BRB Matrix for Class IV Restoration

A clinical case by our Community member Dr. Mohammed Shaga

This article and its content are published under the Author’s responsibility as an expression of the Author’s own ideas and practice. Styleitaliano denies any responsibility about the visual and written content of this work.

When restoring smiles, esthetics should follow the concepts of facially generated treatment planning, such as the incisal edge display with lips at rest, lower lip line, and so on. In most cases, the composite resin is layered using a polyvinyl silicone (PVS) palatal stent fabricated from a wax-up. Layering from palatal to buccal allows accurate control over the procedure, and reduces the need for significant post-op occlusal adjustments. Although the wax-up based stent is the most traditional approach when it comes to fabricating an index, there are different techniques, e.g. intraoral mock-up, finger index, etc. that allow us to achieve a palatal anatomy to start layering a class IV restoration. One of the techniques to obtain an immediate, chair-side-fabricated palatal stent, is the Bertholdo Ricci Barrotte (BRB) matrix.
In this article, we will show the BRB matrix technique a simple way to produce the lingual matrix without laboratory steps needed.
The BRB Matrix is fabricated from an impression taken in the patient’s mouth using a polyvinyl silicone on the palatal surface of the anterior teeth. Then the silicone is cut to modify the impression and create the palatal anatomy of the restoration, thus creating a fairly precise palatal index.

styleitaliano style italiano broken upper central incisor

A female patient, 23 years old, sought care at the dental clinic with fractures of the right maxillary central incisor. The patient had no clinical symptoms during this period.

styleitaliano style italiano class IV cavity before preparation

Intraoral pre-operative View.

styleitaliano style italiano button try for composite shade selection

Tooth shade selection by button try technique.

styleitaliano style italiano palatal silicone impression

Polyvinyl silicone material was used to take an impression for the palatal surface of teeth and covered the incisal angles firstly, then the silicone cut to be extend just below the gingival margin on the lingual aspect of the teeth and should cover at least one tooth on either side of the tooth to be restored to provide a solid seat.

styleitaliano style italiano marked incisal extension and length on silicone index

The resulting silicone index was drawn with a marker to simulate the amount of tooth structure lost due to the accident. At this stage, two details in particular require the most attentive care, the distal lines and the position of the incisal edge

styleitaliano style italiano carbide bur trimming silicone index

A carbide bur was used to remove the necessary amount of silicone until the correct palatal shape was obtained and the trimming is performed carefully not touching beyond the cavo-surface palatal margin.

styleitaliano style italiano trimmed silicone stent

All of the internal excess was trimmed with the bur until the desired anatomy was obtained.

styleitaliano style italiano try in of modified silicone index

A try in of the silicone index was done to ensure correct adaptation and to check the designed palatal shape.

styleitaliano style italiano beveled and rounded class IV cavity margin

Beveling and rounding of the sharp edges were obtained by flame diamond bur and finished with abrasive discs.

styleitaliano style italiano try in of brb matrix on prepared class IV cavity

Finished BRB Matrix. Finally, the restoration can be performed, after rubber dam isolation, by following the selected layering technique. All the following steps are explained in detail by previously published articles (4, 5).

styleitaliano style italiano surface texture check with articulating paper

After complete composite layering, articulating paper was rubbed on the surface of the adjacent tooth to highlight the features to recreate during the finishing procedures.

styleitaliano style italiano carbide bur texturizing composite restoration

A straight carbide bur was used to achieve V shaped grooves on labial surface of the restoration.

styleitaliano style italiano final check of surface texture of composite restoration

The articulating paper was once again used to check the degree of resemblance in the anatomy of the restored and the natural tooth.

styleitaliano style italiano brush polishing composite

A bristle brush was used to apply the polishing paste on the surface to achieve a glossy appearance.

styleitaliano style italiano felt brush polishing composite class IV restoration

A felt brush was then used to increase luster without scratching the surface of the composite resin.

styleitaliano style italiano composite class IV restoration

Intraoral post-operative view.

styleitaliano style italiano smile after restoration of broken tooth

Extraoral post-operative view.

styleitaliano style italiano brb matrix restoration final result surface texture


Surface texture.


The BRB Matrix technique is one viable method that offers a simple and fast method to treat fractured incisors without waiting for a wax-up, thus often becoming easier, more convenient and time efficient while allowing the clinician to keep control of the esthetic and biological results.


1. Jason Smithson. Planning the Class IV: The Workhorse of Cosmetic Dentistry — Part 1. 2021
2. Caroline Werkhoven. How to make a silicone index that works for you.2016
3. Denehy GE. Simplifying the class IV Ligual Matrix. Journal of Esthetic and Restorative Dentistry. 2005; 17: 312-9.
4. Shaga M. Class IV Restorations in StyleItaliano Philosophy. 2021
5. Shaga M. 3D Palatal Index for Class IV Composite Restoration. 2022
6. BRB Matrix. 2014

style italiano styleitaliano Essential Dentistry kit online on demand course
style italiano styleitaliano Essential Dentistry kit online on demand course


styleitaliano style italiano smile proximal composite restoration technique cavity design polishing proximal walls

Proximal composite restoration from cavity design to polishing

How to create stunning direct posterior composites, from cavity design to polishing, with exceptional proximal composite restoration technique.
styleitaliano style italiano proximal caries cover image snowplow technique direct posterior restoration bulk composite Kerr SimpliShade Bulk Fill composite restoration

Bulk flow for Snowplow