Purpose: The aim of this study was to examine condition concerning fusion of inorganic material to enamel and porcelain surfaces by means of Nd:YAG laser.
Materials and Methods: Iron oxide was added to dental porcelain material in a range from 0.6 to 5.0% by weight. Slurry was placed on the human enamel and dental porcelain surfaces and Nd:YAG laser was exposed with varying energy and exposure time periods.
Results: Melting of material occurred with the following irradiation condition; 40 W for 4 s for 0.6% iron oxide, 20 W for 2 s for 2.5% and 5% iron oxide. Fusion of the material occurred with specific conditions. However, degeneration or degradation of tooth substrate also was detected with high energy and extended exposure period.
Conclusion: It was possible to fuse an inorganic substance to enamel surface using Nd-YAG laser. Further investigation is required about materials, type of laser, and irradiation condition.

Purpose: To evaluate the effects of different surface treatments on the tensile bond strengths of a resin cement to zirconia ceramics.
Materials and Methods: Zirconia discs (Lava) were fabricated and the surfaces of the specimens were ground with #600-grit SiC paper. Then the specimens were divided into four groups according to the surface treatment: (1) no pretreatment (control); (2) air-abrasion with 110 µm Al₂O₃; (3) laboratory tribochemical silica coating (Rocatec) with 110 µm Al₂O₃ and 30 µm silica modified Al₂O₃; (4) coating the surface (INT coating) with silica-based porcelain (Vintage ZR). Each group was subsequently divided into two subgroups assigned to be silanated using a ceramic primer (RelyX Ceramic Primer) or not. The bonding procedure was then performed using a dual-cure resin cement (RelyX ARC). After 24 h storage in water, the specimens were thermocycled (5-55˚C, 5,000 cycles). The bonding performance was evaluated by the tensile bond strength test. Statistical analyses were performed at the level of p=0.05.
Results: The control groups showed the lowest bond strengths. The silanated groups showed significantly higher bond strengths than the non-silanated groups for each surface condition (p>0.05). The highest bond strength (27.2±6.2 MPa) was provided by the INT coating group with silanization. However, no significant difference was obtained between the INT coating and Rocatec groups after silanization (p>0.05).
Conclusion: With silanization, the INT and tribochemical silica coatings were the most effective in improving the bond strengths of the resin cement to zirconia ceramics.