Abstracts of the Academy of Dental Materials Annual ... - IsiRed

38 ◦ C (G38), 80 ◦ C (G80) or 100 ◦ C (G100) for 60 s. Half of the
specimens of each group were rinsed with water at 80 ◦ C for
15 s (B). ATR-FTIR was performed using a spectrometer and
zinc selenide crystal.
Results ATR-FTIR analyses showed a band at 1637 cm −1 in
G20 referring to �(O–H), which disappeared in other IR spectra,
and changes in Si–O peaks with an enlarged band around
940 cm −1 and a decrease in the band at 1296 cm −1 , assigned
to the ester group, after heat treatment (G38, G79, G100). The
spectra of silane submitted to rising with 80 ◦ C water (G20b,
G38b, G79b and G100b) showed a pattern of bands with intensity
variation only, without wave-number shifts.
Conclusions The results suggested that heat treatments or
rinse with water at 80 ◦ C after silane application could improve
the silane layer network.
doi:10.1016/j.dental.2010.08.129
122
Clinical follow-up of direct adhesive bridges up to 7 years
M. Özcan
University of Zurich, Dental Materials Unit, Clinic for Fixed and
Removable Prosthodontics, Zurich, Switzerland
Objectives: This study evaluated the clinical performance
of direct, one-pontic, inlay-retained, fiber-reinforcedcomposite
restorations (DOI-FRC) up to 7 years.
Materials and methods: Between June 2002 and June 2009,
55 patients (39 females, 16 males, 23–83 years old) received
a total number of 75 posterior DOI-FRCs (n = 43 mandible,
n = 32 maxilla). Box preparations were made on the abutments.
Teeth were conditioned using a three-step adhesive system
(Quadrant Unibond Primer and Sealer, Cavex). All restorations
were made under rubber-dam directly. Restorations were constructed
with unidirectional, preimpregnated E-glass fibers
(everStick C&B, StickTech) using one type of resin composite
(Clearfil Photo Posterior, Kuraray). Colour was improved using
flowable composites (Sinfony, 3M ESPE). After baseline recordings,
patients were followed at 6 months and at annual recalls.
Patients were instructed to call upon experience of a failure or
any kind of intervention. The evaluation criteria involved technical
failures such as chipping or fracture (tooth/restoration)
and caries.
Results: During the observation period, a total of 3 debondings
in the inlay cavities, and 3 chippings were observed
on the buccal surfaces of pontics within 1 and 2 years’
recall. Chippings were repaired using CoJet system (3M ESPE)
and remained functional until the last follow up date. Two
restorations could not be observed after 1 year and 2 years,
respectively due to caries and subsequent bridge construction.
Based on the life-tables calculated from the data, estimated
survival rate up to 7 years was 95.3% [Kaplan–Meier, Log Rank
(Mantel–Cox) 95% CI].
Conclusions: Direct, one-pontic, inlay-retained, FRC
restorations with the adhesive system, veneering composite
and the technique used, offer acceptable clinical survival rate.
doi:10.1016/j.dental.2010.08.130
dental materials 26S (2010) e1–e84 e57
123
Adhesive behaviour of resin-based sealer cements in thin and
thick layers
E.S. Pane 1 , J.E.A. Palamara 2 , H.H. Messer 2
1 University of Melbourne, Australia and University of Sumatera
Utara, Medan, Indonesia
2 University of Melbourne, Australia
Objectives: In root canal treatment, a thin layer of sealer
cement is recommended for obturation. However, with resinbased
sealers, lower bond strength has been shown in thin
layer compared to thick (Jainaen et al., IEJ 2007 40:882). This
contradicted the finding with resin composite restorative
materials which showed that tensile strength decreased gradually
with increasing thickness (Alster et al., J Dent Res 1995
74:1745). The aim of this study was to evaluate tensile and
shear strength of thin and thick layers of three resin-based
sealers (methacrylate-based: EndoREZ, Ultradent; RealSeal,
SybronEndo; and epoxy-based: AH Plus, Dentsply).
Materials and methods: Thin and thick layers of sealer
cements were prepared between metal-to-metal joints of
plano-parallel stainless steel aligned rods with diameter
4.7 mm. Ten samples of thin layers averaged 0.1 mm and
thick layers 1.0 mm were prepared for each group of sealer,
measured from the layer images by Image Tool (UTHSCSA).
Tensile and shear strength were tested after 48 h for the
methacrylate-based and 7 days for the epoxy-based material
using a universal testing machine (Instron model 5544)
with a crosshead speed of 1 mm/s. Force data were used
to calculate the bond strength (MPa). Modes of failure were
examined under magnification and replicas of the fractured
surfaces were examined with SEM (Quanta FEG SEM,
FEI Co.). Data were analyzed using two-way ANOVA (SPSS
Statistics 17.0).
Results: Higher mean tensile and shear strength of thin
layers than the thick were found in the methacrylate-based
sealers (statistically significant, p < 0.05). For the epoxy-based
sealer, similar behaviour was found for the shear strength (not
statistically significant), and the opposite tendency in the tensile
strength (p < 0.05) with higher values in thick layers. There
was no association between thicknesses and mode of failure.
However, numerous voids were noted with thin layer of AH
Plus.
Conclusions: The behaviour of resin-based sealers was
influenced by layer thickness. Further study regarding the
behaviour of resin-based sealer in different thicknesses
applied to root dentin will be undertaken.
doi:10.1016/j.dental.2010.08.131