Cusp Deformation of Standardized Artificial Cavities by Siloranes and Methacrylates

Objectives: The goal of this study was to compare the polymerization-induced cusp deformation by a Silorane composite and conventional resin composites based on methacrylate chemistry in a tooth cavity model.

Methods: Slot-shaped cavities (8mm x 2mm x 2.5mm) were prepared in aluminium blocks (8mm x 8mm x 15mm), with the thinner cavity wall having a thickness of 2mm. Aluminium was chosen in order to eliminate the variation inherent in natural teeth, and because of its elastic modulus (70GPa) comparable to enamel. The cavities were bulk-filled with Filtek Silorane (SIL, 3M ESPE), ELS (ELS, Saremco), Tetric EvoCeram (TEC, Ivoclar-Vivadent), TPH3 (TPH3, Dentsply), QuixFil (QXF, Dentsply), Grandio (GRO, Voco) after pre-treatment with appropriate adhesives. The specimens (n=5 per material) were light-cured (60s, Elipar Freelight 2, 3M ESPE) and the dimensional change was recorded until 1h after cure with a Linear Variable Displacement Transducer placed on the thinner cavity wall.

Results: The following table shows the cusp deformation (µm) after 1h. Standard deviations are given in parentheses. All data were analyzed by ANOVA and multiple comparisons using Fisher's LSD procedure (p<0.05). Means with the same superscripted letters are statistically the same.

Conclusion: Multiple statistically significant differences were found. Filtek Silorane showed the lowest polymerization-induced cusp deformation of all materials tested.