Purpose: This in vitro study aimed to evaluate the shear bond strength
(SBS) of particulate filler composite (PFC) to saliva- or
water-contaminated fiber-reinforced composite (FRC).
Materials and
Methods: One type of FRC substrate with semi-interpenetrating polymer
matrix (semi-IPN) (everStick C&B) was used in this investigation. A
microhybrid PFC (Filtek Z250) substrate served as control. Freshly cured
PFC and FRC substrates were first subjected to different contamination
and surface cleaning treatments, then the microhybrid PFC restorative
material (Filtek Z250) was built up on the substrates in 2-mm increments
and light cured. Uncontaminated and saliva- or water-contaminated
substrate surfaces were either left untreated or were cleaned via
phosphoric acid etching or water spray accompanied with or without
adhesive composite application prior applying the adherent PFC material.
SBS was evaluated after thermocycling the specimens (6000 cycles, 5°C
and 55°C).
Results: Three-way ANOVA showed that both the surface
contamination and the surface treatment signficantly affected the bond
strength (p < 0.05). Saliva contamination reduced the SBS more than
did the water contamination. SBS loss after saliva contamination was
73.7% and 31.3% for PFC and FRC, respectively. After water
contamination, SBS loss was 17.2% and 13.3% for PFC and FRC,
respectively. The type of surface treatment was significant for PFC (p
< 0.05), but not for FRC (p = 0.572).
Conclusion: Upon
contamination of freshly cured PFC or semi-IPN FRC, surfaces should be
re-prepared via phosphoric acid etching, water cleaning, drying, and
application of adhesive composite in order to recover optimal bond
strength.