Background and Aim: Screw loosening is one of the most common clinical dilemmas seen in the post operative phases of implant therapy. Screw loosening can lead to ultimate failure of the prosthesis thus entire treatment. Several factors are discussed by different researchers which are responsible for screw loosening. Therefore, this in vitro study was conducted to comprehensively assess the effect of different types of implant abutment with varying loading stresses on early screw loosening. Materials & Methods: This study was conducted in the department of Prosthodontics wherein total sixty implant abutment samples were included. Group 1 consisted of twenty standard types abutment. Group 2 consisted castable abutment. Group 3 consisted of CAD-CAM assisted implant abutment. A customized rectangular metal jig was fabricated in which implant fixture fits comfortably. Abutments were tightened over the implants with maximum of 30 Ncm. Dynamic stresses were applied independently on each sample assembly and unscrewing torques was noted carefully. P value less than 0.05 was considered significant (p< 0.05). Statistical Analysis and Results: Statistical analysis was completed by using statistical software Mean torque value (Unscrewing Torques before Cyclic Loading) for group 1, 2 and 3 was 19.37, 17.82 and 17.43 respectively. Mean torque value (Unscrewing Torques after Cyclic Loading) for group 1, 2 and 3 was 18.17, 16.92 and 16.55 respectively. The measured standard deviation was 0.381, 0.637 and 0.032 for group 1, 2 and 3 respectively. P value was highly significant for group 1. The comparison among the 3 study groups using one-way ANOVA showed highly significant level of significance. Two sample t- test assessments of mean score and standard deviation in three groups showed highly imperative values. Conclusion: Within the limitations of the study authors confirmed that there was not any significant different in the initial screw loosening stresses with various abutment systems. All the three experienced implant abutment systems showed insignificant change in screw loosening stresses after undergoing cyclic loading.