Abstract
Polymerization stress development results from the complex interplay of volumetric shrinkage, reaction kinetics, and viseoelastic properties. The objective of this study was to examine the relationships among volumetric shrinkage, degree of conversion, rate of polymerization (RPmax J, and stress development for 2 model bis-GMA-based composites. Three irradianees were used - 220, 400, or 600 mW/em2 - with exposure times adjusted to deliver the same radiant energy. Volumetric shrinkage was determined with a mercury dilatomcter, degree of conversion and RPmax by differential scanning calorimetry (DSC), and polymerization stress with a low-compliance device (Sakaguchi et al. 2004b). Results indicated that polymerization reaction rate and shrinkage were not correlated. Irradiance was directly related to polymerization reaction rate and to stress development. The group with the highest stress/ degree of conversion exhibited the lowest RPmax, so it can be assumed, within the limitations of this study, that the conversion was most closely related to stress development.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1043-1047 |
| Number of pages | 5 |
| Journal | Journal of dental research |
| Volume | 87 |
| Issue number | 11 |
| DOIs | |
| State | Published - Nov 2008 |
| Externally published | Yes |
Keywords
- Dental composite
- Irradiance
- Polymerization stress
- Reaction kinetics
- Volumetric shrinkage
ASJC Scopus subject areas
- Dentistry(all)