The primary challenge associated with implant overdentures lies in the occurrence of denture fractures around the attachments. Hence, it is recommended to enhance flexural strength through reinforcement frameworks. This study aimed to assess and compare the prosthetic maintenance of mandibular implant overdentures reinforced with Co-Cr and PEKK frameworks. Twenty-four participants with completely edentulous ridges were selected, and two implants were placed at the mandibular canine areas. After osseointegration period, ball attachments were installed. Participants were randomly assigned into two groups: Group I received a mandibular implant overdenture reinforced with a Co-Cr framework, while Group II received a mandibular implant overdenture reinforced with a PEKK framework. Prosthetic maintenance evaluations were conducted in both groups twelve months post-denture insertion. Categorical data were analyzed, and results were presented as frequency and percentage values. Group II exhibited a significantly higher percentage of cases with screw looseness, denture relining, and tooth separation compared to Group I. Although Group II cases showed a non-significant increase in the percentage of insert wear and retention loss. Within the limitations of this study, the findings suggest that Co-Cr, in contrast to PEKK frameworks, offers a more reliable reinforcement of the implant-retained overdentures.