Document Type : Research Paper


1 Health ministry, Nenevah

2 Department of Pedodontics, Orthodontic and Preventive Dentistry, College of Dentistry, University of Mosul, Iraq


Aims: To assess and report the microhardness incidence in fissure system of the human dental enamel next Er,Cr:YSGG laser and Diode laser applications in order to examine anti-cariogenic impact and to compare the obtained results between the two laser types. Materials and Methods: Forty extracted impacted lower third molars teeth used in the experiment that should have an obvious occlusal fissure. Intact lower third molar were collected, which were free from caries. Teeth roots separated from crowns ,then the crowns were separated  bucco-lingually  into two equal parts which were applied in 4 test groups included  control group without any treatment, acid group only immersed in demineralizing solution, Diode laser group in which samples subjected to Diode laser (at wavelength 980nm, power 5 watt, mode P3, the time was 30 second) then immersed in demineralizing solution PH 4.4 for 96 hr., and Er,Cr:YSGG laser group in which samples  subjected to Er,Cr:YSGG laser (wave length 2780nm, pulse energy 20 Hz with pulse mode (H-mode), time 10 second) then immersed in demineralizing solution pH 4.4 for 96 hr. Results: The mean microhardness was significantly different from each other at p≤ 0.01. And Er,Cr:YSGG laser had mean surface microhardness significantly higher than other groups then Diode laser group. Conclusions: Both types of lasers increased microhardness of enamel at fissure area, and Er,Cr:YSGG had better effect than Diode laser..


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