Influence of different surface treatments on the shear bond strength of a methacrylate resin composite repaired with silorane-based resin

Resumo

When repairs are needed in restorations made with
methacrylate-based resin composites, the clinician still has doubts
whether it is possible to use a silorane-based material and which is
the best procedure. Objective: To evaluate the shear bond strength
between a methacrylate-based resin composite and a silorane-based
material using different surface treatments. Material and methods:
Eighty flat bases made with methacrylate resin composite (Filtek
Z350 XT) were prepared (n = 8). The bases were stored into water
at 37°C for one week. Ten groups were evaluated: G1 (control – no
repair); G2 (surface grinding, washing, drying, adhesive and repair
with Filtek Z350 XT); G3 (surface grinding, washing, drying, adhesive
and repair with silorane – Filtek P90); G4 (surface grinding, washing,
drying, adhesive, silane and repair with Filtek Z350 XT); G5 (surface
grinding, washing, drying, application of silane, adhesive and repair
with silorane – Filtek P90). All groups were kept at 37°C for 24 h in either water (G1 to G5) or ethanol (G6 to G10). The results were
analyzed with one-way ANOVA and Tukey test (α = 0.05). Results:
There were significant differences between groups (p < 0.001). Only
repairs made with silane and Z350 XT (G4 = 46.2 ± 12.9; G9 =
48.1 ± 16.3) resulted in values similar to controls (G1 = 59.2 ±
15.8; G6 = 62.3 ± 15.9) (p = 0.33). The smallest value occured
when the repair was performed with silane and silorane-based based
and stored into ethanol (G10 = 29.9 ± 12.4). The storage media
had little influence on the results. Conclusion: The silorane-based
resin composite was not effective for repair of the methacrylatebased material.