Effect of Ti:Sapphire-femtosecond laser on the surface roughness of ceramics

Some of these adult patients have ceramic crowns, to which orthodontists have concerns about bonding brackets. The aim of the present study was to evaluate the effect of a Ti:Sapphire femtosecond (fs) laser (Integra-C-3.5, Quantronix, NY) on the surface roughness of two ceramic surfaces (feldspathic and IPS Empress e-Max) and to compare results with those of two other lasers (Er:YAG and Nd:YAG) and conventional techniques, i.e., sandblasting (50 µm) and hydrofluoric (HF) acid.

Ceramic discs were fabricated (n = 150) and divided into two groups, each of which was then divided into five subgroups prepared with Ti:Sapphire fs, Nd:YAG, or Er:YAG lasers, sandblasting, or HF acid (n = 15). The surface roughness of the ceramic discs was evaluated using a profilometer (Mitotoyo Surf Test SJ 201 P/M; Mitutoyo Corp, Japan) before and after each surface treatment. Three traces were recorded for each specimen at three different locations in each direction, providing nine measurements per sample, which were then averaged to obtain the surface roughness value. Data were analyzed using the Wilcoxon signed-rank test (P < <0.05), two-way ANOVA, and Tukey's HSD test (P < 0.05). Additional samples were prepared for each group and evaluated using atomic force microscopy (AFM; NTEGRA Solaris, NTMDT, Russia).

No significant difference was found between the feldspathic and IPS Empress e-Max ceramics. The Ti:Sapphire fs laser was associated with the highest mean roughness value. AFM images of the ceramic surfaces treated confirmed that the fs-laser-treated surfaces had the highest degree of irregularity.

Within the limitations of this in vitro study, the Ti:Sapphire fs laser yielded the highest surface roughness and could be an alternative ceramic surface treatment to increase bond strength.