Ablation Effects of Er: YAG Laser Irradiation Using Newly Designed Contact Probes on Dentin Surfaces
Confocal Laser Microscopy Observation and Scanning Electron Microscopy Observation
2002 Volume 13 Issue 2 Pages 62-71
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2002 Volume 13 Issue 2 Pages 62-71
Recently, many studies have been performed on the Er: YAG laser to expand its clinical use.This investigation aimed at evaluating the effects of Er: YAG laser irradiation using newly designed contactprobes on human dentin surfaces. Dentin disks were prepared from tooth crowns of human molars. An Er: YAG laser (MEY-1, J. Morita, Kyoto, Japan) was irradiated at 30mJ through two kinds of newly designedcontact probes, and a conventional flat end-type contact probe. The newly designed probes, which had a sharpend, were used for experimental groups (Group C, n=10, Group J, n=10), and a flat end contact probe (GroupA, n=10) was used as a control. Touching the end of the contact probes with the surfaces of dentin disks, onelaser pulse was delivered under water spray cooling. After the laser irradiation, samples were stained withrhodamine 123, and observed by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM), to evaluate the laser-irradiated surfaces three-dimensionally. Results obtained were as follows.
1. In every dentin disk, a cavity was created by the laser shot. The cavities were significantly deeper inGroups C and J than in Group A (P<0.0001, ANOVA). On the other hand, cavities of Group A had asignificantly larger diameter compared with those of Groups C and J (P<0.0001, ANOVA).
2. SEM observation showed no debris on the cavity surfaces in any group. However, melted dentin surfaceswere observed only in the experimental groups.
