The study was aimed to investigate a color indicator containing dual
curing resin composite luting cement and to plot the color change to the
time of solidification of the cement. In addition some physical
properties were studied. Specimens were made of a dual-cure resin cement
(Maxcem Elite™ Chroma, Kerr, Orange, CA, USA) and polymerized by
autopolymerization only, or with light initiated polymerization. A
spectrophotometer was used to quantify the color change of the cement as
plotted with the curing time. The efficacy of the curing process was
studied by measuring water sorption and the ultimate flexural properties
of the cement. The results showed that the flexural strength of cement
after autopolymerization was 27.3 MPa and after light initiated
polymerization 48.1 MPa. Young's modulus of bending was 2089.3 MPa and
3781.5 MPa respectively for the same cement samples. Water sorption
after two weeks for the autopolymerization cement samples was -1.12 wt%
and for the light initiated polymerization samples 0.56 wt%.
Non-parametric Spearman's correlation was measured for autopolymerized
cement samples between variables for color and solidification load (N),
which showed a strong correlation between curing process and color
change (p < 0.05). There was a correlation between the color change
and degree of monomer conversion of the dual curing resin composite
luting cement which contained a color indicator system for
polymerization reaction. The study also suggested that
autopolymerization only resulted in suboptimal polymerization of the
cement. By additional light curing considerably higher flexural
properties were obtained.