From wax-up to mock-up to no-prep veneer – efficient technique for a successful patient consultation
It is the wish of patients to have greatly improved anterior aesthetics without having to undergo time-consuming, painful and expensive orthodontic treatment. In this article we will discuss how you can provide this service using a highly efficient technique.
The trick with the two models
The dentist simply takes an alginate impression of the patient’s upper and lower jaw at the initial consultation. The dental technician pours these impressions twice in the lab. The first time using snow-white dental stone and the second time using brown dental stone.
The brown stone model remains unused and represents the actual situation of the patient’s dentition. The dental technician fabricates a wax-up on the white stone model using “GEO Snow-white opaque” wax. To ensure that the important optical effect is not put at risk by carbon residue, it is best that the dental technician uses an electric wax knife such as the Waxlectric. The wax-up represents the ideal shape of the planned new anterior teeth of the patient. The dental technician fabricates a silicone mould of this ideal shape and a preparation aid for the dentist.
At the next appointment in the dental practice (next day if possible), the dentist shows the patient the existing, suboptimal dentition using the brown stone model. The dentist then advises the patient using the attractive white stone model with the equally white wax about the kind of aesthetics and symmetry the patient could have instead. Patients find this type of consultation highly illustrative and would like to have the same nice teeth as quickly as possible.
A step further in the consultation
In order not to overexert the abstract ability of the patient, the dentist uses the silicone mould of the wax-up, fills it with white composite and places the silicone mould on the patient’s anterior teeth. The mock-up is now another consultation tool for the dentist and the patient can see the planned new teeth directly in the mouth and is in a better position to decide for or against the restoration. Depending on the stability of the mock-up, patients can also wear the mock-up for one day at home to show it to their partner or friends, if they cannot make an instant decision in the practice.
With this type of consultation experience has shown that in the majority of cases involving the aesthetic try-in of the mock-up the decision is instantly made in favour of the new teeth.
Fabrication of the restoration
The dentist then uses the silicone mould of the wax-up again to determine whether and where the teeth have to be prepared minimally. Next the dentist takes a precision impression of the anterior teeth using the same technique and material as for any standard crown or bridge.
The dental technician then fabricates a standard sectioned model in the laboratory. To transfer the wax-up pattern efficiently and reliably to the new sectioned model, the dental technician uses either a wax injector or flows sculpting wax into the silicone mould using an electric wax knife and the large wax knife and then presses this on the sectioned model.
The wax injector is very efficient: the dental technician drills two holes in the silicone mould. One is used for injecting the wax into the mould and the other is to allow the air to escape. The silicone mould is then removed and the shape and precision of the wax pattern is optimised. A wax that burns out without residue must be used for this, which should ideally be applied with the large electric wax knife to avoid burnout residue, as this would impair the quality of the pressable ceramic.
After the dental technician has finally compared this wax pattern with the wax-up of the aesthetic try-in, the wax veneer is sprued, invested and pressed, preferably in a lithium disilicate ceramic. The dental technician can now use the time-saving staining technique, i.e. select the shade of the press blank so that it does not require additional porcelain build-up and only staining and glazing porcelains have to be used. Or, if special requirements have to be made for the aesthetics and interplay of shades, the veneers are trimmed back to the dentine core and this is overlaid with effect, enamel and/ or shade modifier porcelains. The dental technician completes a final glaze firing cycle and mechanically polishes the veneers to the required degree of glaze, which can be significantly influenced by mechanical polishing.
The veneers can be fabricated with exceptionally thin wall dimensions using this technique and the material selection described. So thin that they sometimes look like colourless, transparent glass.
Patients have the feeling that they have actually received what was promised at the aesthetic try-in! Dentist and dental technician are soon regarded as heroes of aesthetic dentistry.
Finally, it should be noted how quick it is to work with this technique. Four upper anterior teeth veneers can be finished and cemented within four days. There is minimum risk during fabrication. And if an error or failure should occur during fabrication, it can be quickly remedied without major investment, apart from the time lost. There is a rapid cash flow for the practice and lab.
This consultation can be the beginning of a good customer relationship with the patient. With the confidence gained the patient is happy to become integrated into a treatment concept. Professional tooth cleaning and polishing or renewal of old, unaesthetic fillings through to bleaching can represent a competent overall concept. Once the target or final shade is achieved, the veneers can be fabricated as described above.