Zirconium dioxide is a material which was discovered in the year 1789 by the German chemist M. H. Klaproth. But it has not been until a few decades ago that it has been introduced into the world of dentistry. It became a very attractive material because of its aesthetic characteristics and its resistance comparable to that of metals.
Titanium and its alloys are currently used as a material for the manufacture of dental implants. Due to its potential aesthetic and immunologic commitment, new alternatives are being developed that must meet the same characteristics as the titanium implant. Zirconium is a material that seems to be very suitable as an alternative because it has a very similar colour to the tooth, has good mechanical properties, is very biocompatible and has little affinity for the dental plaque.
Zirconium implants’ characteristics
Zirconium implants have the potential to become the alternative to titanium implants. They are not yet widely used because of the scarcity of scientific evidence that exists in comparison to titanium implants.
Zirconium has properties superior to those of titanium as a greater resistance to compression and traction and a modulus of greater elasticity. Zirconium dioxide has been progressively modified over time to improve its properties. It is currently combined with small amounts of other materials such as aluminum oxide that make it a suitable material for use in the dental field.
Dental zirconium-dioxide implants have been available on the market since the year 2004. It demonstrated its high biocompatibility and its ability to integrate through a series of clinical and animal studies. These implants are currently placed in the esthetic sector, especially in those cases with a fine gum. They are used as an alternative to the use of titanium implants in any position of the mouth and in those patients who have allergies or will not carry metals in their body. They are contraindicated in patients who have a lack of compliance with post-operative instructions. And of course, a clinical and technical knowledge is necessary on the part of the operator on implant surgery and prosthetic restorations.
One-piece implants
The first zirconium implants were one-piece implants due to concerns about the physical properties of the macroscopic structure, or risk to fracture. However, from a surgical and prosthetic point of view, the separation of the implant body and the abutment placed on top is preferable.
Currently, Straumann, the world’s leading implant, has presented its two-piece system that aspires to achieve very good results. Innovation and technological advances lead us towards an improvement in the safety and resistance of the zirconium implants, allowing the emergence of new designs of connections and reconstructions. More clinical studies are needed, in progress, to identify all relevant technical and biological factors affecting implant success and patient satisfaction.
One-piece Implants (former PURE Straumann) present some limitations. Surgical placement of the implant is not always in accordance with the prosthetic requirement and the angled abutments to correct the inclination are not available. Cementation is the only method for connecting the tooth to the one-piece implant. While the fact that there is an absence of gap or space due to the lack of the abutment connection with the implant may seem beneficial, the difficulty in placing the implant vertically can be compromised. In the esthetic sector, the margin of prosthetic restoration is usually left below the gum and the cement used to cement the prosthesis may cause inflammation on soft tissues.
Straumann ® has brought to market the new implant PureCeramic implants. This implant is a two-piece implant with a novel system to connect the abutment to the implant. So far, two-piece zirconium dioxide implants have been connected with dual resinous cements or by adhesion of a fiberglass pillar to the implant. The Pure Ceramic Implant system offers an internal connection system equipped with a rotational lock and an inner thread for fixing the provisional components and the definitive pillars. The indications of this new implant are the following: indications of intraosseous Dental implants in maxilla and mandible and functional and esthetic rehabilitations of patients complete or partially edentulous; that is to say all the situations.
This implant features a unique ceramic surface, ZLA ®, with an ideal roughness comparable to Straumann ® SLA that presents a balance between implant resistance and osteointegration capacity. The Pure Ceramic implant is designed and produced to mitigate the risks of fracture and instability. They undergo strict production control processes to ensure exceptional levels of quality. Each implant must exceed a mechanical strength quality test of 360 º before being packaged and distributed.
