Abstract

CAPARROSO PEREZ, Carlos et al. IN VITRO EVALUATION OF THE EFFECT OF HYDROFLUORIC ACID ONCENTRATION AND APPLICATION TIME ON ADHESION TO LITHIUM DISILICATE. Rev Fac Odontol Univ Antioq [online]. 2014, vol.26, n.1, pp.62-75. ISSN 0121-246X.

INTRODUCTION: as a ceramic restorative material, lithium disilicate provides higher resistance to ceramic materials, excellent optical characteristics, and the ability to be bonded to tooth substrate by hydrofluoric acid etching. The purpose of this study was to perform in vitro assessment of the effect of 4.6 and 9.5% hydrofluoric acid at 20, 40 and 60 s on the surface of lithium disilicate during the processes of adherence to a resinous substrate. METHODS: 6 IPS e-max^® Press porcelain cubes and 6 Filtek Z250^® resin cubes were made. The ceramic cubes were subjected to surface treatment obtaining 6 groups: control group and groups 2 and 3 were treated with 4.6% hydrofluoric acid during 20, 40 and 60 seconds respectively, and groups 4, 5 and 6 were treated with 9.5% hydrofluoric acid at 20, 40 and 60 s respectively. Porcelain cubes were cemented with the resin ones with self-adhesive resin cement and bars of 1 x 1 x 18 mm were produced, obtaining 20 samples in each group. Adhesive strength was measured. RESULTS: adhesive strength values expressed in MPa (SD) were as follows: G1 = 26.69 (± 7.99), G2 = 23.93 (± 7.99), G3 = 20.90 (± 7.91), G4 = 17.56 (± 6.61), G5 = 16.30 (± 11.68), G6 = 18.78 (± 10.22), with significant differences between group 1 and groups 4-5. CONCLUSIONS: 4.6% hydrofluoric acid produced better adhesive averages compared with the 9.6% concentrations. The group with 4.6% concentration during 20 s offered the best results.

Keywords : ceramics; dental porcelain; lithium disilicate; hydrofluoric acid.

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