ABSTRACT
Objective: This study aimed to evaluate the impact of extended photoactivation time
on ultimate tensile strength (UTS), water sorption (WS) and solubility (WSB) of resin-based
materials used as fissure-sealants
Methods: A fissure-sealant (Fluroshield) and a flowable composite (Permaflo) polymerized
for 20 and 60 seconds were tested. For UTS, 20 hourglass shaped samples were prepared
representing two materials and two photoactivation time (n=5). After 24-h dry-storage,
samples were tested in tension using a universal testing machine at a cross-head speed
of 0.5 mm/min (UTS was calculated in MPa). For WS and WSB, 20 disks with 5 mm diameter
and 1 mm height (n=5) were prepared and volumes were calculated (mm3). They were transferred
to desiccators until a constant mass was obtained (m1) and were subsequently immersed
in distilled water until no alteration in mass was detected (m2). Samples were reconditioned
to constant mass in desiccators (m3). WS and WSB were determined using the equations
m2-m3/V and m1-m3/V, respectively. Data were subjected to twoway ANOVA and Tukey’s
HSD test (P<.05).
Results: There was no significant difference between materials or photoactivation
times for the UTS and WS. Permaflo presented lower but negative WSB compared to Fluroshield.
Conclusions: Extended photoactivation time did not improve the physical properties
tested. Fluroshield presented physical properties that were similar to or better than
Permaflo. (Eur J Dent 2012;6:402-407)
Key words
Fissure sealant - photoactivation time - ultimate tensile strength - water sorption
- water solubility
