tailors interference of light at the surface, and the thicker it becomes, the more its color moves along the spectrum.

If a critical voltage is reached, sparks appear (spark anodization) and the oxide begins to break down, creating even more roughness with volcano-shaped nodules.6 The color then returns to grey, but with a matt finish. 

Why the golden hue?

Our surface treatment of Xeal abutments and TiUltra implant collars has not been tailored simply for appearance.  Nonetheless, the color at abutment and implant collar level could potentially bring its own benefits: Studies have shown that improved soft-tissue appearance can be achieved by changing the abutment color from gray to yellow or pink.7 8 9 10

 

Figure 1: Xeal abutments and TiUltra implant collars have a golden hue, not for appearance, but as a result of specific anodization processes developed to optimize tissue integration at every level. Images courtesy of Dr Giacomo Fabbri

But in essence, the golden hue is a consequence of the time and voltage needed to create a surface topography and surface chemistry specifically designed to optimize tissue attachment at a collar and abutment level.

At abutment level, studies have shown that:

  • An oxidized, nanostructured surface stimulates more gingival-fibroblast adhesion than machined.11 12
  • An oxidized surface enables more epithelial-cell attachment than a machined surface.13 14
  • Reduced surface roughness at the abutment can decrease plaque accumulation.15 16 17

At implant collar level, it is important to minimize marginal bone loss.18 Turned surfaces with just a slight roughness have demonstrated this after over 10 years of function19; and minimal to moderate roughness can reduce marginal bone loss compared to smooth surfaces.20 21

Built on evidence demonstrating the benefits of a smooth, anodized, nanostructured abutment and a minimally rough, anodized, nanostructured implant collar, our applied anodization has been fine-tuned even further. The result? As well as a desired topography and surface chemistry, it’s a surface with a golden hue.

Fine-tuning anodization – it’s more than roughness

Nobel Biocare has two decades’ expertise in applying anodization technology. After the original transition from machined to anodized implants, the impact on early failure rates was truly remarkable; from 11.4% to just 2.1% in the maxilla*.22 When it comes to long-term survival, the anodized surface showed a significantly higher survival rate than surfaces used by other brands for ten years or longer.23  Our further steps forward today go beyond just roughness, but chemistry, ultra-hydrophilicity and protection of the surface too.

Discover more about the science behind Xeal and TiUltra

*Average failure rate of machined implants 1986–2002, compared to anodized TiUnite implants 2003–2011

More to explore

References

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Posted by Chris Kendall