Effect of treated filler loading on the photopolymerization inhibition and shrinkage of a dimethacrylate matrix.
J Mater Sci Mater Med
; 19(5): 1881-9, 2008 May.
Article
in En
| MEDLINE
| ID: mdl-17914626
ABSTRACT
This study shows how treated filler loading influences the photopolymerization of a dimethacrylate comonomer mixture, regarding, in particular, shrinkage and inhibition under atmospheric oxygen, present in oral environment. Bis-GMA/TEGDMA (75/25 wt.%) resins were loaded with hybrid filler (Ba aluminosilicate glass and pyrogenic silica), treated with gamma-methacryloxy(propyl)trimethoxysilane, at 0-50 wt.% and light cured over a total of 30 s (45 mW/cm2). Degree of double-bond conversion (DC), obtained using FTIR, decreased with filler content. 1H MAS spectra (293-340 K) and STRAFI images (293 K) were obtained as a function of irradiation time and filler concentration. 1H signals of unreacted methacrylate groups were more intense for higher loaded resins and resonances from -CH2SiO2(OH) (T2) and -CH2SiO3- (T3) units, also observed by 29Si NMR, were resolved and suggest the presence of T2-resin bonds. 1D images show a reduction on polymerization contraction and reaction inhibition at the composite resin surface with filler loading. 2D resin images present a highly mobile surface layer, hence with lower DC.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Oxygen
/
Photochemistry
/
Dental Materials
/
Methacrylates
Language:
En
Journal:
J Mater Sci Mater Med
Journal subject:
ENGENHARIA BIOMEDICA
Year:
2008
Document type:
Article
Affiliation country:
Portugal