Sequential wax up
Sequential wax up according to Professor Rudolf Slavicek’s technique is a prosthetic product planning that considers all the functional guides and the dental contacts, and even the possible prosthesis abrasion over time. Actually we do the wax up in pure canine guide (according to the Vienna school of Professor Slavicek), but if this lost efficiency through the wear of time, it would come into operation the functional guide of the first premolar and so on until we arrive to affect the whole quadrant reaching a group function, but always respecting the prosthetic work function.
Before we start the sequential wax up we need to set individual values for the articulator through an axiographic test. We need to establish the correct vertical size with values achieved through the cephalometric tracing, a correct occlusal plane and a correct operating articular position, using RP waxes. At this point we assemble the model on articulator with the help of a preferably kinematic face-bow.
How to realise the models
We have to arrange the upper model with split-cast.
We have to arrange the lower model with removable dies for each tooth, except the group of the four lower frontal teeth; During the wax up, we need to remove some elements so that we can check the right sequentiality and the functional path of each waxed element.
EXAMPLE OF CORRECT REALISATION OF THE LOWER MODEL WITH REMOVABLE ELEMENTS (slider).
After having accurately arranged the model and assembled it on articulator, we can start to realise the sequential wax up.
Wax up in skeletal class I
The first step is to wax the cones of the lower active centric line and of the upper passive centric line so that they correspond to each other (See: active and passive centric arch).
The lower cones correspond to molar and premolar buccal cusps, to the canines tips and to the incisal edges of the frontal teeth. The upper cones correspond to the central fossa of the first molars and to the marginal edges of molars, premolars, canines and incisors.