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.