Purpose: To evaluate the bond strength between composite resin and feldspathic ceramic following repair protocols
with and without hydrofluoric acid and aging by thermocycling.
Materials and Methods: Forty-eight glass feldspathic ceramic blocks (8 x 8 x 6 mm) were divided into three groups
on the basis of their surface repair treatment: 1. 10% hydrofluoric acid + Signum Ceramic Primer I + Signum Ceramic
Primer II (control group); 2. abrasive rubber tips + Signum Ceramic Primer I + Signum Ceramic Primer II (test
group); 3. Signum Ceramic Primer I + Signum Ceramic Primer II (negative control group). The treated surface of
each block was built up with composite and then sectioned to produce nontrimmed bars (adhesive area = 1 mm2).
Half of the bars from each group were aged by 6000 cycles of 30-s immersions in water baths at 5°C and 55°C,
with a transfer time of 2 s. The other bars were immediately subjected to microtensile bond strength testing. The
mean bond strength for each block was then recorded and submitted to two-way ANOVA and Tukey’s test
(α = 0.05).
Results: The aging protocol influenced the bond strength values of all groups (p = 0.000). The non-aged groups
submitted to surface treatment protocols 1 (13.1 ± 2.5 MPa) and 2 (11.5 ± 5.1 MPa) presented the highest bond
Conclusions: The interface bond strength of all groups was susceptible to aging. Surface treatment protocol 2,
with abrasive rubber tips and no hydrofluoric acid, appeared to be the most promising option, as the resulting bond
strength values were similar to those of the control group.