Resin-modified glass-ionomer setting reaction competition.
Resin-modified glass ionomers (RMGI) set by at least 2 mechanisms dependent upon reactant diffusion prior to gelation. Each reaction's kinetics and setting mechanism may rely on and/or compete with the other. In this study, we investigated RMGI setting reaction interactions using differential scanning calorimetry (DSC) by varying light-cure initiation times. A RMGI was analyzed with isothermal and dynamic temperature scan DSC with light-curing occurring immediately, or at 5 or 10 minutes after mixing as well as without light-activation. Results show that as time allowed for the acid-base reaction increased, the light-activation polymerization exotherm decreased. Conversely, analysis of DSC data suggests that earlier light-activation may limit the acid-base reaction and result in a different structured material. During early RMGI development, acid-base and light-polymerization reactions compete with and inhibit one another.
Berzins
D W
DW
Dental Biomaterials, School of Dentistry, Marquette University, Milwaukee, WI, USA.
Abey
S
S
Costache
M C
MC
Wilkie
C A
CA
Roberts
H W
HW
D000136:Acid-Base Equilibrium; D002152:Calorimetry, Differential Scanning; D055598:Chemical Phenomena / Q000528:radiation effects; D003188:Composite Resins / Q000737:chemistry*; D005899:Glass Ionomer Cements / Q000737:chemistry*; D055115:Light-Curing of Dental Adhesives / Q000379:methods*; D011108:Polymers / Q000737:chemistry; D012117:Resins, Synthetic / Q000737:chemistry*
D003188:Composite Resins; C079765:Fuji II LC cement; D005899:Glass Ionomer Cements; D011108:Polymers; D012117:Resins, Synthetic