Er:YAG Laser Debonding of Lithium Disilicate Laminate Veneers: Effect of Laser Power Settings and Veneer Thickness on The Debonding Time and Pulpal Temperature.

Er:YAG laser is a non-destructive tool for debonding of laminate veneers. This study investigated the effect of different laser powers on the pulp temperature and the time required to perform the debonding of lithium disilicate laminate veneers with different thicknesses. The labial enamel of 48 maxillary central incisors was flattened and polished. The teeth were restored with flat lithium disilicate ceramic veneers (4.0 mm×6.0 mm) with one of two different thicknesses (0.5 and 1.0 mm). Veneer debonding was performed with an Er:YAG laser with a wavelength of 2940 nm, pulse duration of 100 μm (VSP mode), 10 Hz, and one of the three laser power settings: 1.5 W (150 mJ), 3.0 W (300 mJ). and 5.4 W (540 mJ) (n=8). Veneer detachment time and intra-pulp temperature change (ΔT) were measured. Statistical analysis was performed using the two-way ANOVA and Bonferroni's post hoc test (α=0.05). The correlation between debonding time and temperature change was calculated using Pearson's correlation. The longest time was recorded to remove the 1.0-mm veneer at 1.5 W (<0.05) and the shortest time was recorded when deboning the 0.5 mm veneer with 5.4 W (<0.05). ΔT decreased significantly with increasing laser power. A low correlation was found between time and ΔT (R=0.113). Laser power and veneer thickness are important factors for veneer debonding; thinner veneers are removed faster. When debonding thick veneers, 5.4W laser power is more efficient and causes fewer changes to the pulp temperature.