The influence of adhesive systems on bond strength between FRP post and packable composite resin : acomparative study

Abstract EN

Background: The ainrof this in vitro study was conducted to evaluate and compare the bond strength between the -.

packabie composite core (Filtek P60) and the fiber reinforced plastic (FRP) posts (Postec Plus, Ivoclar) which were treated with different adhesive system by using pull out test.

Materials and methods: Sixty FRP posts were seated on the custom made aluminum mold leaving 3mm of post exposed, the post specimens were then randomly divided into six groups (n=10), according to materials used as post surface treatments:G: (A) 37% wf phosphoric acid etching gel only; G: (B) 37% wt phosphoric acid etching gel + Silane coupling agents (Monobond- S); G: (C) 37% wt phosphoric acid etching gel+ Silane coupling agents (Monobond- S) + Total etch adhesives bonding agent (ExciTE); G: (D) 37% wt phosphoric acid etching gel+ Total etch adhesives bonding agent (ExciTE); G: (E) 37% wt phosphoric acid etching gel+ Silane coupling agents (Monobond- S) + Self-etching adhesives bonding agent (AdheSE); G: (F) 37% wt phosphoric acid etching gel+ Self-etching adhesives bonding agent (AdheSE).

After that a cylindrical shaped transparent plastic matrix was then used as a mold for Core buiid ups that was fitted on the elevation of aluminum mold, so that the composite, Filtek P60, can be packed into the matrix in one increment (bulk technique).

After curing and removing the cylinder plastic matrix from the mold, a further irradiation of 60 seconds of composite was carried out from all sides.

The specimen was stored in an incubator at 37C° for one week, at 100% relative humidity.

Testing was done by the Universal testing machine (WP 300) applying pulling out force until the core was separated from the post.

Results: The data were statistically analyzed using Analysis of variance test (ANOVA) and student-t test revealed that treating the post surfaces with Self-etching adhesive system only, produce the highest bond strength values between the packabie composite core material and the FRP posts with high significant difference While, the post surfaces which were treated with phosphoric acid only produce the lowest bond strength values with high significant difference.

Also the examination of the bond surfaces by lens with 20X magnification power showed that only adhesive bond failures occurred between FRP post and packabie composite core.

Conclusions: There is no chemical bond between the packabie composite core and the FRP posts.

Treating the post surfaces with Self-etching adhesive system only, produce the highest bond strength values between the packabie composite core material and the FRP posts followed by combination of silane solution and self-etching adhesive system, combination of silane solution and total etch adhesives bonding agent, total etch adhesives bonding agent only, Silane coupling agents in a decreasing manner.