Porcelain veneer bonding to dentin and the curing performance of plasma-arc light with respect to porcelain thickness.

Plasma and halogen lamp units were used to photo-cure a composite resin for porcelain bonding. Mean shear bond strengths to dentin after light curing through porcelain of 1 and 2 mm thickness ranged from 20 to 27 MPa before and after thermocycling, indicating no significant effects due to porcelain thickness, curing method, or thermocycling, except for plasma curing for 3 s through porcelain of 2 mm thickness that overcame thermocycling. The mean bond strength in this group was significantly lower than both that before thermocycling and that of the porcelain of 1 mm thickness. Knoop hardness values for plasma curing for 3 s through porcelain of 2 mm thickness were significantly lower than the others. These results suggest that plasma light for 3 s is not sufficient to cure composite resin cement through porcelain of 2 mm thickness.