Effect of Different Irradiation Times on the Occlusion of Dentinal Tubules When Using a Nd -YAG Laser - An <i>in Vitro</i> SEM Study
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2015-01-01 |
| Journal | Open Journal of Stomatology |
| Authors | Xiaoyu Guo, Jinhua Yu, Roger J. Smales, Chen Huifen, Hai-Yan Si |
| Institutions | Nanjing Medical University, The University of Adelaide |
| Citations | 2 |
Abstract
Section titled āAbstractāObjective: To evaluate the effect of different irradiation times on the occlusion of dentinal tubules when using Nd:YAG laser. Background data: Dentin hypersensitivity is a frequent problem that has limited treatment success despite many chemical and physical therapies. Methods: Four coronal dentin disks 2 mm thick were cut with a low-speed diamond saw from four freshly extracted intact first molars. The coronal dentin surface of each disk was divided into four regions, each approximately 2 mm Ć 3 mm. The dentin surfaces were treated with 27% EDTA then the four regions irradiated separately in a randomized pattern with a Nd:YAG laser (120 mJ, 5 Hz), using irradiation times of 0 s, 20 s, 40 s and 60 s, representing laser energies of 0 J/cm2, 200 J/cm2, 400 J/cm2 and 600 J/cm2, respectively. SEM photomicro-graphs were taken at 1500Ć and 3000Ć to calculate the dentinal tubule orifice occlusion rates and to measure the tubule diameters, respectively. Results: For the laser irradiation times of 0 s, 20 s, 40 s and 60 s, the corresponding dentinal tubule occlusion rates were 2.05 (SD 0.29)%, 10.01 (1.71)%, 23.58 (2.51)% and 90.23 (2.24)%, respectively; and the tubule diameters were 4.18 (0.32) Ī¼m, 3.46 (0.24) Ī¼m, 1.69 (0.32) Ī¼m and 0.12 (0.02) Ī¼m, respectively. There were significant differences among all groups for both measured variables (p ā¤ 0.005). Conclusions: Within the limitations of this in Vitro study, when using a Nd:YAG laser at 120 mJ and 5 Hz, an irradiation time of 60 s achieved the best sealing of the coronal dentinal tubule orifices.