Mechanical properties of dentin after Er:YAG laser irradiation measured by nanoindentation
HE Zheng-di
ZHOU Li
Masayuki Otsuki
Junji Tagami
CHEN Ling-ling
RUAN Shuang-chen
Abstract：AIM:To evaluate the nanohardness and Young’s modulus of dentin after Er:YAG laser irradia-tion using a nano-indentation tester.METHODS:1 5 dentin disks obtained from extracted human third molars were prepared and exposed to a single pulse laser irradiation at 80 mJ/pulse.5 specimens were observed for the morphology of laser-ablated dentin surface using a SEM.The remaining 1 0 specimens were crosscut through the expose center of the lased point.Among the 1 0,5 were observed under SEMfor the subsurface-lased dentin,5 lased and 5 sound den-tin specimens were measured for nanohardness and Young’s modulus.RESULTS:The irradiated dentin surface was irregular,scaly or flaky.Laser irradiation denatured subsurface layer about 1 5 μm deep was present.The nanohardness and Young’s modulus of the Er:YAG laser denatured dentin were significantly lower than those of sound dentin (P<0.05).CONCLUSION:Er:YAG laser irradiation can affect the nanohardness and Young’s modulus of dentin subsurface.
Keywords：Er:YAG laserdentinnanoindentationnanohardnessYoung’s modulus
Publication Date：2016-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：5( 602-606 )