Methods and Materials: Two types of CAD / CAM blocks (Cerasmart, GC; Enamic, Vita Zahnfabrik) were cut into 4mm thick plates and divided into six groups and subjected to the following surface treatment: Group 1: No treatment; Group 2: Group 5: 5% hydrofluoric acid etching (hydrofluoric acid) + Si; and Group 6: SB + Si + flowable composite material (see below); Group 5: 5% hydrofluoric acid etch (hydrofluoric acid) 37% phosphoric acid etching (H 3 PO 4) + Si. The same set of sections were dipped together (n = 3: 3 sandwich sample / group) using a double curable self-adhesive cement for all groups except for slices of group 4 made of photo-curable flowable composite. After storage at 37 ° C for 3 weeks in 0.5% chloramine, the sandwich sample was sliced in a rectangular microdissection and trimmed into dumbbells (1.1 mm in diameter) at the interface. Half of the samples were subjected to micro tensile bond strength (μTBS) test and the other half tested after six months of storage (aging). The linear mixed effect model was used for statistical analysis of surface treatment, material type and aging factors, and their first - order interaction (α = 0.05).

Results: The lowest binding strength was obtained without any surface treatment (group 1), and the highest μTBS was obtained when the surface was roughened by SB or hydrofluoric acid, which was combined with chemical adhesion through Si. When omitting the surface roughening or silanization or both, the loss of the adhesive strength was observed after aging at 6 months.

CONCLUSIONS: Regardless of the surface treatment used, composite materials and polymer permeation of ceramic CAD / CAM modules all exhibit the same adhesive acceptability. The micro-positioning surface is generated by SB or hydrofluoric acid, then chemical adhesion using Si, and the bond strength is mandatory after six months.