Leucite-reinforced glass ceramic inlays luted with self-adhesive resin cement: a 2-year in vivo study

Objectives. Aim of the present prospective controlled clinical study was to compare the clinical performances of two different cementation procedures to lute IPS Empress inlays and onlays. Methods. Eighty-three IPS Empress restorations (70 class-II inlays, 13 onlays/47 premolars, 36 molars) were placed in 30 patients (19 females/11 males, mean age = 39 years). Two cementation procedures were tested: group 1: forty-three restorations were luted with a self-adhesive resin cement (RelyX Unicem, RX, 3M ESPE); group 2: forty restorations were luted with an etch-and-rinse multistep adhesive (Syntac Classic, Ivoclar-Vivadent) and Variolink II low (SV, Ivoclar-Vivadent). All restorations were evaluated after 2 weeks (baseline = 1st recall = R1, n = 83), 6 months (R2, n = 83), 1 year (R3, n = 82), and 2 years (R4, n = 82) by two independent blinded calibrated examiners using modified USPHS criteria. Results. From R1 to R4, one failure occurred in the SV group (at R2) due to marginal enamel chipping. After 2 years of clinical service (R4), better marginal and tooth integrity (p < 0.05) was found in group 2 (SV) compared to the use of the self-adhesive cement (RX, group 1), while no differences were found for all remaining investigated criteria (p > 0.05). The absence of enamel in proximal boxes (10% with no enamel and 51% of the restorations with less than 0.5 mm enamel width at the bottom of the proximal box) did not affect marginal performance (p > 0.05). Significance. The self-adhesive resin cement RelyX Unicem showed clinical outcomes similar to a conventional multi-step cementation procedure after 2 years of clinical service for most of the tested criteria. (C) 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.