@ARTICLE{Majidinia, author = {Sarraf Shirazi, A and Majidinia, S and Hosseinyar, Z and }, title = {Investigating the Effects of LED and QTH Light Cure Devices on Composite Hardness}, volume = {20}, number = {4}, abstract ={BACKGROUND AND OBJECTIVE: Light cured composites allow dentists to begin the process of polymerization on demand. According to the importance of curling on the mechanical properties of composites, the purpose of this meta-analytical study is to compare the effectiveness of light curing LEDs and QTH devices on the hardness of composites. METHODS: In this meta-analysis review articles from the PUBMED, SCOPUS, and ISI databases were analyzed without any limitations in language or time, to compare the hardness of composites after curing with LED and QTH devices .Two analyzes were carried out with out any limitation in time or language, with a radiation intensity of less than 500 and more than 500 mW / cm2. The thickness of the cured composite in both groups was considered to be 2 mm. Non-matched articles with the variables mentioned in the study were deleted. Data were analyzed using the random effects model (α=0.05(. FINDINGS: Using the random effects model, there was no significant difference between the hardness of 2 mm thickness of the composite after curing with LED and QTH at light intensity higher than 500 mW / cm2 (p = 0.43) but there was a significant difference (p=0.000)at an intensity less than 500 mW/Cm2. CONCLUSION: The lightcure LED device was better in terms of its effect on the hardness of composites at below 500 mW / cm2 intensity than QTH, but did not show differences at higth intesity. }, URL = {http://jbums.org/article-1-7245-en.html}, eprint = {http://jbums.org/article-1-7245-en.pdf}, journal = {Journal of Babol University of Medical Sciences}, doi = {10.18869/acadpub.jbums.20.4.42}, year = {2018} }