Effect of Water-Cooled Nd:YAG Laser on Dentinal Tubule Occlusion In Vitro.
OBJECTIVE
The objective of this study was to investigate the effect of a new water-cooled Nd:YAG laser on dentinal tubule occlusion.


BACKGROUND
The effect of water-cooled Nd:YAG laser on dentinal tubule occlusion has not been reported.


METHODS
Acid-etched dentin samples were randomly divided into three groups: (1) dentin control, (2) dentin treated by Nd:YAG laser, (3) dentin treated by water-cooled Nd:YAG laser. After laser irradiation, half of the samples were immersed in a 6 wt% citric acid (pH 1.5) solution for 1 min to evaluate the acid resistance. The morphologies of dentin surfaces were characterized by scanning electron microscopy. The number and diameters of the open dentinal tubules were analyzed by one-way and two-way analyses of variance.


RESULTS
Both the Nd:YAG laser and water-cooled Nd:YAG laser melted the superficial layer of dentin, which caused dentinal tubule occlusion in most areas and diameter reduction of the rest open tubules. Microcracks on the dentin surface were only observed in the Nd:YAG laser group. The tubule occlusion induced by the two lasers showed a good acid resistance.


CONCLUSIONS
The effect of water-cooled Nd:YAG laser on dentinal tubule occlusion is similar to that of the Nd:YAG laser. The dentinal tubule occlusion induced by the two lasers could resist acid challenge to some extent.
1 State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University , Chengdu, China .|2 Department of Periodontology, West China Hospital of Stomatology, Sichuan University , Chengdu, China .
Shimeng
S
Xiao
1 State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University , Chengdu, China .
Kunneng
K
Liang
1 State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University , Chengdu, China .
Hongling
H
Liu
1 State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University , Chengdu, China .|2 Department of Periodontology, West China Hospital of Stomatology, Sichuan University , Chengdu, China .
Manling
M
Zhang
1 State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University , Chengdu, China .|2 Department of Periodontology, West China Hospital of Stomatology, Sichuan University , Chengdu, China .
Heng
H
Yang
1 State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University , Chengdu, China .|2 Department of Periodontology, West China Hospital of Stomatology, Sichuan University , Chengdu, China .
Shujuan
S
Guo
1 State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University , Chengdu, China .|2 Department of Periodontology, West China Hospital of Stomatology, Sichuan University , Chengdu, China .
Yi
Y
Ding
D000704:Analysis of Variance; D017679:Cryotherapy / Q000379:methods*; D003766:Dental Occlusion; D003804:Dentin / Q000528:radiation effects*; D003807:Dentin Sensitivity / Q000628:therapy; D006801:Humans; D066298:In Vitro Techniques; D053844:Lasers, Solid-State / Q000627:therapeutic use*; D008855:Microscopy, Electron, Scanning / Q000379:methods; D008963:Molar / Q000528:radiation effects*; D015999:Multivariate Analysis; D014867:Water / Q000008:administration & dosage
D014867:Water
Nd:YAG laser; acid-resistance; dentin damage; dentin hypersensitivity; dentinal tubule occlusion; water-cooled Nd:YAG laser