title: Active and Passive Application of the Phosphoric Acid on the Bond Strength of Lithium Disilicate.
abstract: The objective of this study was to evaluate the effect of passive or active phosphoric acid (PA) application after hydrofluoric acid (HA) treatment on the microshear bond strength of lithium disilicate. Thirty ceramic discs were made with IPS Emax 2 (10 mm thick and 10 mm diameter). The specimens were divided into 3 groups, A: 9.6% HA application; AF: 9.6% HA application + cleaning with 37% PA in passive mode and AFF: 9.6% HA application + cleaning with 37% PA in active mode. For the microshear test, four tygons (0.9 mm diameter and 0.2 mm high) were filled with resin cement (RelyX Ultimate) and placed on the ceramic disks. After testing, the fracture modes were examined under scanning electron microscopy. Data were analyzed by one-way ANOVA and Tukey's post test (α=0.05). The bond strength values were significantly higher in Group AFF (11.0±2.5 MPa) compared with group A (8.1±2.6 MPa) (p<0.002). AF group was not statistically different (9.4±2.5 MPa) from Group A. It was concluded that the active application of 37% PA after 9.6% HA increases the microshear bond strength values between the resin cement and lithium disilicate ceramic.
authors.affiliation: Department of Dentistry, Universidad Hispano Guarani, Asunción, Paraguay.
authors.forename: Tatiana Cardona
authors.initials: TC
authors.lastname: Giraldo
authors.affiliation: Department of Dentistry, Universidad Hispano Guarani, Asunción, Paraguay.
authors.forename: Vanessa Roldan
authors.initials: VR
authors.lastname: Villada
authors.affiliation: Department of Dentistry, Universidad Hispano Guarani, Asunción, Paraguay.
authors.forename: Mauricio Peña
authors.initials: MP
authors.lastname: Castillo
authors.affiliation: Department of Dentistry, Universidade Estadual de Ponta Grossa, Ponta Grossa, PR, Brazil.
authors.forename: Osnara Maria Mongruel
authors.initials: OM
authors.lastname: Gomes
authors.affiliation: Department of Dentistry, Universidade Estadual de Ponta Grossa, Ponta Grossa, PR, Brazil.
authors.forename: Bruna Fortes
authors.initials: BF
authors.lastname: Bittencourt
authors.affiliation: Department of Dentistry, Universidade Estadual de Ponta Grossa, Ponta Grossa, PR, Brazil.
authors.forename: John Alexis
authors.initials: JA
authors.lastname: Dominguez
mesh_terms: D000134:Acid Etching, Dental; D001840:Dental Bonding; D003776:Dental Porcelain / Q000737:chemistry*; D010756:Phosphoric Acids / Q000737:chemistry*
chemical_list: D010756:Phosphoric Acids; C493120:lithia disilicate; D003776:Dental Porcelain; C030242:phosphoric acid