Direct Composite Veneers: Overview of different matrix systems

Objectives: The vast variety of matrix systems currently available in the market, provide dental practitioners with the opportunity to select the best fitting method according to their personal preference and skills. Nevertheless, due to lack of updated knowledge or fear of engaging into new techniques, dentists often struggle to incorporate new approaches in their practice, since they are unfamiliarized with either their effectiveness, or means of utilization. The aim of this study is to comparatively evaluate 4 of the most widely used matrix systems: the modified putty index matrix technique with mylar strip, the Unica and Bioclear matrix systems, and the Injection Moulding Technique with silicone key.

Methods: The previously mentioned systems were compared with the digitally designed mock-up, based on the aesthetic outcome of the final restoration, the accuracy of the restored proximal surfaces with the help of a CAD program (Exocad), the duration of the procedure, ease of use of each technique and the technique sensitivity. The experiment was carried out by eight -highly skilled- 4th and 5th year dental students from the European University of Cyprus, who put to the test all 4 systems on typodonts attached to phantom head simulators.

Results: Highest restorative material divergence values in the CAD analysis: Proximal width on cervical third – Conventional and Injection Moulding (-0.836 and -0.826 mm), Contact point width – Injection Moulding and Unica (-1.279 and -1.267 mm), Cervical Labio-Palatal width – Injection Moulding (-0.878 mm), Incisal Labio-Palatal width – Bioclear (+0.821 mm). Average procedural time: Conventional 79.125 minutes, Injection Moulding 62.25 minutes, Unica 60 minutes, Bioclear 58.667 minutes.

Conclusion: The closest resemblance to the mock-up was achieved by the Injection Moulding technique, while with the Bioclear method showcased the best interproximal marginal integrity. The most time-consuming procedure was found to be the Conventional technique while the fastest was the Bioclear method. From students’ feedback, the most technique sensitive procedures were Injection Moulding and Bioclear method, while the highest “ease of use” score of 7.5/10 was acquired by Injection Moulding technique.