Objectives: To synthesize and evaluate the performance of novel low shrink monomers in a dental composite versus a control of 3M FiltekTM Supreme XT Restorative (FS).
Method: Novel low shrink monomers, both methacrylated cyclic allylic disulfides and derivatives of BisGMA, were synthesized. Experimental composite pastes were made from photo-initiator activated resins containing the new low shrink monomers, BisEMA6, and UDMA. The resins were filled with a filler system containing a silane-treated nano-sized silica with particle size of approximately 20 nanometers and a silane treated Zirconia-silica nano-cluster filler. The experimental composite was evaluated against FiltekTM Supreme XT Restorative (control). Reported here are polymerization shrinkage (volumetric change), diametral tensile and the depth of cure. Test results were analyzed using ANOVA one-way analysis.
Results:
Test | Experimental Composite | FiltekTM Supreme XT Restorative |
Shrinkage (%) | 1.42(0.08) | 1.92(0.06) |
Diametral Tensile Strength (MPa) | 74.58(5.07) | 74.48(1.98) |
Depth of cure (mm) | 3.83(0.18) | 3.59(0.08) |
Fracture Toughness (K1c) | 1.30 (0.04) | 1.32 (0.05) |
ANOVA one-way analysis indicated that the experimental composite exhibits a significantly lower polymerization shrinkage compared to FiltekTM Supreme XT Restorative (p < 0.05). Analysis of diametral tensile strength, depth of cure, and short rod fracture toughness tests showed that the two composites are statistically equivalent in these properties (p > 0.05)
Conclusion: The experimental dental composite, which includes the synthesized novel low shrink monomers, exhibited a significantly lower polymerization shrinkage compared to the FiltekTM Supreme XT Restorative, while other physical properties such as the diametral tensile strength, depth of cure, and fracture toughness were statically equivalent for the two composites.