Shanghai Journal of Stomatology ›› 2025, Vol. 34 ›› Issue (3): 233-236.doi: 10.19439/j.sjos.2025.03.002

• Original Articles • Previous Articles     Next Articles

Effect of Er:YAG laser combined with NaClO on the removal of root canal smear layer and dentin microhardness

Bai Xue1, Wang Xiao2   

  1. 1. Department of Stomatology, Chifeng University Affiliated Hospital. Chifeng 024000;
    2. Department of Stomatology, Chifeng Cancer Hospital. Chifeng 024000, Inner Mongolia Autonomous Region, China
  • Received:2024-10-29 Revised:2024-12-18 Online:2025-06-25 Published:2025-06-24

Abstract: PURPOSE: To evaluate the effects of Er:YAG laser combined with NaClO on the removal of root canal taint layer, calcium hydroxide clearance and dentin microhardness. METHODS: A total of 318 single-rooted extracted teeth collected from March 2021 to January 2024 were selected, the 13 mm root was taken and mechanically prepared and randomly divided into three groups, with 106 teeth in each group. The control group was rinsed with NaClO, the experimental group 1 was rinsed with NaClO combined with ultrasonic washing, and the experimental group 2 was treated with Er:YAG laser on the basis of NaClO. The removal of the smear layer was observed under electron microscope, and the microhardness of dentin post-treatment was assessed using a microhardness tester. RESULTS: The clearance rate of calcium hydroxide in experimental group 2 was significantly higher than that in experimental group 1 and control group, and the stain layer scores of crown formula 1/3, root middle 1/3 and root tip 1/3 were significantly lower than those in the other 2 groups(P<0.05). There was no significant difference between the initial and final microhardness of the three groups(P>0.05). CONCLUSIONS: Er: YAG laser combined with NaClO can effectively enhance the removal effect of stain layer in root canal therapy, and has little effect on dentin microhardness.

Key words: Er:YAG Laser, Ultrasonic washing, Sodium hypochlorite, Root canal smear layer removal rate, Dentin microhardness

CLC Number: