Ceramic implants are nothing new – so why are zirconium implants offered now?

The demands of patients for highly aesthetic restorations have increased tremendously during the past few years so that they are not willing to accept the dark shade of titanium implants in the soft tissue (gingiva). whiteSKY meets the demands of patients and allows to fabricate aesthetically appealing dental restorations.

These increased demands in the field of aesthetics can also be observed in the sector of conventional prosthetic restorations in which the zirconium material is about to replace metal bridges.

Another major advantage of the zirconium material is its biocompatibility. A growing number of patients have developed allergies to metals; zirconium implants represent an alternative for this group of patients.

How does the whiteSKY implant differ from the Tübingen implant?

The main difference lies in the primary stability of the implant. Owing to the lacunae, the Tübingen implant had highly reduced primary bone contact; the result was that a very high loss rate was observed during the healing phase. Moreover the material revealed insufficiencies which resulted in an increased tendency to fracture after 10 years. whiteSKY features a modern implant design with a surgical protocol matched with the respective bone quality. This protocol ensures that primary stability is guaranteed by bone compression. Thanks to its elasticity and mechanical properties, zirconium is less susceptible to fracture than aluminium oxide used for the Tübingen implant.

Aluminium oxide implants were highly susceptible to fracture? What is the fracture behaviour of zirconium?

The tendency to fracture of aluminium oxide implants was observed in the 70s – especially for the Tübingen implants. The results of this observation can be attributed to two factors; on the one hand, aluminium oxide is a relatively brittle material and tends to break easily; on the other hand the prosthetic concept which included cemented metal pins even led to an increase in the tendency to fracture.  
The zirconium material is much more elastic than aluminium oxide and hence less susceptible to fracture; moreover, all measurements that were performed showed that the risk factor of fracture could be eliminated thanks to the one-piece design of the whiteSKY implant. 

Why is zirconium a suitable material for implants?

If you consider all mechanical properties, zirconium is the perfect material for dental implants. The flexural strength of zirconium is three times above that of titanium and two times above that of aluminium oxide and the modulus of elasticity is between those for titanium and aluminium oxide; i.e. it has a higher dimensional stability than titanium and is less susceptible to fracture than aluminium oxide. Additionally, zirconium features a "defect blocking property" to avoid the expansion of microfractures. Consequently, excellent long-term primary stability is ensured and good results can be achieved in the field of dental implantology.

Osseointegrated zirconium?

A series of animal experiments showed that firm osseointegration can be achieved with zirconium. In this context the surface of the implants is highly relevant. Studies with the brezirkon material that is used for whiteSKY showed that comparable results of bone apposition were achieved for comparable surfaces of a titanium implant and our zirconium implant.  As far as surface treatment is concerned, we continue the development of brezirkon under scientific guidance to achieve optimal results.

Are zirconium implants going to replace titanium implants?

Over the long term zirconium will certainly reach a high market share since there is a growing demand for these implants for certain indications among dentists and patients as well because of the advantages of the material (colour, biocompatibility). However, we do not believe that – over the medium term – zirconium implants will entirely replace titanium implants but that both systems will be used for specific indications.

Can zirconium implant be recommended for all indications?

The critical phase of the single component zirconium implant is the first few weeks after implant placement (during the healing phase). It is necessary to protect the implants against excessive stress (loading) during this period. Therefore we recommend to use whiteSKY implants only for single tooth replacement or small gaps in the dentition; efficient protection can be easily provided for these indications. In cases of gaps in the dentition, each lost tooth should be replaced with one implant. Currently, zirconium implants should not be used for free-end situations and edentulous ridges.

What type of restorations should be used for zirconium implants during the healing phase?

Generally, two different tendencies can be observed among our users and also in the scientific literature. Some users attempt to protect the zirconium implants through the use of splints to avoid any exposure to stress during the first few weeks; others try to protect the implant against excessive stress by applying the rules of immediate loading.

What are the risks involved when using splints for protection?

When using splints to protect implants it is important to make sure that the patient wears the splints permanently, i.e. during day and night time since the implant needs to be protected against excessive tongue and cheek pressure. Frequently, however, splints do not offer sufficient comfort of wearing; as a result the patient does not wear them permanently contrary to the dentist's advice. In such cases there is a risk that only soft-tissue integration will occur. In a very limited number of cases this could be determined only after the insertion of the definitive restoration which caused noticeable increase in the economic damage.
Therefore we recommend to first place a resin crown onto the implant – following splint therapy over six to eight weeks – and thus continuously increase the stress (load) on the implant.

Can prosthetic restorations immediately be placed/attached on/to the implant after the insertion?

Basically, yes. However, it must be ensured that crowns and bridges that are immediately luted on implants must have a considerably smaller volume than natural teeth and designed in a way to offer a large contact area/surface with adjacent teeth so that these teeth are able to protect the implants and the temporary restoration. Additionally, Ribbond fibres can be used to connect the restoration to the adjacent teeth.

What is the current situation in the sector of zirconium implants from the view of bredent medical?

Is bredent medical also going to offer two-piece zirconium implants in the future?

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