Bond strength between a high-performance thermoplastic and a veneering resin

Abstract

Statement of problem: High-performance thermoplastics have been adopted as framework materials. However, their bond strength to an esthetic veneering material is unclear.

Purpose: The purpose of this in vitro study was to test the tensile bond strength (TBS) between an aryl-ketone polymer (Ultaire AKP) and veneering resins.

Material and methods: AKP substrates (N=324) were prepared, airborne-particle abraded (Al₂O₃, 50 μm, 0.2 MPa), and divided into 9 groups (n=36) with different bonding systems (visio.link, Adhese Universal, All-Bond Universal, CLEARFIL UNIVERSAL BOND, G-Premio BOND, iBOND Universal, ONE COAT 7 UNIVERSAL, Scotchbond Universal) and without a bonding system as a control. Each group was further divided for opaquer (n=18). Further subdivision followed according to flowable or paste veneering resin (n=9). Specimens were stored in distilled water for 24 hours at 37 °C and thermocycled (×5000, 5/55 °C). TBS was measured and analyzed with the Kolmogorov-Smirnov test and 3-way ANOVA with partial eta squared (η_P²), followed by the Kruskal-Wallis and Mann-Whitney-U tests. Relative frequency of failure types was analyzed with the Chi²-test and a Ciba-Geigy table.

Results: The highest impact on TBS was exerted by the adhesive (η_P²=0.458, P<.001), followed by opaquer (η_P²=0.288, P<.001). The binary combination of the 3 variables was significant for opaquer coupled with adhesive (η_P²=0.173, P<.001). Visio.link showed the highest TBS followed by All-Bond Universal and Scotchbond Universal. Opaquer increased the TBS for all adhesives except for visio.link. Without adhesive, opaquer obtained comparable TBS to visio.link. Flowable veneering resin showed higher TBS than paste resin.

Conclusions: The application of opaquer increased TBS for all universal adhesives. Using opaquer and flowable veneering resin is beneficial for bonding to Ultaire AKP.