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Abstract
Objectives:
This study was undertaken to determine the effect of temperature on the
microhardness and viscosityof 4 resin compositematerials (
FiltekLS, FiltekSupremeUltra, Tetric
CeramHB, Vit-l-escence
).
Methods:
To investigate microhardness, samples of each of the 4 composite materials,
preparedby standard insertionof resin intoprefabricatedmoulds,weredivided into2groups
(n=10 per group). On the first group, the resin composite materials were inserted into the
moulds at room temperature and cured. On the secondgroup, the resin compositematerials
were pre-heated in a heating device, inserted into the moulds and immediately cured.
Microhardness after curing (both immediately and after 24hours of storage)was determined
(using a 300 g load applied for 10 seconds) and averaged for 5 randomly selectedpoints on
the top andbottom surfaces of each sample. To investigate viscosity, 0.5 g samples of room
temperatureor preheated resin composite (n=15per group) wereplacedunder a 454g load
for 45 secondsbefore light-curing (40 seconds). After curing, each samplewasphotographed
and the surface area calculated. Datawere analyzedby
t
tests or one-way analysis of variance
andTukey’s test.
Results:
Preheating the resin composites increased the microhardness and decreased
the viscosity of the samples.
Filtek Supreme Ultra
resin composite had the highest mean
microhardness, and
Vit-l-escence
resincompositehad the lowest viscosity.
Conclusions:
The effects of preheating resin composites may allow easier placement of
restorations andgreatermonomer conversion.
a
Effect of Preheating onMicrohardness andViscosity of
4RESINCOMPOSITES
The following is an abstract of a research article published in the
‘Clinical Review' section of
jcda.ca
—CDA’s online, open access
scholarly publication that features articles indexed inMedline,
Journal CitationReports and ScienceCitation Index.
KarenV.Ayub
DDS,MSc
GildoC.SantosJr.
DDS,MSc,PhD
AminS.Rizkalla
BSc,MEng,PhD
RichardBohay
DMD,MSc
LuisFernando
Pegoraro
DDS,MSc,PhD
JoséH.Rubo
DDS,MSc,PhD
M.JacintaM.C.Santos
DDS,MSc,PhD
ResearchAbstracts
