Choosing the right matrix in posterior restorations

Even the most common cases in our everyday practice may hide clinical challenges. In particular, posterior proximal restorations may become tricky when the cavity is large, which makes it harder to obtain a tight contact point, at the correct height, and with an anatomical gingival and occlusal embrasures.

style italiano styleitaliano old amalgam fillings

This patient presented with defective old amalgam proximal restorations that cause food impaction and difficulty on flossing. So we decided to replace the old restoration with new, more anatomical ones.

style italiano styleitaliano prewedging during removal of old fillings

The amalgam restorations were removed under rubber dam isolation, starting with pre-wedging to protect the rubber dam (and the papilla), and to increase separation between the teeth to improve visibility and minimize sound tissue removal.

style italiano styleitaliano clean wide proximal cavities

The final cavity design had left a very wide proximal space, so we needed a contoured matrix to achieve a correct positioning and shaping of the contact area.

style italiano styleitaliano trasparendo matrices

The transparent biofit HD matrix from Bioclear was used in this case as it has a high contoured profile. Both matrices were placed at the same time to avoid over contouring of one proximal wall in the space of the adjacent tooth.

style italiano styleitaliano transparent contoured matrices

Lateral view shows the level of the contact point.

style italiano styleitaliano layering of molar cavity

After restoring the proximal wall of the molar, the first matrix was removed to avoid creating a loose contact. This type of matrix is 75 microns thick, which is considered very thick, so extra separation, using a large wedge. Moreover, the wedge was wrapped in teflon tape to achieve a tighter seal and to enhance separation ad matrix retention.

style italiano styleitaliano layering of proximal cavities

The proximal wall of the premolar was restored, then the matrix was removed. As you can see, the increased separation made the contact seem open.

style italiano styleitaliano occlusal modeling with fast modeling technique

The occlusal anatomy was restored by using FMT (Fast Modeling Technique), the composite was placed as a single mass. Fissures should be deep to reduce the C factor. P shade composite from White Dental Beauty was used in this case, which is a universal composite for the posterior teeth.

style italiano styleitaliano white dental beauty composite system
style italiano styleitaliano white dental beauty composite system
style italiano styleitaliano brown staining of sulci

After curing the composite, the fissures were sealed with a dental brown tint.

style italiano styleitaliano sandblasted composite restorations

Both fillings were sandblasted by sodium bicarbonate powder using the Aquacare device to enhance the final polish.

style italiano styleitaliano polished composite restorations

After final polishing and removal of the wedge, you can see the proximal space closed.

style italiano styleitaliano lateral view of proximal restorations

Lateral view is very useful to evaluate the level of the contact area and the proportions of the occlusal and gingival embrasures.

style italiano styleitaliano final result after proximal cavity filling

The final result.


Planning a posterior proximal restoration is a mix of space engineering selecting the right materials and tools. To achieve optimal anatomical features for long-lasting and biocompatible restorations, very step should be well planned and executed.


1. Hardan L, Sidawi L, Akhundov M, Bourgi R, Ghaleb M, Dabbagh S, Sokolowski K, Suarez C, Szymanska M. One-Year Clinical Performance of the Fast-Modelling Bulk Technique and Composite-Up Layering Technique in Class I Cavities. Polymers 2021;13:1873.
2. Manauta J, Salat A. Layers An Atlas of Composite Resin Stratification. 2012. Quintessence Pub.
3. Van Dijken JW, Pallesen U. 2016. Posterior bulk-filled resin composite restorations: a 5-year randomized controlled clinical study. J Dent. 51:29–35.
4. Ferraris F. Adhesion, layering, and finishing of resin composite restorations for class II cavity preparations. Eur J Esthet Dent. 2007 ;2(2):210-21

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


Post-orthodontic treatment with direct composite veneers

Direct composite veneers are nowadays a great instrument to achieve highly aesthetic results, with a low financial effort, and without the need for tooth preparation.