Aim: to evaluate the effect of the novel one step ceramic surface treatment on the retention of lithium disilicate crowns cemented with two different luting approaches (self-etch and self- adhesive resin cements) compared to the conventional surface treatment technique. Materials and methods: 28 extracted molar teeth were prepared to receive full coverage lithium disilicate glass ceramic crowns with lateral projections for pull out test. The crowns were divided into 2 main groups according to the surface treatment applied, Group 1: conventional surface
treatment by hydrofluoric acid followed by silane coupling agent(HF+silane), Group 2: the new self-etching ceramic primer Monobond etch and prime(MEP). Each group was subdivided into
2 subgroups according to cementation protocol: In Subgroup A crowns were bonded using self- etch resin cement (Rely X Ultimate) while in subgroup B, crowns were bonded using self- adhesive resin cements (Rely X U200). Crowns were tested for retention using pull out test until failure occurred. Results: Group 2 showed statistically insignificant higher retention mean value (204.63±35.30 N) than Group 1(196.21±39.76 N), while subgroup A (265.75±49.35 N) showed statistically significant higher retention mean value than subgroup B (135.09±25.71 N). Subgroup 2A (MEP and Rely X Ultimate) had the highest bond strength (267.42 ±40.92 N) followed by 1A (HF+ silane and Rely X Ultimate), 2B (MEP and Rely X U200), 1B(HF+ silane and Rely X U200). Conclusion: Self-etching ceramic primer MEP is strongly recommended to replace conventional surface treatment. Self-etching ceramic primer(MEP) with self-etch resin cement provided the highest bond strength.