Simulated Generalized Wear of Luting Cements using PVS Impression Technique

Objectives: A new resin modified glass ionomer (RMGI) luting cement, FujiCEM Evolve (FE) [GC, Tokyo, Japan], has recently been developed. The purpose of this laboratory investigation was to examine simulated generalized wear of this material and compare to RelyX Luting Plus (RP) [3M Oral Care, St. Paul, MN USA].
Methods: Two RMGI luting cements were used in this laboratory study: FujiCEM Evolve (FE) and RelyX Luting Plus (RP). Twenty wear specimens of each of the two luting cements were prepared for simulated generalized wear testing. Stainless-steel fixtures for generalized wear testing were machined with a cylindrical cavity 4.5 mm in diameter and 4 mm in depth. The cements were subjected to a wear challenge of 400,000 cycles in a Leinfelder-Suzuki (Alabama) wear simulation device. Simulated wear was generated using a flat-ended stainless-steel antagonist. Wear testing was performed in a water slurry of polymethyl methacrylate beads. Prior to, and after wear simulation, the surfaces of the specimens were impressed with a poly-vinyl siloxane (PVS) impression material to replicate the surfaces. Simulated generalized wear was determined on the replicated surfaces using a Proscan 2100 noncontact profilometer in conjunction with Proscan and AnSur 3D software. An independent t-test was used for statistical comparisons of both volume loss and mean facet depth (α=0.05).
Results: Volume loss of wear facets was 0.792 mm³ for FE and 1.391 mm³ for RP. Mean facet depth was 55.3 µm for FE and 94.4 µm for RP. Volume loss and mean facet depth of FE were significantly lower (p<0.05) than those of RP.
Conclusions: The results of this study suggest that a newly developed RMGI cement has higher wear resistance when compared to a currently available RMGI cement. The PVS impression technique for RGMI cements was an excellent method for determination of wear for materials sensitive to desiccation.