¿Es útil utilizar ácido fosfórico tras el grabado con ácido fluorhídrico?Revisión crítica de la literatura

Abstract

The chosen protocol for the adhesive cementation of ceramics with a vitreous matrix includes the conditioning of the ceramic surface with hydrofluoric acid, however, the use of this acid entails toxicity caused by the dissociation of the fluorine ion and the production of insoluble salts on the ceramic surface that can influence in the adhesiveness quality. Currently, several procedures have been proposed to treat these surfaces after the use of acid etching: ultrasound baths for 5 minutes in distilled water, the use of phosphoric acid, the use of a triple air-water spray syringe and the application of neutralizing agents, among others. The main objective of this critical review is to evaluate the scientific evidence that supports the use of phosphoric acid as an alternative to other systems in the cleaning and neutralization of hydrofluoric acid. A bibliographic search was carried out in the main databases (PubMed/MEDLINE, Cochrane Library and EMBASE). Several studies have proposed, like the Gold Standard for cleaning the etched ceramic surface, the use of ultrasound with distilled water for 5 minutes. No significant differences were found when comparing the adhesion values within the utilization of distilled water and phosphoric acid. However, when performing the EDX analysis, some studies do find significant differences and effectiveness regarding the ability to remove the fluoride ion from the ceramic surface when using phosphoric acid, while other studies continue to find traces of the fluoride ion. According to the studies reviewed, no significant differences were found in the bond strength values when comparing the use of phosphoric acid with the ultrasound bath. Regarding the ability of phosphoric acid to remove the fluorine ion, the results are controversial.