Adhesion of RelyX Unicem Aplicap on RelyX Fiber Post

Objectives: The purpose of this in vitro investigation was to evaluate the influence of different surface treatments of the new RelyX™ Fiber Post (RXFP, 3M ESPE) on the adhesion of RelyX™ Unicem Aplicap™ self adhesive universal resin cement (RXU, 3M ESPE).

Materials and methods: The conical part of RXFP (Size 3) was used. The surface was either left untreated or silane treated by using a) RelyX™ Ceramic Primer (RXCP, 3M ESPE) or b) Monobond-S (MON, ivoclar vivadent) or silicatized and silanized by using the Rocatec™ Pre/Plus system (ROC, 3M ESPE) and RXCP or acid etched with Etching gel (ETCH, 3M ESPE). After applying RXU to the surface (discs: d = 6,0 mm, h = 4,0 mm), the cement was light-cured for 40 seconds (LC) by using Elipar Trilight (3M ESPE). For comparison adhesion was also tested if RXU was used in the dark cure mode (DC) with untreated or silanized posts. Specimens were stored for one hour at 36 °C / > 95 % rel. humidity and for 23 hours in water at 36 °C. Finally a pull-off test was made using an universal testing-machine (crosshead speed 1 mm/min). Six specimens were tested for each surface coverage.

Results: The following table summarizes the mean adhesion values of RXU to the post. Surface treatment does not have a significant influence on the adhesion (LC mode: p = 0,086; DC mode: p = 0,764).

Conclusions: Bond strength of RXU self adhesive universal cement to the fiberpost surface is high and independent of any of the surface treatments tested.