IPS-Empress inlays luted with a self-adhesive resin-cement after two years

Methods: 83 IPS Empress restorations (70 Class-II inlays, 13 onlays / 47 premolars, 36 molars) were placed in 30 patients (19 female / 11 male, mean age 39.4 years). All restorations were inserted under rubber dam. 43 inlays/onlays were luted with a self-adhesive resin cement (RelyX Unicem [RX], 3M Espe, Seefeld, Germany). A total-etch multi-step adhesive (Syntac) was used with Variolink II low ([SV] Ivoclar-Vivadent, Schaan, Principality of Liechtenstein) and served as control (n=40). The restorations were evaluated after two weeks (baseline=1st recall=R1), after six months (R2) after one year (R3) and after two years (R4) by two calibrated examiners using modified USPHS criteria.

Results: From R1 to R4, one failure occured in the SV group (R2) due to marginal enamel chipping. After two years of clinical service, SV revealed significantly better results regarding marginal integrity and integrity tooth (Mann-Whitney U-test, p<0.05). No statistically significant differences were computed between SV and RX for the remaining criteria (Mann-Whitney U-test, 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 residual enamel width in the proximal box) did not have any influence on marginal performance of the inlays and onlays (Mann-Whitney U-test, p>0.05).

Conclusions: The self-adhesive resin composite RelyX Unicem showed acceptable clinical behavior after two years of clinical service.

Supported by 3M Espe, Seefeld, Germany.