Polymerization Kinetics of Five Restorative Composites
Objectives: To test the hypothesis that resin-based composites (RBC) with higher Depth of Cure (DoC) and Volumetric Shrinkage (VS) will experience higher Degree of Conversion (DC%) and Rate of Polymerization (Rp). Methods: Conventional RBC’s (3M Filtek Supreme Ultra – FSU; 3M Filtek Universal Restorative – FUR; BISCO prototype Universal Composite - BUC) were tested alongside bulk-fill resin composites (BISCO Reveal HD Bulk – RHDB; 3M Filtek One Bulk Fill -FOBF). DC% was measured at the top (0 mm) and bottom surfaces (2 mm for conventional composites; 2 and 4 mm for bulk-fill composites) by FTIR calculated from aliphatic and aromatic C=C absorption signals. Rp was calculated as the first derivative of DC% when collected at 1 scan/s during light-curing. VS was measured 10 min after curing by AcuVol (BISCO). DoC was determined following ISO 4049:2019. All tests were performed on A3 shades (n=3) and light-cured by VALO LED with approximately 20 J/cm2. Results: Differences in DC% and Rp were statistically analyzed (ANOVA, Tukey, p<0.05) for each composite and each depth. At each depth, RHDB had higher DC% than the other RBC. For DC%, FOBF did not differ statistically from the three conventional composites at 0 mm, but DC% was lower than BUC at 2 mm. For both bulk-fill and conventional composites, the RBC with highest DoC showed the highest Rp. Despite DoC observed when following ISO 4049, deeper parts of the composite may be less polymerized. Conversely, higher DoC materials may exhibit higher rates of curing, a risk factor for volumetric shrinkage and/or shrinkage stress. Conclusions: The trends in DC% and Rp weakly corresponded to trends in VS and DoC. The hypothesis cannot be fully accepted solely based on this data, but the RBC with highest DoC did have highest DC%, Rp, and VS.
Division: Meeting:2023 IADR/LAR General Session with WCPD Location: Year: 2023 Final Presentation ID:0281 Abstract Category|Abstract Category(s):Dental Materials 2:Polymer-based Materials
Authors
Sedlacek, Timothy
( BISCO
, Schaumburg
, Illinois
, United States
)
Oliveira, Dayane
( University of Florida
, Gainesville
, Florida
, United States
)
Rocha, Mateus
( University of Florida
, Gainesville
, Florida
, United States
)
Triplett, Amelia
( BISCO
, Schaumburg
, Illinois
, United States
)
Yu, Erick
( BISCO
, Schaumburg
, Illinois
, United States
)
Suh, Byoung
( BISCO
, Schaumburg
, Illinois
, United States
)
Sinhoreti, Mario
( University of Florida
, Gainesville
, Florida
, United States
; Piracicaba Dental School, UNICAMP
, Piracicaba, SP
, Brazil
)
Financial Interest Disclosure: Authors Timothy Sedlacek, Amelia Triplet, Erick Yu, and Byoung Suh are employees of BISCO, which funded this submission and owns some of the products tested.