Objective: To evaluate the microshear bond strength (μSBS) of resin cement to a lithium disilicate
Keywords: bond strength, lithium disilicate glass ceramic, self-etching primer, surface treatment
glass ceramic conditioned with different surface treatment procedures.
Methods: Crystallised slices of lithium disilicate glass ceramic were randomly divided into
five groups (n = 10) according to different surface treatment procedures: the no surface treatment
(NT) group was untreated; the hydrofluoric acid (HF) group was conditioned with 4.5%
HF; the silane (S) group was conditioned with a silane coupling agent; the hydrofluoric acid
and silane (HFS) group was conditioned with HF followed by the silane coupling agent; and
the Monobond Etch & Prime (MEP) (Ivoclar Vivadent, Schaan, Liechtenstein) group was
conditioned with the one-step self-etching primer MEP. Resin cement was applied to the ceramic
surfaces and irradiated. A μSBS test was performed. Failure analysis, surface roughness
tests, surface topography examination and elemental analysis were also conducted. The data
were analysed with a one-way analysis of variance (ANOVA) and Tukey honestly significant
difference test (P < 0.05).
Results: The MEP group resulted in comparable μSBS to the HFS group (16.9 ± 4.3 MPa and
16.0 ± 2.2 MPa, respectively), but a significantly higher μSBS than the NT (1.0 ± 0.9 MPa), HF
(8.9 ± 3.9 MPa) and S (12.6 ± 2.5 MPa) groups. Adhesive failure was mainly observed in the
NT and HF groups, while the S, HFS and MEP groups demonstrated the most mixed failure.
Though micrographs revealed a roughened surface in the HF group, no significant difference
was found with any other groups.
Conclusion: Within the limitations of this study, it can be concluded that the μSBS of resin
cement to lithium disilicate glass ceramic etched with MEP is as efficient as that treated with
HF and silane.