In Vitro Evaluation of the Performance of Self-Adhesive Resin Cements on Zirconia

TL;DR

This study tested how well self-adhesive resin cements bond to zirconia, finding that using a zirconia primer improves performance, though thermocycling reduces bond strength.

Contribution

The study introduces a new evaluation of MDP and calcium silicate-based cements on zirconia with and without primer under thermocycling.

Findings

Bond strength was highest with TheraCem, followed by Clearfil SA Luting and Rely X U200.

Zirconia primer significantly improved bond strength across all cement types.

Thermocycling reduced shear bond strength in all groups, with mixed failure modes observed.

Abstract

This study evaluated the bond strength of self-adhesive resin cement (SARC) containing 10-methacryloyloxydecyl dihydrogen phosphate (MDP) and calcium silicate, with and without zirconia primer, before and after thermocycling. Sintered zirconia specimens (n = 180) were sequentially polished, sandblasted, and bonded with TheraCem (TC), Clearfil SA Luting (SA), or Rely X U200 (RU), with and without Z-Prime Plus primer. Specimens were stored in water at 37 °C or subjected to 10,000 thermocycles (5–55 °C). Shear bond strength (SBS), failure modes, fracture surfaces, flexural strength, and Vickers hardness were assessed. Bonding performance was governed by material-specific interactions rather than a complex three-factor interplay between resin cement type, primer application, and thermocycling. SBS followed the order TC > SA > RU and was significantly higher with primer application. Thermocycling significantly reduced SBS in all groups. Premature failure occurred in the RU and SA groups. Mixed failure was predominant across all conditions. The flexural strength and Vickers hardness were highest in the RU group, followed by the TC and SA groups, with RU maintaining significantly higher hardness even after thermocycling. Overall, SARCs containing MDP and calcium silicate demonstrated favorable bonding performance, which was further enhanced by zirconia primer application.

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