TY - JOUR
T1 - Factors affecting photopolymerization stress in dental composites
AU - Pfeifer, C. S.
AU - Ferracane, J. L.
AU - Sakaguchi, R. L.
AU - Braga, R. R.
PY - 2008/11
Y1 - 2008/11
N2 - 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.
AB - 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.
KW - Dental composite
KW - Irradiance
KW - Polymerization stress
KW - Reaction kinetics
KW - Volumetric shrinkage
UR - http://www.scopus.com/inward/record.url?scp=58149269575&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=58149269575&partnerID=8YFLogxK
U2 - 10.1177/154405910808701114
DO - 10.1177/154405910808701114
M3 - Article
C2 - 18946012
AN - SCOPUS:58149269575
SN - 0022-0345
VL - 87
SP - 1043
EP - 1047
JO - Journal of dental research
JF - Journal of dental research
IS - 11
ER -