BackgroundSilicate ceramic bonding is carried out by acid-etching with hydrofluoric acid (HF) followed by an application of silane. By replacing HF with ammonium polyfluoride, contained in the same flask as the silane, the number of steps in this clinical procedure, can be reduced, while maintaining bond strength values, and reducing toxicity. A shear bond test was performed to compare the conventional and the simplified surface treatment techniques.Material and Methods Twenty ceramic samples were fabricated from IPS emax CAD® ceramic (Ivoclar Vivadent) and divided into two groups (G1 and G2) (n=10). The conventional technique was applied to G1 samples, and the simplified technique to G2 samples. A resin cement cylinder was bonded to each sample. Afterwards, samples underwent shear bond strength testing in a universal test machine.Results G1 obtained 26.53±6.33 MPa and G2 23.52±8.41 MPa, without statistically significant differences between the two groups.Conclusions Monobond Etch&Prime appears to obtain equivalent results in terms of bond strength while simplifying the technique. Further investigation is required to corroborate these preliminary findings. Key words:Shear bond strength, surface treatment, bonding to ceramic, hydrofluoric acid, ammonium polyfluoride.

Background As there is no standard method for re-cementing debonded partial ceramic restorations, the aim of this study was to evaluate the use of a non-invasive thermal protocol for cleaning and retreatment, and to study its influence on shear bond strength. Material and Methods Twenty ceramic samples (IPS e.max CAD®) were bonded to composite cement cylinders and underwent a shear bond strength test (G1, n=20). A second group was created (G2, n=20), representing debonded restorations. To simulate debonding, the samples were artificially contaminated with composite cement. After debonding, these underwent a thermal protocol to remove remaining adhesive. After rebonding to the composite cement cylinders, samples underwent the shear bond strength test. Results Median bond strengths for G1 and G2 were 7.28±3.23; 7.06±3.41 MPa, respectively, without significant difference between the groups ( p =0.983). Conclusions Debonded lithium disilicate glass-ceramic restorations should undergo a laboratory cleaning and retreatment protocol before being returned to the clinic for rebonding. Key words: Ceramic, adhesive debonding, shear bond strength, porcelain laminated veneers.