Gold-Standard for Implant Superstructures Special Edition

Comparisons, like allegories, result in different things being compared to each other leading to new approaches. Even the "micro-cosmos dental technology" does not remain untouched. The signs of the time point towards metal-free restorations. Does dental technology lose its old operating system, i.e. the precious metal technique? In dentistry, gold in many variations is a material that has been used for more than a hundred years. Gold alloys have been clinically investigated again and again since that time and always scored outstanding results with regard to compatibility and durability. That...

The processing of mixed materials known as "precious metal alloys" is very complex and directly depends on the technical indication. Well-founded knowledge of all the disciplines of material processing is further promoted by a pronounced willingness and enthusiasm to learn new things and implement them accordingly. The complex processing steps have to be supported by a high performance level as far as the casting technique is concerned. The precision is confirmed by the excellent accuracy of fit of all framework indications without having to sacrifice the creative design of the framework. This...

Model situation Model fabrication The basis of each working procedure in the dental laboratory is an outstanding and reliable base or master model. For the fabrication of this implant-retained restoration, the model analogs (RN synOcta Gold coping) are used in conjunction with plastic modelling aids. The situation on the stone model exactly represents the implant position in the oral cavity. The transfer of the model analogs is achieved with the help of what is known as passive splinting. This is already a significant aspect in the examination and discussion of the dimensional stability of impressions....

Primary structure Contouring Adjustments are added on the implants using a wax-up. The oral situation can be transferred to resin that fires without leaving residue by means of a silicone key. What is known as the rough body is finished and repositioned on the model. It is fundamental that the planning also takes the natural tooth extension into consideration. Interferences to phonetics due to severe over-contouring possibly caused by unfavourable implant positions also have to be taken into account. Optimum hygiene capability is also related to this aspect. Sound working procedures considerably...

The framework is designed by controlled reduction of the wax-up. The clean silicone matrix permits quick and reliable orientation. Each surface requires two silicone keys. While the first matrix reproduces the entire surface from cervical to incisal, the second matrix is bisected horizontally. In this way, the labial-palatal surfaces can be checked from the occlusal. The mesostructure must provide sufficient space for the secondary framework and also predetermine the statically relevant separation spaces, as well as the cervical parts of the tooth shapes. The final step in designing the mesostructure...

Sprueing / Investing Tension-free accuracy of fit of the wax-up can only be achieved if the sprues are waxed-up independently of the framework. When attaching the sprues to the framework, the free access to the prosthetic screw must be checked and ensured. The framework remains secured by means of the prosthetic screws until is has been completed and the sprues have been attached. The wax-up is completed with an even and clean coat of wax. Usually, the highest tensile stress occurs in the area of the interlocks. Bilateral cooling grids attached as symmetrical as possible ensure quick and even...

Casting / Finishing The use of resin that fires without leaving residue additionally requires that holding times are observed during the heating of the casting object. The Academy Gold XH alloy is cast in the vacuum-pressure technique observing the casting parameters to obtain a homogeneous cast. In order to achieve optimum accuracy of fit, the investment material in the area of the gold coping capable of being cast on must not be removed by means of blasting media (Al2O3). Investment material residue must be removed by means of acid treatment.

The targeted placement of the cooling grids enables homogeneous casting results (Academy Gold XH), particularly in the transition areas to the inner aspects of the copings. Upon injection of the alloy, a desired loss of energy occurs, which results in quick solidification of the alloy, also known as germination. The cooling grids ensure that no impact pressure occurs in the shoulder area during the casting procedure. It is very likely that this also prevents frequent overshooting of the HSL copings by the melt. With precise planning and execution, the desired framework structure is created in...

Secondary structure Contouring The mesostructure is the primary interlock between the individual implants. An exactly designed primary structure results in an even secondary framework. This also significantly supports the joining of the two framework structures. A high-quality restoration is characterized by its details. Before contouring, the transverse screw is entirely screwed in and carefully sheathed with modelling resin. Drilling a screw connecting through the primary and secondary framework does not result in the desired cold welding and thus the required strength.

A stable framework made of modelling resin that fires without leaving residue is applied on the milling surfaces. After one hour, the framework can be removed and evenly finished. The grinding instruments must demonstrate ample sharpness, since no high grinding resistance should occur. Thermoplastic deformation during finishing often prevents sound accuracy of fit. However, the nevertheless intensive mechanical stress during finishing of the new structure requires targeted adjustment of the entire marginal area. The completed resin framework is anatomically supplemented with wax. In order to...