Bonding Durability of RMGI to Lithium Disilicate With Surface Treatment

Objectives: Both resin cement and resin-modified glass ionomer (RMGI) cement are commonly used for ceramic or metal oxide crown cementation. However, the optimal surface treatment conditions of the prosthetic restoration material with RMGI cement are unclear. This study was designed to evaluate the effect of different surface treatments on the bonding durability of RMGI luting cements to lithium disilicate (LDS) restorative material.
Methods: Two RMGI luting cements, FujiCEM Evolve (FCE, GC) and RelyX Luting Plus Automix (RLP, Solventum) were selected. The surface of LDS (e.max CAD, Ivoclar) sections was polished with #2000 SiC paper. The specimens were divided into three groups: no treatment (NT), hydrofluoric acid treatment (HF), and silane primer treatment (SP). For HF group, 9.5% Porcelain Etchant (BISCO) was applied to the surface for 20 seconds and rinsed for 10 seconds. For SP group, the same procedure used for HF was followed by application of G-Multi PRIMER (GC). The bonding area was defined with a punched sticker (3 mm diameter, 100 μm thickness), and stainless-steel rod was cemented with RMGI luting cements. Each group was divided into two subgroups (N=8): one group stored in water at 37°C for 24 hours (24h), and for the other group the same procedure used for 24h was followed by thermocycling (5-55°C, 30 seconds dwell time) for 10000 cycles (TC). Tensile bond strength (TBS) test was performed at 1 mm/min. Data were statistically analyzed (Kruskal-Wallis and Steel-Dwass test).
Results: Mean (SD) values of TBS are presented in the table. At 24 hours, RLP NT showed lower TBS than other conditions. FCE SP and RLP NT showed no significant decrease in TBS after thermocycling.
Conclusions: FCE with silane primer treatment showed superior bonding durability to lithium disilicate. As an RMGI luting cement, FCE is a suitable choice for lithium disilicate prosthetic restoration in clinical situations.