Curing characteristics of flowable and sculptable bulk-fill composites
pp 1-12
First online:
Abstract
Objectives
The aim of this
study was to determine and correlate the degree of conversion (DC) with
Vickers hardness (VH) and translucency parameter (TP) with the depth of
cure (DoC) of five bulk-fill composites.
Materials and methods
Six specimens per
group, consisting of Tetric EvoCeram Bulk Fill (“TEC Bulk,” Ivoclar
Vivadent), SonicFill (Kerr), SDR Smart Dentin Replacement (“SDR,”
Dentsply), Xenius base (“Xenius,” StickTech; commercialized as EverX
Posterior, GC), Filtek Bulk Fill flowable (“Filtek Bulk,” 3M ESPE), and
Tetric EvoCeram (“TEC,” control), were prepared for DC and VH: two
2-mm-thick layers, each light-cured for 10 s; one 4-mm bulk-fill,
light-cured for 10 or 20 s; and one 6-mm bulk-fill, cured for 20 s. DC
was measured using a Fourier-transform infrared spectrometer, VH using a
Vickers hardness tester. DoC and TP were measured using an
acetone-shaking test and a spectrophotometer, respectively. Data were
analyzed using ANOVA and Pearson’s correlation (α = 0.05).
Results
DC and VH ranged
between 40–70 % and 30–80 VHN, respectively. TEC Bulk, Xenius, and
SonicFill, bulk-filled as 4-mm-thick specimens, showed bottom-to-top
hardness ratios above 80 % after 20 s curing. A positive linear
correlation was found for bottom DC and VH. An average DC ratio of 0.9
corresponded to a bottom-to-top VH ratio of 0.8.
Conclusions
Sculptable
bulk-fills require 20 s, whereas 10 s curing time was sufficient for
flowable bulk-fills using a high-intensity LED unit.
Clinical relevance
Clinicians should be
aware that longer curing times may be required for sculptable than
flowable bulk-fill composites in order to achieve optimal curing
characteristics.
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