Dental Asia Jan/Feb 2019

Behind the Scenes DENTAL ASIA JANUARY / FEBRUARY 2019 56 By DMT Karl-Heinz Körholz Digital set-up Setting up continues with the wizard step “Denture tooth placement”. The best fitting posterior teeth are automatically selected from the sets of teeth saved in the library. First, the various tooth shapes and sizes are displayed, which, according to the values determined in the model analysis, come into question in this case. Coloured data in green letters confirm that these tooth shapes fit best in terms of size, while those in red letters are not quite as suitable in terms of their dimensions, but could still be selected if desired. is the first premolar. The occlusal plane forms the specification for the horizontal alignment of all anterior and posterior teeth. This means that it is no longer possible for “the left side to droop” provided that the occlusal plane had previously been specified correctly in the dental practice. For control purposes, the model analysis or, as shown here, the common set-up region, can be visualised at any time by showing/hiding (Fig. 2b). Part II: Logical, Feasible and Digital Can full dentures also be created digitally? “Yes,” says DMT Karl-Heinz Körholz and illustrated the analogue steps of a challenging patient case in part one. In part two, everything revolves around the digital fabrication phases with the FDS System from Amann Girrbach. Fig. 1: Wizard step “Denture tooth placement”: the tooth sets saved in the library are suggested automatically based on the results of the model analysis. First, the various tooth shapes possible according to the model analysis, are displayed. Coloured data in a green font indicate that these tooth shapes fit in terms of size, those in a red font deviate more strongly from the result of the model analysis, but can still be selected if desired. As a further option, one can select whether the second molars are set up always, never or only if possible according to the model analysis. Figs. 2a-b: The “Place Posteriors” button automatically sets the selected posterior teeth according to the model analysis. The six is in the right place, as is the first premolar. The occlusal plane acts as the specification for the horizontal positioning of the posterior teeth. Fig. 3: When setting up the anterior teeth, the technician can also view the less suitable sets of teeth to get an idea of the space available and select the optimum tooth shape and size for this patient. In the classical set-up, this could only be achieved with an enormous effort in time. Fig. 4: Harmonious and functional set-up, as recommended by the program by selecting the anterior and posterior teeth in green font. This gives the dental technician a very useful suggestion, which can also be adopted in most cases. This wizard step also offers the option of selecting whether, for example, the second molars should be set up in every case or only if this is possible or never (Fig. 1). The “Place Posteriors” button automatically sets the selected posterior teeth according to the model analysis. The six is set up in the determined position as Fig. 2a Fig. 2b When setting up the anterior teeth, the technician can also have the tooth sets displayed that do not fit perfectly (indicated in red) to get an idea of the corresponding alternative tooth shapes and space conditions. Such an approach would of course also be possible in the classic set-up with wax and a wax knife, but it would be far more elaborate. Compared to the manual technique, the digital set-up of anterior teeth offers an enormous time advantage at this point (Fig. 3). If all previously determined parameters of the model analysis as well as the tooth library are taken into account, the result will generally lead to a harmonious and functional set-up. This gives the dental technician a very useful suggestion, which can in most cases be adopted in this form (Fig. 4). The procedure of displaying the aesthetic template “over” the set-up during or after setting up the anterior and posterior teeth is extremely effective. This has the advantage that matches or deviations can be recognised directly on the screen. In the analogue working process, this can also be seen approximately by using previously fabricated silicone keys; however, this is considerably less precise,

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