Compared to the use of fixed partial dentures (FPDs) implants are the more physiological solution for the management of cases with missing teeth. There is no damaging of other teeth for using them as pillars and the alveolar bone can be preserved. Also, the esthetic outcome using high-developed implant solutions is much better than with FPDs.
But of course, there are some disadvantages in the use of implants. The process is much more invasive due to the surgical intervention. This is depending on the amount and quality of the bone and there is a need for a healing period. The correct placement of implants is a job for specialists and needs a good planning.
To achieve good esthetical results a soft-tissue management is necessary. Also, the design of the superstructures needs special knowledge and experience. A computer-aided process is because of the complexity of the whole process today state of the art for those kinds of treatments. It starts with the planning. On the basis of 3D x-ray data, the best possible implant position can be determined with the help of planning and navigation software. Additionally, already in this stage, the later form of the restoration can be considered when doing the x-ray in addition with a radio-opaque scanning template or combining 3D x-ray data with 3d CAD/CAM data (Cerec meets Galileos, Sirona, Germany).
The process is known under the name backward-planning and starts with the later form of the final restoration. On the basis of the proper planning, a drilling template makes the implantation process safer and faster. Guided surgery is today supported by the most of the implant systems. After the surgical step, the position of the implant can be determined very easy with an intraoral, three-dimensional scanning using a scan-body fixed on the structure and an intraoral 3D scanning camera. In addition to the determination of the implant position also the form of the soft tissues can be captured. On the basis of these data provisional restorations as well as the final superstructures can be created with the help of dental CAD/CAM systems. For the final restoration pre-fabricated abutments can be used as well as the can be individually produced. Because of the big variety of possible cases, individual solutions should be the preferred way.
Abutments can be made either from metal or ceramics. At the moment the combination of both (hybrid-abutments) seems to be the best solution. So the high strength and precision of a metal-connector can be combined with the good esthetical properties of ceramic materials. One good and effective way of design and production of these hybrid-abutments is the use of the Ti-base connector (Sirona, Germany). On one side the connector is available for a lot of different implant systems and on the other side, it has ever the same interface for the connection with a ceramic block. Those ceramic parts were made at first from zirconium dioxide (InCoris meso, Sirona, Germany).
Those blocks already have the pre-fabricated hole for the intake of the connector interface inside. So an absolutely perfect fit is guaranteed. Because of the lack of esthetic of the zirconium material those blocks can be used for pure abutments with and additionally made covering crown or to mill a crown in a reduced form for later veneering. A new possibility is now the use of lithium disilicate in the same way as the zirconium dioxide (e.max abutment solutions, Ivoclar Vivadent, Schaan). Besides of the standard abutment with a covering crown here exists the possibility to create a so-called hybrid abutment crown. The basis for this is the very good esthetic outcome of the full contour and only stained and glazed lithium disilicate ceramic. Those crowns are simply to produce, have a lot designing possibilities because they are only consisting of two parts and they have a very good, tooth-like appearance.
