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Title LED Curing Lights Provide A Greater Composite Micro-hardness Than QTH Curing Light Systems
Clinical Question In receiving a resin composite restoration, will LED curing light systems as compared to QTH curing light systems provide a greater composite microhardness?
Clinical Bottom Line For in vitro teeth receiving a resin composite restoration, LED curing lights provide a greater composite micro-hardness than halogen curing light systems. This is supported by a RCT in which LED lights outperformed the halogen curing lights.
Best Evidence (you may view more info by clicking on the PubMed ID link)
PubMed ID Author / Year Patient Group Study type
(level of evidence)
#1) 20178217Zhu /200990 light cured resin composites In vitro
Key resultsSpecimens cured with the Mini LED AutoFocus light provided higher KHNs than those photo activated with the LEDemetron I light and Optilux 401 light. There was no statistically significant difference in KHNs between the LEDemetron I group and the Optilux 401 group. The mean Knoop micro-hardness values decreased significantly as the curing tip distance increased. Fifteen minutes after light cure, effective hardness percent values (> 80%) were achieved in a few experimental groups. A linear correlation was found between the logarithm of the power density and the hardness percent values.
#2) 22077680Cassoni/20113 experimental groups evaluated at 24 hours and 6 months In vitro
Key resultsAll evaluated factors showed significant differences (p < 0.05). After 24 hrs there were no differences within the experimental groups. KHN at 0 mm was significantly higher than 2 mm. After 6 months, there was an increase of micro-hardness values for all groups, being the ones activated by LED higher than the ones activated by QTH.
Evidence Search 1) curing[All Fields] AND ("light"[MeSH Terms] OR "light"[All Fields] OR "lights"[All Fields])2) (Curing[All Fields] AND ("light"[MeSH Terms] OR "light"[All Fields] OR "lights"[All Fields])) AND Randomized Controlled Trial[ptyp]3)"Curing Lights, Dental"[Mesh] AND "Composite Resins"[Mesh] AND Comparative Study[ptyp]
Comments on
The Evidence
The Zhu article reported 90 resin composite specimens cured with three different curing lights. Although there was a relatively large sample size, there is no evidence to suggest that the experimenters were blinded to the results indicating a relatively weak evidence. The Cassoni article the specimens were divided into 3 groups and evaluated in depth after 24 hours and 6 months of storage. Although the sample size was not known, this randomized controlled trial provides good evidence that the use of LED curing lights provides a more effective depth of cure as well as a higher micro-hardness number.
Applicability The use of LED curing lights should be considered in middle aged patients receiving resin composite restorations over halogen curing lights as evidenced by the greater micro-harness achieved. Although the trials done in these studies may not be representative of an actual clinical setting, the use of an LED curing light should be considered the best option available as demonstrated by their higher micro-hardness.
Specialty/Discipline (General Dentistry) (Pediatric Dentistry) (Restorative Dentistry)
Keywords LED curing lights, QTH curing lights
ID# 2250
Date of submission: 04/23/2012spacer
E-mail bealka@livemail.uthscsa.edu
Author Neil Bealka
Co-author(s) e-mail
Faculty mentor/Co-author Suman Challa, BDS, MS
Faculty mentor/Co-author e-mail challas@uthscsa.edu
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