1.Ten implant analogs were secured in five epoxy resin casts perpendicular to the plane of cast in right first molar and left first molar region and implant abutments were screwed
2.100 Metal copings with a loop on the occlusal surface were fabricated using nickel chromium (Ni–Cr) alloy were cemented.
3.Samples are divide in ( 5) group each group of 20abutment
A. group no 1: abutment no surface modification has been done.
B. group no 2:polishing or abrading the implant abutment with a rotary instrument
C. group no 3: airborne-particle abrasion aluminum oxide.
D. group no 4: air borne particle abrasion plus alloy primer.
E. group no 5: etching with CO2 laser
4.metal coping fabricated and cemented with different luting cement
A. RMGI resin-modified glass ionomer,
B.ZOE zinc oxide eugenol,
C.GI glass ionomer,
D.ZP zinc phosphate,
E. PC polycarboxylate,
5. Samples were tested for tensile bond strength using a universal testing machine at a crosshead speed of .5 mm/min.