Bonding performance of a self-adhering flowable composite to indirect restorative materials

Resumo

Simplified restorative materials may be a logical
next step for dental manufacturers. Objective: The aim of this
study was to evaluate the shear bond strength of a self-adhering
flowable composite to four substrates used in indirect technique.
Material and methods: Twenty-four samples (5 mm wide, 15 mm
length and 2 mm thick / six blocks each substrate) were prepared
in the dental prosthetic laboratory. The following materials were
used: ceromer (SR Adoro/AD, Ivoclar Vivadent), leucite ceramic (IPS
Empress Esthetic/EE, Ivoclar Vivadent), zirconia ceramic (ZirCAD/ZI,
Ivoclar Vivadent); metal ceramic alloy (Fit Cast SB/ME, Talladium
do Brasil). Samples of each substrate were divided into two groups (n = 3). Two flowable composites (Control/FF – Filtek Z350 XT
Flow/3M ESPE, and the self-adhering/DF – Dyad Flow/Kerr) were
bonded to the four substrates. Four Tygon tubings were positioned
over each sample, which were filled in with the composites FF and
DF, and visible light-cured for 20 s. The tubings were removed to
expose the specimens (12 per group) in format of cylinders and
samples were stored in distilled water at 37±2°C for one week.
After this period, each sample was attached to testing machine
and the specimens were submitted to the shear bond strength test
at speed of 1.0 mm/min, until failure. The results were analyzed
by two-way ANOVA and Tukey test (p < 0.05). Results: The means
(SD) were (in MPa): AD + FF = 34.4 ± 4.9; AD + DF = 28.2 ±
4.2; EE + FF = 29.7 ± 5.8; EE + DF = 32.3 ± 6.9; ZI + FF =
23.2 ± 5.4; ZI + DF = 8.5 ± 1.5; ME + FF = 28.9 ± 4.2; ME +
DF = 31.7 ± 4.5. Conclusion: The efficacy of flowable composites
is material-dependent. The self-adhering composite provided lower
bond strength only to zirconia ceramic. Comparing with the control
group, Dyad Flow showed lower bond strength to the ceromer and
zirconia ceramic.