Effects of surface treatment,hydration and application method on the bond strength of a silorane adhesive and resin system to dentine

Objectives

To evaluate the effects of surface treatment, surface hydration (SH) and application method (AM) on the tensile bond strength of the Silorane Adhesive System (SAS) to dentine.

Methods

Ninety bovine teeth were used. For the control group (n = 10), each dentine surface was treated according to the manufacturer's instructions of the SAS. The remaining teeth were randomly distributed into two groups (n = 40), according to the type of dentine surface treatment (ST)—37% phosphoric acid or Er:YAG Laser prior to the application of the SAS. Each group was further divided into 2 subgroups (n = 20), according to the SH status: dry (D) or wet (W). Each subgroup was further divided into 2 subgroups (n = 10), according to the application method [AM: Active (AC) mode or Passive (PA) mode]. A coat of resin composite (Filtek P90) was applied on the surface. Artificial ageing was performed with a thermo-mechanical cycling machine. The specimens were sectioned into 1 mm × 1 mm × 10 mm sticks and stressed to failure using a universal testing machine. The remaining teeth in each group were used for Scanning Electron Microscopy to examine the fractured area. Data were subjected to a three-way ANOVA, Tukey's test and Dunnet's test (α = 0.05).

Results

The ANOVA showed significant differences for SH and AM, but not for ST. For SH, the results of Tukey's test were (in MPa): D – 14.9(±3.8)^a, W – 17.1(±4.3)^b; and for AM: PA – 14. 9(±4.2)^a, AC – 17.1(±3.9)^b.

Conclusions

Acid etching, when combined with a moist dentine surface and the use of primer agitation, improves the bond strength of the SAS to dentine.

Clinical Significance

According to the results of the present in vitro study, modification of the application protocols for the silorane-based adhesive system may improve its clinical performance.