Preoperative occlusal matrix aids the development of occlusal contour of posterior occlusal resin composite restorations--clinical rationale and technique

Aesthetic restoration of posterior teeth using different occlusal matrix techniques

The occlusal matrix technique appears as an alternative to the conventional restorative technique. The aim of this study is to present treatment options for the decayed occlusal surface of posterior teeth by means of an occlusal matrix made with different materials, for an accurate reproduction of the tooth surface. This paper presents five clinical cases using five different materials, such as Bite-Perf, flowable composite, self-curing acrylic resin, silicone and thermoforming foil. Before light-curing, the last layer of composite resin, the matrix, is repositioned and firmly pressed so the replication of the original occlusal anatomy can be achieved. When using an occlusal matrix, minimal or no finishing and polishing procedures are needed and the offered aesthetics are clearly an advantage. Moreover, this technique makes up for the additional chairside work time. The occlusal matrix technique is demonstrated to be effective for direct composite resin restorations in posterior teeth, allowing a reliable and predictable reproduction of the occlusal anatomy and clinical adjustment. For this purpose, a clear material is preferable since it allows light transmission.

A quantitative assessment of silicone and PTFE-based stamp techniques for restoring occlusal anatomy using resin-based composites

OBJECTIVES

Publications on stamp techniques for placing resin-based composite (RBC) restorations consist mainly of case studies. Furthermore, comparative studies are rare and no longer relevant to the materials tested today. Thus, two general techniques were investigated in this study.

MATERIALS AND METHODS

Standardized occlusion class I cavities were prepared in twenty-eight extracted caries-free wisdom teeth with unimpaired occlusal surfaces and restored with the RBC material Grandio^®. Light curing of the final layer was performed either after removal of the stamp isolated with PTFE tape or by leaving a stamp made of transparent polysiloxane in place. CEREC scans of the RBC restorations placed (follow-up) were superimposed on scans of the unimpaired occlusal surface (baseline) and quantitatively analyzed with the software OraCheck with regard to volume change and gain or loss of layer thickness in six sectional planes.

RESULTS

Assessing the excess material, there was no difference (p = 0.31) between the silicone technique (0.26 mm ± 0.02) and the PTFE technique (0.22 mm ± 0.02 mm). Nevertheless, the loss of tooth substance was significantly greater (p < 0.001) with the silicone technique (-0.29 mm ± 0.02 mm) than with the PTFE technique (-0.15 mm ± 0.02 mm).

CONCLUSIONS

With the PTFE stamp technique, less healthy tooth structure was removed during the finishing procedure and the stamp was more dimensionally stable.

CLINICAL RELEVANCE

The study shows the advantages and disadvantages of the investigated stamp techniques and helps the practitioner to choose an appropriate technique.