Avtor/Urednik		Jevnikar, Peter
Naslov		Vpliv načina strjevanja na difuzijo vode in na mehanske lastnosti steklasto ionomernih cementov
Tip		monografija
Kraj izdaje		Ljubljana
Založnik		Medicinska fakulteta
Leto izdaje		1997
Obseg		str. 63
Jezik		slo
Abstrakt		Resin-modified glass ionomer cements (GIC) may be considered as an alternative to resin luting composites, due to their bonding characteristics and easy luting procedures. The aim of our work was to study the effect of setting mode and surface protection on water penetration into glass ionomer cement and it's mechanical properties. The contribution of acid-base reaction to the setting mechanism was also assesed. To visualise the water penetration into the GI samples magnetic resonance micro imaging was used. Three groups of samples were prepared: (i) visible-light cured (photopolymerization and acid-base reaction), (ii) visible light cured followed by surface protection, (iii) chemical cured in the dark. We also studied the effect of different setting modes and surface protection on flexural strength of resin modified GI. Three groups of samples were again prepared for each measuring time. Half of the samples of each group were immersed in distilled water at body temperature and the other half was kept dry as a control. Flexural strength was measured 1 hour, 24 hours and 7 days the start of mixing. It was demonstrated that the type of setting mode produces substantial differences in water penetration dynamics. It appears that light cured material withstands water penetration better than it's chemical cured variant. This would suggest that both setting reactions contribute to the final structure of the cement. In addition we studied the role of surface protection and according to the M microimages we can conclude that varnish is an effective barrier in the first 10 days, while later, water managed to penetrate through the coating. MR micro imaging is a good method for monitoring the water permeability of glass ionomer cements. The technique is nondestructive and makes it possible to follow up the process on the same sample without having to destroy it. (Abstract truncated at 2000 characters).
Deskriptorji		GLASS IONOMER CEMENTS ACRYLIC RESINS MAGNETIC RESONANCE IMAGING WATER PLIABILITY TENSILE STRENGTH POLYMERS LIGHT