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Lithium Disilicate glass, an all-ceramic system.Furthermore, lithium disilicate ceramics can be used as a dental repair material, bone repair and filling material, and biological implant material due to their high strength, good biocompatibility, translucency, and attractiveness[4]Consequently, this filler agent lith- ium disilicate is more resistant than feldspathic ceramic4; therefore, it is the material of choice for esthetic treatments with or without a framework.5,6 However, lithium disilicate remains sensitive to acid etching, which can alter the morphology of the ce- ramic and increase its capacity to bond with resin cements.The objective of this study was to evalu- ate the effect different HF concentrations and ap- plication times, with and without an additional etching step with 37% phosphoric acid (H3PO4), on the surface roughness of a ceramic reinforced by lithium disilicate and also on the strength of the bond formed between the ceramic and self-adhesive resin cement.It is one of the most aesthetically pleasing options, porcelain can be layered on it, creating incredible translucency and a very realistic looking tooth that matches with other natural teeth.Lithium disilicate is a filler agent of acid-etchable ceramics, and 60% to 65% of its composition includes lithium oxide (Li2O) crystals.

Lithium Disilicate glass, an all-ceramic system. It is one of the most aesthetically pleasing options, porcelain can be layered on it, creating incredible translucency and a very realistic looking tooth that matches with other natural teeth.Lithium disilicate is a filler agent of acid-etchable ceramics, and 60% to 65% of its composition includes lithium oxide (Li2O) crystals. Consequently, this filler agent lith- ium disilicate is more resistant than feldspathic ceramic4; therefore, it is the material of choice for esthetic treatments with or without a framework.5,6 However, lithium disilicate remains sensitive to acid etching, which can alter the morphology of the ce- ramic and increase its capacity to bond with resin cements. Etching with hydrofluoric acid (HF) at different concentrations and with different application times .

The 10 groups of prepared lithium disilicate disks (n = 10 per group) were treated as follows. The disks in group 1 remained untreated, thus serving as the con- trol group. In groups 5-20, 5-40, and 5-60, the surfaces were etched with 5% HF for 20, 40, and 60 seconds, respectively. In groups 10-20, 10-40, and 10-60, the surfaces were etched with 10% HF for 20, 40, and 60 seconds, respectively. In groups 10-20P, 10-40P, and 10-60P, the surfaces were etched with 10% HF for 20, 40, and 60 seconds, respectively, followed by treatment with H3PO4 for 5 sec.

The objective of this study was to evalu- ate the effect different HF concentrations and ap- plication times, with and without an additional etching step with 37% phosphoric acid (H3PO4), on the surface roughness of a ceramic reinforced by lithium disilicate and also on the strength of the bond formed between the ceramic and self-adhesive resin cement.

Surface treatment is essential for microshear bond strength between lithium disilicate ceramics and self- adhesive cement and for creating roughness of the lith- ium disilicate ceramic. However, acid concentration and exposure time are important factors in surface treat- ment. The 10% HF acid concentration and exposure time from 20 to 40 seconds showed the best results.

Lithium disilicate ceramics offer several advantages:They have excellent mechanical properties and a tooth-like appearance, making them attractive for dental restorations [1]. These ceramics can be prepared with high strength and high translucency, making them suitable for dental restoration [2]. Additionally, modified ion-exchange technology can be used to enhance the biological capacity of lithium disilicate ceramics, promoting multi-reparative functions of gingival fibroblasts and improving their mechanical properties [3]. Furthermore, lithium disilicate ceramics can be used as a dental repair material, bone repair and filling material, and biological implant material due to their high strength, good biocompatibility, translucency, and attractiveness[4]