Effect Of Temporary Cements On The Bond Strength Of Ceramic Inlay. The Push-Out Test Evaluation M. Calabrese*, L. Graiff, S. Guzzonato, P.N. Mason (Dept. Of Restorative Dentistry, Dental School, University Of Padova, Italy) The purpose of this in vitro study was to evaluate the shear bond strengths (SBS) when indirect restorations were bonded to dentin following the placement of eugenol-containing or eugenol-free temporary restorations. The push-out test (Haller 1991, modified in Padova University 1997, IADR Abstr 194-1997) for this investigation was used. This test offers the possibility to simulate polymerization stress and luting process like in a cavity. The conically modified design was utilized to evaluate dentin bond strengths of ceramic inlays (Cerana – Nordiska Dental) luted with Scotchbond 1 DBA (3M) and Relyx ARC dual-curing composite luting cement (3M).   Thirty freshly extracted human molars were used. For each tooth a standardized tapered cavity (5° cone) using the Cerana diamond bur (size L) was prepared.   The teeth were randomly divided in 5 groups (6 teeth each):   Group 1 The impression of the cavity with polyvinylsiloxane (Imprint II 3M) was taken; a temporary restoration with Iso-Temp (3M) was luted with eugenol-containing cement (Temp-Bond Kerr) for 5 days; the cavity was cleaned with pumice slurry, etched with 37% phosphoric acid gel for 30 sec., rinsed, dried and treated with Scotchbond 1. The ceramic inlay was seated with Relyx ARC, and light cured for 120 sec., than resin excess was removed.   Group 2 Like group 1 but eugenol-free temporary cement (Temp-Bond NE Kerr) was used.   Group 3 After preparation each cavity was treated using the dual boning technique: etched with 37% phosphoric acid gel for 30 sec., rinsed, dried, treated with Scotchbond 1, light cured for 20 sec. The enamel margins was finished with a diamond bur (20 micron). Steps as group 1 was than followed (Temp-Bond Kerr).   Group 4 Like group 3, but eugenol-free temporary cement (Temp-Bond NE Kerr) was used.   Group 5 (control group) After preparation each cavity was treated with 37% phosphoric acid gel for 30 sec., rinsed, dried, treated with Scotchbond 1, and the ceramic inlay was luted with Relyx ARC.   Each tooth was mounted in acrylic resin and sectioned orizontally to obtain two slices of two 2 mm thick. The inlay were loaded until extrusion from dentin disks by means of an Erichsen testing machine (model 476) at crosshead of 0.5 mm/min and the ESBS were so recorded.   The results in MPa were:     Group 1 Group 2 Group 3 Group 4 Group 5 Mean 7.71 11.65 12.07 17.41 18.13 St D 1.81 2.88 3.38 4.27 4.31   The ANOVA test showed statistical significant difference (p=0.01) among group 4>3>1 and 2>1.   The results suggest that in the indirect restorations the dual application of the DBA (dual bonding technique) and the use of an eugenol-free provisional cement increase in bond strength values of a dual-curing composite luting cement.