Effect of Er,Cr: YSGG laser debonding treatment on the optical properties and surface roughness of ceramic laminate veneers: An in vitro study.

Purpose: The objective of this study was to evaluate the effect of (Er,Cr: YSGG) laser debonding treatment on optical properties and surface roughness of veneers made of different ceramic materials.

Materials and methods: Thirty bovine incisors were prepared to receive laminate veneers and divided into three groups (n = 10) according to ceramic material where group (E): IPS e.max CAD, group (S): Vita Suprinity, and group (C): Celtra Duo. Blocks were sectioned into 0.5 mm thickness plates and cemented on the labial surface of incisors using resin cement. The Er,Cr: YSGG laser was applied to each specimen at 4.5 W and 25 Hz for group E and at 6 W and 25 Hz for groups S and C. Color change (△E₀₀), translucency parameter (TP) and surface roughness in µm (Ra) values were measured and calculated before and after laser treatment. Data were analyzed using two-way mixed model ANOVA at a significance level of p < 0.05.

Results: The highest mean △E₀₀ value was recorded in group E (1.35 ± 0.09) followed by group S (1.08 ± 0.16) and then group C (0.93 ± 0.10) with a significant difference between them (p < 0.001). All groups exceeded the perceptibility threshold but remained below the acceptability threshold. No statistically significant difference was found in TP except for group E (p = 0.019). Ra values after laser debonding showed significantly higher values than before laser treatment in all three groups (p < 0.001).

Conclusion: Er,Cr: YSGG laser can be safely used for debonding ceramic veneers without altering the optical properties but it does increase the roughness of debonded ceramic restorations.