IADR Abstract Archives
Conversion vs. Shrinkage of N'Durance, Dimer Acid based Nanohybrid Composite
Several approaches to improved dental composites have been studied. One of these approaches is to increase the biocompatibility by increasing the monomer conversion and thereby reducing the elution of components. Great strides have been made, but manufacturers battle the problem of an increase in shrinkage contraction and stress when the monomer conversion increases.
Objectives: To determine the relationship between Monomer conversion and volume shrinkage of the new N'Durance, dimer acid based nanohybrid composite, compared to 16 different commercialized products.
Methods: The polymerization shrinkage was measured using a linometer from ACTA. Monomer conversion was calculated by near IR measuring the peak area corresponding to C=C bond before and after polymerization. The % of double bond conversion was calculated using the equation:
Conversion % = 1 – (Acured/Auncured) x 100
Specimens were polymerized using a quartz-tungsten-halogen lamp with an intensity of 500 mW/cm2, during 40 seconds whatever the test is.
Results:
Product | Manufacturer | Type | Monomer conversion % | Volume Shrinkage % |
Image | Septodont | Universal/Microhybrid | 59.0±1.4 | 2.3±0.3 |
N'Durance | Universal/Nanohybrid | 75.0±1.5 | 1.4±0.4 | |
Filtek-Supreme+ | 3M-ESPE | Universal/Nanofilled | 47.2±6.5 | 1.9±0.2 |
Filtek-Z100 | Universal/Microhybrid | 57.5±1.3 | 2.1±0.3 | |
Filtek-Z250 | Universal/Microhybrid | 52.5±1.2 | 1.9±0.4 | |
Esthet-X | Dentsply-Caulk | Universal/Microhybrid | 60.7±5.6 | 3.0±0.3 |
TPH3 | Universal/Nanohybrid | 52.5±6.4 | 2.5±0.5 | |
Gradia-Direct-A | GC-America | Anterior/Microfilled | 42.5±2.1 | 2.2±0.1 |
Gradia-Direct-P | Posterior/Microfilled | 47.5±5.0 | 2.0±0.1 | |
Solitaire2 | Heraeus-Kulzer | Posterior/Condensable | 64.1±1.9 | 3.0±0.1 |
Heliomolar | Ivoclar-Vivadent | Universal/Microfilled | 41.8±2.8 | 1.5±0.1 |
Alert | Jeneric-Pentron | Posterior/Condensable | 61.5±3.5 | 2.8±0.2 |
Artiste | Universal/Nanofilled | 56.6±2.2 | 2.4±0.4 | |
Simile | Universal/Nanohybrid | 56.1±2.0 | 2.4±0.3 | |
Herculite-XRV | Kerr | Universal/Microhybrid | 64.6±1.5 | 2.8±0.1 |
ELS | Saremco | Universal/Microhybrid | 54.0±3.5 | 1.7±0.3 |
Grandio | VOCO | Universal/Nanohybrid | 44.7±3.0 | 2.0±0.2 |
Conclusions: Trying to increase the final double bond conversion to reduce the unreacted monomers, of the marketed products, which use conventional resin Bis-GMA – TEGDMA, the volumetric shrinkage also increases. N'durance, which uses a new resin system based on a dimer acid derivative monomer, shows a unique response: high conversion and low polymerization shrinkage.