TY - JOUR
T1 - Indirect restoration thickness and time after light-activation effects on degree of conversion of resin cement
AU - Ayres, Ana Paula Almeida
AU - Andre, Carolina Bosso
AU - Pacheco, Rafael Rocha
AU - Carvalho, Adriana Oliveira
AU - Bacelar-Sá, Renata Cantanhede
AU - Rueggeberg, Frederick Allen
AU - Giannini, Marcelo
N1 - Publisher Copyright:
© 2015, Associacao Brasileira de Divulgacao Cientifica. All rights reserved.
PY - 2015/8/1
Y1 - 2015/8/1
N2 - This study evaluated the effects of indirect restorative materials, curing conditions and time on the degree of conversion (DC) of a dual-cured resin cement using infrared spectroscopy. The resin cement (RelyX Unicem 2, 3M ESPE) was applied to the diamond surface of a horizontal attenuated-total-reflectance unit and activated using one of following conditions: self-cure, direct light exposure, light exposure through indirect restorative materials (resin nano-ceramic: Lava Ultimate, 3M ESPE or feldspathic ceramic: Vita Blocks Mark II, Vita Zahnfabrik). Four thicknesses (0.5, 1.0, 1.5 or 2.0 mm) of each indirect material were analyzed, and the light-activation was performed using a blue LED light. Data (n=5) were analyzed by three-way ANOVA, Tukey’s post hoc and Dunnett’s tests (α=5%). No significant differences in DC were observed between indirect materials of similar thickness. All groups exhibited higher DC after 10 min than after 5 min. At both times points, the self-cure group exhibited significantly lower DC than all the light exposure groups. Only when the overlying indirect restoration had a thickness of 2 mm did DC decrease significantly. The presence of a thick, indirect restoration can decrease the DC of resin cement. DC after 10 min was higher than after 5 min. The self-cure mode yielded lower DC than the light-activating one.
AB - This study evaluated the effects of indirect restorative materials, curing conditions and time on the degree of conversion (DC) of a dual-cured resin cement using infrared spectroscopy. The resin cement (RelyX Unicem 2, 3M ESPE) was applied to the diamond surface of a horizontal attenuated-total-reflectance unit and activated using one of following conditions: self-cure, direct light exposure, light exposure through indirect restorative materials (resin nano-ceramic: Lava Ultimate, 3M ESPE or feldspathic ceramic: Vita Blocks Mark II, Vita Zahnfabrik). Four thicknesses (0.5, 1.0, 1.5 or 2.0 mm) of each indirect material were analyzed, and the light-activation was performed using a blue LED light. Data (n=5) were analyzed by three-way ANOVA, Tukey’s post hoc and Dunnett’s tests (α=5%). No significant differences in DC were observed between indirect materials of similar thickness. All groups exhibited higher DC after 10 min than after 5 min. At both times points, the self-cure group exhibited significantly lower DC than all the light exposure groups. Only when the overlying indirect restoration had a thickness of 2 mm did DC decrease significantly. The presence of a thick, indirect restoration can decrease the DC of resin cement. DC after 10 min was higher than after 5 min. The self-cure mode yielded lower DC than the light-activating one.
KW - Ceramic
KW - Composite
KW - Degree of conversion
KW - Light-activation
KW - Resin cement
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U2 - 10.1590/0103-64402013x0024
DO - 10.1590/0103-64402013x0024
M3 - Article
C2 - 26312973
AN - SCOPUS:85047699029
SN - 0103-6440
VL - 26
SP - 363
EP - 367
JO - Brazilian dental journal
JF - Brazilian dental journal
IS - 4
ER -