Objective: To evaluate the contribution of chemical and micromechanical bonding of Fuji II LC (F) and Riva LC (R) by measuring their shear bond strengths to dentin following four different chemical conditioning regimens. Methods: Caries free third molars were mounted in acrylic and their occlusal surfaces reduced to dentin for bonding. Teeth were randomly assigned to eleven different groups (n=15) depending upon surface treatments which were: (A) Smear layer intact (negative control), (B) “Cavity Conditioner” containing 20% polyacrylic acid, (C) 17% EDTA, (D) “Self Conditioner” containing 4-META/HEMA and (E) bonding using Optibond Solo Plus (OBSP) after acid etching with 37% phosphoric acid. Composite Z250 (Z) resin bonded to dentin with OBSP after acid etching served as the positive control. Conditioning agents were used according to manufacturers' instructions. Copper band matrices 5mm in diameter and 2mm in height were affixed to the dentin. After conditioning, Fuji II LC, Riva LC or Z250 were placed in matrices and light-cured for 20 seconds. Specimens were stored for 24 hours in de-ionized water at 37ºC prior to shear testing in an Instron Universal Testing machine at a crosshead speed of 0.05mm/min. Results: Mean shear bond strengths and standard deviations recorded in MPa were as follows: RA 4.97(1.55)DE, RB 3.91(1.53)E, RC 4.11(1.54)E, RD 6.20(0.75)D, RE 15.56(1.75)A, FA 3.64(1.17)E, FB 5.43(2.03)DE, FC 8.08(1.74)C, FD 9.48(1.49)C, FE 12.19(1.50)B and ZE 14.88 (2.87). Data was analyzed with ANOVA and Tukey's HSD. Groups with the same superscripts are statistically similar (p<0.05). Experimental groups were compared to the positive control using Dunnett t tests (p<0.05). Conclusions: Positive control (composite/dentin bond) was stronger than all groups except for Riva LC bonded with OBSP. Bonding RMGIs with OBSP and Self Conditioner contributes more strength through micromechanical bonding than the chemical bond of RMGI to dentin alone.