IADR Abstract Archives

Comprehensive Study of Different Shrinkage Stress Characterization Methods

Objective: Composites with reduced polymerization shrinkage stress (PSS) have received significant attention. One key issue in comparing low stress materials is the significant difference in PSS measurement techniques. This study aims to systematically evaluate the performance of a reduced PSS material, SureFil SDR Flow™ and other composites using three different PSS techniques.

Method: 13 flowable and 19 universal composites were investigated. PSS was evaluated by 1) Cantilever Beam-based ADAF Tensometer, capable of providing adjustable beam compliance and real-time monitoring of polymerization kinetics by utilizing coupled Near-IR spectroscopy. Material was injected into a 2.25xΦ6mm cell followed by light-curing; 2) Photoelastic Method: material was filled into 4xΦ4mm cavity in photoelastic plates. PSS was calculated from diameter of 1st-order isochromatic ring curves; 3) Stress-Strain-Analyzer: Sample (2xΦ4mm) was placed between two Al attachments with one connected to load sensor and the other to a Piezo-actuator.

Result: Two separate rounds of testing using Tensometer found: among total of 9 flowable and 11 universal composites studied in Round-1, PSS ranges from 1.6 MPa (SureFil SDR Flow™) to 4.8 MPa (Grandio Flow); Among total of 4 Bulk-Fill flowable and 6 Bulk-Fill universal composites evaluated in Round-2, PSS ranges from 1.6 MPa (SureFil SDR Flow™) to 3.2 MPa (HypeFil DC). SureFil SDR Flow’s PSS as a function of time curves also reproduce very well between two rounds of testing. Photoelastic analysis showed SDR has significantly lower PSS than Filtek Supreme XT and Clearfil Majesty Posterior (ANOVA, p<0.05). Results from Stress-Strain-Analyzer revealed SureFil SDR Flow™ achieved the lowest PSS (1.1 MPa), whereas Filtek Supreme Flow obtained the highest PSS (6.5 MPa).

Conclusion: The key differences between the three PSS techniques were methodology and compliance. The tensometer method showed excellent repeatability and reproducibility. SureFil SDR Flow’s PSS is among the lowest when comprehensively evaluated by all three test methods.

IADR/LAR General Session
2012 IADR/LAR General Session (Iguaçu Falls, Brazil)
Iguaçu Falls, Brazil
2012
111
Dental Materials 7: Polymer-based Materials-Physical Properties and Performance
  • Lu, Hui  ( DENTSPLY International, Milford, DE, USA )
  • Jin, Xiaoming  ( DENTSPLY International, Milford, DE, USA )
  • Koltisko, Bernard  ( DENTSPLY International, Milford, DE, USA )
    • Oral Session
    Resin-Composites: Shrinkage and Clinical Effects
    06/20/2012