Aim: This two-year follow-up study was aimed to evaluate declining crestal bone levels around dental implants in patients rehabilitated with mandibular implant-supported overdentures. A three-dimensional advanced radiographic tool, cone beam computed tomography (CBCT), was utilized as radiographic aid in this study.Materials & Methods: A total of 15 patients wearing mandibular implants supported overdentures were studied for two years. Randomization and strict inclusion/exclusion criteria were followed during study execution. Complete dentures were fabricated with standard methods, which were later anchored by a bilateral implant in the mandibular jaw. Bone loss at all four surfaces in all studied implants was estimated by the cone beam computed tomography (CBCT) technique. These assessments were done at postoperative follow-up periods of six, 12, 18, and 24 months. Duly signed and informed consent was obtained from all participating patients.Statistical Analysis and Results: The statistical analysis was completed by the software IBM Corp. Released 2013. IBM SPSS Statistics for Windows, Version 22.0. Armonk, NY: IBM Corp. All relevant data was entered into it to be analyzed with suitable statistical tests. Out of all 15 studied patients, 11 were male, and four were female. P-value was very significant for the age range 35-40 years (0.01). In all instances, the lingual surface showed minimum, while the distal surface showed maximum bone loss when seen at all postoperative phases. Grossly, the mean bone loss ranged between 0.14-0.45. P-value was highly significant for the measurements made at the lingual and distal sides of implants (for both B and D positions). A comparison of both study groups by one-way ANOVA confirmed a highly significant p-value for estimations done between the groups (0.001).Conclusion: Within the limitations of the study, the authors confirmed that crestal bone levels showed a clear decreasing pattern in the postoperative phases. Since these deleterious processes can compromise long-term prosthesis success, operators should consider all these facts while planning to implant an overdenture prosthesis in the lower jaw.