Linked Life Data

17143740

Source:http://linkedlifedata.com/resource/pubmed/id/17143740

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2007-5-15
pubmed:abstractText
A commercial photopolymerizable resin-modified glass-ionomer (Fuji II LC) was studied using a variety of nuclear magnetic resonance (NMR) techniques. (1)H and (19)F stray-field imaging (STRAFI) enabled to follow the acid-base reaction kinetics in self-cured (SC) samples. Gelation and maturation processes with 25 min and 40 h average time constants, respectively, were distinguished. In self- & photo-cured (SPC) samples, two processes were also observed, which occurred with 2 s and 47 s average time constants. (1)H, (27)Al and (29)Si magic angle spinning (MAS) NMR, (13)C cross-polarization (CP)/MAS NMR and (27)Al multiple quanta (MQ)MAS NMR spectroscopy were used to obtain structural information on the glass and cements that were either SC or SPC. The presence of methacrylate groups was identified in the solid component. Unreacted hydroxyl ethylmethacrylate (HEMA) was detected in self-cured cement. (27)Al data showed that approximately 28% and 20% of Al is leached out from glass particles in SC and SPC samples, respectively. The upfield shift detected in (29)Si MAS NMR spectra of the cements is consistent with a decrease in the number of Al species in the second coordination sphere of the silicon structures. Scanning electron microscopy (SEM) showed existence of 3D shrinkage of the cement matrix in photo-cured cements.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0957-4530
pubmed:author
pubmed:issnType
Print
pubmed:volume
18
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
787-96
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Structural and spatially resolved studies on the hardening of a commercial resin-modified glass-ionomer cement.
pubmed:affiliation
Departamento de Engenharia de Materiais, Instituto Superior Técnico, Universidade Técnica de Lisboa, Lisboa, Portugal.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't