Effect of Nd:YAG Laser with/without Graphite Coating on Bonding of Lithium Disilicate Glass-Ceramic to Human Dentin

Figure 2

Representative scanning electron microscopy images of the fractured glass-ceramic side of specimens that have been stressed to failure under tension. At high magnification (2,000×) lithium disilicate crystallites created by hydrofluoric acid etching could be seen after the resin cement was dislodged from the bonded interface. (a) Control (2,000X). The lithium disilicate crystallites created by hydrofluoric acid etching. (b) Nd:YAG laser + Sil group: greater roughness can be seen compared to the control group, and it is related to the laser application. (c) Sil + Nd:YAG laser group: the lithium disilicates crystallites created by the laser application. (d) Graphite + Sil + Nd:YAG laser group: cluster-like lithium disilicates crystallites formed by the increased absorbance of the laser caused by the presence of the graphite. (e) Graphite + Nd:YAG laser + Sil group: demonstrating a great amount of deep scratches showing a great loss of the structure of the ceramic and thus did not improve the bond strength.

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