Effect of Pepsi cola beverage on microhardness of composite resin polymerized with different curing lights (In vitro study)

Abstract

ABSTRACT
Background: Pepsi cola was reported to reduce composite surface microhardness also the microhardness of
composite resin affect by the type of light curing device, so the aim of this study was to compare between the
effect of Pepsi cola on microhardness of composite resin cured with conventional and LED light cures.
Material and methods: Sixteen disc specimens (10* 2mm) were fabricated from one type composite resin
(Composan LCM.). Half of the specimens were polymerized with (Astralis 5) conventional LC and the other half
with (Woodpecker) LED light cure. Vickers surface microhardness (VHN) was analyzed after 24 hrs aging in
distilled water. The specimens submitted to a five minutes immersion in Pepsi cola three times daily interrupted
by immersion in distilled water at (37 C˚). Surface microhardness measurements were done at 30, 60 day
intervals. Data were submitted to paired t-test.
Results: In comparison with the baseline readings there were high significant differences (P<0.000) in
microhardness of tested composite for both differently cured groups at the 1st and 2nd moths immersion period.
No statistical significant difference was found in microhardness for conventional and LED cured composite
neither for baseline, and nor for post immersion periods values.
Conclusion: Pepsi cola reduce microhardness of both differently cure composite groups and this reduction in
microhardness was increased with time. The difference in light curing device did not interfere with the softening
effect of Pepsi cola on composite resin.
Key words: Beverage, Pepsi cola, LED, composite microhardness. (J Bagh Coll Dentistry 2010;22(2):12-15).