Influence of curing mode and time on degree of conversion of one conventional and two self-adhesive resin cements.
This study evaluated the effect of curing mode (auto- and dual-polymerizing mode) and time interval (5, 10 and 15 minutes) on the degree of conversion of resin cements. One conventional dual-cured resin cement (Panavia F 2.0 [Kuraray Medical Inc]) and two self-adhesive cements (RelyX Unicem [3M ESPE] and BisCem [BISCO, Inc]) were evaluated. The products (n = 5) were manipulated according to the manufacturer's instructions and applied to the surface of a horizontal attenuated reflectance unit attached to an infrared spectrometer. The materials were either light-cured for 40 seconds (dual-polymerizing mode) or allowed to auto-polymerize. The degree of conversion was calculated according to changes in the aliphatic-to-aromatic peak ratios prior to and 5, 10 and 15 minutes after light-activation or after mixing when the specimens were allowed to auto-polymerize. Data (%) were analyzed by two-way repeated measure ANOVA (curing mode and time interval) and Tukey's post-hoc test (alpha = 0.05%). The light-activating mode led to a higher degree of conversion values than the self-curing mode in self-adhesive cements (RelyX Unicem and BisCem), while there was no difference in the degree of conversion between the self- and light-cured groups of Panavia F 2.0 resin cement. All products showed a higher degree of conversion at 15 minutes postcuring than any other evaluation interval. The self-adhesive cements provide a higher degree of conversion values when light-activated. After 15 minutes of polymerization initiation, the degree of conversion was higher in all resin cements, regardless of the curing mode.
State University of Campinas, Department of Restorative Dentistry, Piracicaba, SP, Brazil. thaianeaguiar@fop.unicamp.br
Thaiane Rodrigues
TR
Aguiar
Marina
M
Di Francescantonio
Cesar A G
CA
Arrais
Gláucia Maria Bovi
GM
Ambrosano
Celso
C
Davanzo
Marcelo
M
Giannini
D002244:Carbon / Q000737:chemistry / Q000528:radiation effects; D003188:Composite Resins / Q000737:chemistry / Q000528:radiation effects; D055117:Curing Lights, Dental; D006801:Humans; D008422:Materials Testing; D044367:Phase Transition; D055668:Photochemical Processes; D011108:Polymers / Q000737:chemistry / Q000528:radiation effects; D019279:Resin Cements / Q000737:chemistry* / Q000528:radiation effects; D013055:Spectrophotometry, Infrared; D013997:Time Factors
C542562:BisCem cement; D003188:Composite Resins; C438843:Panavia-Fluoro; D011108:Polymers; C483701:Rely X Unicem; D019279:Resin Cements; D002244:Carbon