Creating natural shapes with contemporary tools. The Unica matrix.
During the restoration of Class IV cavities, the step of creating palatal and approximal walls of the restoration is crucial, as it can help either misguide the thickness of the following layers. Therefore it is worth the investment of time to pay attention to details at this stage. This article will give a guide to the management of these steps with the Unica matrix.
Initial situation. The chief complaint was about the unsatisfactory class IV restorations on both central incisors.
Close-up of the old composite restorations.
At this moment it is important to understand the patient’s expectations. In this case, she was not bothered by the slightly irregular shape of her lateral incisors.
A wax-up was done on the model to fabricate the silicone key.
A polarised picture was taken to plan the layering.
Field was isolated with the rubber dam.
The old restorations were removed and a bevel of 1.5 mm length and 1mm width was created on the buccal edge. The preparations were also sandblasted using Al2O3.
After sandblasting with Al2O3, the palatal surfaces are also clean now.
Try-in of the silicone index.
Etching for 30 seconds with phosphoric acid.
After applying the adhesive layer.
A thin palatal wall was created with the help of the silicone index.
The position of the matrix from palatal to buccal is, in this case crucial on the mesial, while it’s not as important on the distal.
Creating the approximal enamel walls. This layer should be thin and brought to an appropriate height in order not to mislead us in the following steps.
Palatal and approximal walls are now finished. Now the base is solid to start layering.
Layering the dentin mass while shaping the incisal third.
An opalescent flowable material is placed in the incisal third to add some depth.
And then the enamel composite mass was layered.
Final curing should happen under a layer of glycerine gel to get better polymerization.
After final light curing. We should create the shape mainly with the final layer.
During the polishing, my goal is to create perfect symmetry and proportions, and a texture similar to that of the neighbouring teeth.
Before the removal of the rubber dam.
Final result after removal of the rubber dam.
The aspect of the restorations after rehydration.
Final smile of the satisfied patient.
This case shows the importance of accurate treatment planning and communication with the patient. A simplified protocol can help create natural looking restorations, together with modern materials and instruments that make our life easier during the process. The key aspects are layer thickness, shape and outline of the restoration. With proper handling of the silicone key and special matrices it is predictable to create palatal and approximal outline of the restoration, and the control of layer thickness is greatly supported as well.
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