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.

incisors with old class 4 composite restorations

Initial situation. The chief complaint was about the unsatisfactory class IV restorations on both central incisors.

rough too bright composite fillings on incisors

Close-up of the old composite restorations.

weirdly shaped lateral incisors

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.

wax up on cast model for central incisors

A wax-up was done on the model to fabricate the silicone key.

polarized picture for color selection of composite resin

A polarised picture was taken to plan the layering.

rubber dam isolation of anterior sextant

Field was isolated with the rubber dam.

prepared class IV cavities on central incisors

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.

palatal view of class 4 cavity preparation

After sandblasting with Al2O3, the palatal surfaces are also clean now.

silicone index sit for palatal wall restoration

Try-in of the silicone index.

etchant on enamel for enamel conditioning and adhesion

Etching for 30 seconds with phosphoric acid.

bonded cavities for direct composite filling

After applying the adhesive layer.

palatal composite walls on central incisors

A thin palatal wall was created with the help of the silicone index.

unica matrices for incisor composite restoration

Positioning of both Unica matrices at the same time. The palatal shell is stabilizing the matrices, and a convex approximal surface can be easily created.

occlusal view of the unica matrices

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.

layering proximal wall using the unica matrix

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.

Proximal walls built with composite resin

Palatal and approximal walls are now finished. Now the base is solid to start layering.

layering of dentin mass and shaping mamelons

Layering the dentin mass while shaping the incisal third.

opalescent mass layered in the incisal third

An opalescent flowable material is placed in the incisal third to add some depth.

composite restorations on incisors before finishing

And then the enamel composite mass was layered.

glycerine gel air-block for composite polymerization

Final curing should happen under a layer of glycerine gel to get better polymerization.

shaped but rough reconstructed incisors

After final light curing. We should create the shape mainly with the final layer.

drawing angle lines and texture on composite

During the polishing, my goal is to create perfect symmetry and proportions, and a texture similar to that of the neighbouring teeth.

finished seamless composite restorations on centra incisors

Before the removal of the rubber dam.

composite restoration of central incisors before rehydration

Final result after removal of the rubber dam.

composite incisors after rehydration

The aspect of the restorations after rehydration.

smile with invisible restored incisors

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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2. Vanini L. Mangani F. Klimovskaia O. Conservative Restoration of Anterior Teeth. Acme, 2005

3. Villarroel M, Fahl N, De Sousa AM, De Oliveira OB Jr. Direct esthetic restorations based on translucency and opacity of composite resins. J Esthet Restor Dent. 2011 Apr;23(2):73-87

4. Vichi A. et al. Influence of thickness on color in multi-layering technique. Dent. Mater. 2007 Dec 23 (12);1584-9.

5. Influence of enamel composite thickness on value, chroma and translucency of a high and a nonhigh refractive index resin composite. Ferraris F, Diamantopoulou S, Acunzo R, Alcidi R. Int J Esthet Dent. 2014 Autumn;9(3):382-401.


Biologically Guided Simplified Anterior Restoration

A simplified layering technique with only two composite opacities can solve most of our anterior restorations, if we respect the biology and the shape of the restoration.