as well as a micro hybrid composite. 11 A further
optimization can be reached by using multimodal
filler compositions. 13 Another possibility is to use
resins which shrink less (e.g. larger molecules, which
means less double bonds to be reacted); however,
these monomers should have a low viscosity in order
to be able to wet the filler particles. 11 Finally, on the
monomer side, longer spacers can be built between
the reactive sites, which allow for stress relief after
polymerization. 8
Czasch & Ilie 5 showed that curing Sure Fill SDR
(DENTSPLY DeTrey GmbH, Konstanz, Germany)
and Venus Bulk-fill (Heraeus Kulzer GmbH,
Hanau, Germany) in 4-mm bulks for 20 s can be
recommended based on FTIR and micro hardness
data. Ilie et al. 14 reported the same results with
Tetric EvoCeram Bulk-fill (Ivoclar Vivadent) and X-tra
base (VOCO GmbH, Cuxhaven, Germany). There
is a growing body of literature demonstrating that
the bulk-fill concept is validated, when considering
curing depth, mechanical properties in the cervical
area, and margin quality. 1-8 However, it is still not
known if the modifications in the composition have
an influence on the wear behavior of the bulk-fill
composites. Therefore, the objective of the present
study was to compare the wear behavior of different
bulk-fill restorative materials as well as enamel in
vitro.
The null hypotheses tested were: (1) bulk-fill
composites show the same amount of wear and (2)
the wear of composites is equal to the wear of the
enamel.
2. Materials and Methods
The following bulk-fill materials were used: (X-tra
fil, [X], Voco), (Tetric N-Ceram Bulk Fill, [T], Ivoclar
Vivadent) and (QuiXX, [Q], Dentsply,). Eight samples
were prepared for each brand according to the
manufacturer recommendations.
Thirty-two aluminum sample holders (inner Ø 7.9
mm, depth 1.5 mm) were grit-blasted with 27 µm
aluminum oxide particles (EtchMaster Tips Small,
Groman, USA), then one coat of universal primer
(Monobond Plus, Ivoclar Vivadent) was added and
left for 60 s, followed by air blasting to evaporate the
solvent. Then one coat of adhesive (Optibond FL 2,
Kerr, USA) was applied and light-cured for 10 s using
the Bluephase G2 unit at “High” mode delivering
1450 mW/cm 2 and having a radiant exposure of 14.5
J/cm 2 at a distance of 1.5 mm (verified with MARC
Resin calibrator, Bluelight Analytics Inc., Halifax,
NS). The composites [Q], [T] and [X] were filled
into 24 sample holders (n=8/each material) in one
increment, then the top surface was flattened with a
Mylar® matrix band and light-cured at high mode for
10s (Bluephase G2).
The composite surfaces were finished and polished
by using silicon carbide discs (Sof-Lex , 3M, St. Paul,
MN, USA), light orange disc for finishing and yellow
disc for polishing, each for 15 s. All samples were
then stored in distilled water at 37º C for 3 weeks.
Human enamel samples were obtained from
extracted incisors, stored in 0.4% chloramine solution.
The IRB1 of the University of Florida allowed the use
Stomatology Edu Journal
of extracted teeth, if they are completely anonymized
(IRB.UF 201500060). They were mounted with
adhesive technology as described above for the
steatite antagonists on eight grit blasted aluminum
sample holders for the chewing simulator CS 4.8
(Mechatronik, Germany), perpendicular to the long
axis of the sample holder. They were then ground
flat and polished using the pre