To Compare the changes of retention between three different implant analog angulations of OT equator smart box attachment for a two implant-retained mandibular overdenture when subjected to chewing cycles of 75 000 and 150 000 equivalent to 6 months and 12 months). Methodology: A completely edentulous mandibular stone model was scanned using an extra-oral lab scanner to produce an STL file. The STL file was then used to virtually plan for two-implant analogs in the canine area bilaterally. Three groups were planned; In group I (straight); two implants analog were installed parallel to each other with a zero-degree difference in implant analog angulations, in group II (Buccal inclination) the left implant analog socket (A) was straight, and right implant analog socket (B) hole was installed with a 25degrees buccal angulation and group III (Distally inclined) the left implant analog socket (A) straight and right implant analog socket (B) with a 25degrees distal angulation. Simulation of the oral mucosa was carried out by preparing a 2mm cutback on the residual alveolar ridge extending between the retromolar pads bilaterally. The overdenture was then designed and a space for the attachments housing of the three different angulations were designed to be included in the fitting surface of the overdenture to facilitate the pickup procedure. Nine models and nine overdentures were 3D-printed to be used in the present study. For all groups, the implants were installed in the prepared sockets by using self-cure acrylic resin, and then the smart box OT equator attachment was screwed to the implant analogs and then picked up in the fitting surface of the denture. The geometric center was identified and then the initial retention (baseline values) was recorded for all groups using the universal testing machine. Then all groups were subjected to 75000 cycles and 150000 cycles using the chewing simulator and retention values were recorded after each cycle. The mean retention of both implants in each group was then tabulated and statistically analyzed. Shapiro Wilk and Kolmogorov test was used for normality exploration. One Way ANOVA was used for multiple comparisons followed by Tukey`s Post Hoc test. Repetitive One-Way ANOVA for different intervals followed by Tukey`s Post Hoc test. Paired -t-test was used to measure changes in retention before and after the different cycles. The significant level (P-value) was determined to be significant as P-value > 0.05. Results: There was a statistically significant decrease in retention between the three groups after being subjected to 75 000 cycles (equivalent to 6 months) and 150 000(equivalent to 12 months). After 75000 Cycles (equivalent 6 months) the greatest decrease in retention was recorded for group I (straight) -13.32 ±0.27N, followed by -9.96±0.98N, and the least decrease in retention was reported by group III 1.54±0.59 N (P=0.0001). While after 150 000 cycles (equivalent to 12 months) group I showed the greatest decrease in retention -12.28 ±0.31N, followed by group III -8.44±0.26N, and the least decrease in retention was reported by group II -3.31±0.26N (P=0.0001).