This study was carried out to evaluate the effect of two different treatment modalities on the abutment teeth supporting partial dentures in class I Kennedy classification cases radiographically. Fourteen patients were selected with missing mandibular molars teeth bilaterally opposed by dentulous maxillary arch. Patients were divided into two groups, each of seven patients. The first group received skeleton removable prosthesis retained by O.T cap attachment, whereas the second group received skeleton partial denture retained by a combination clasp with modified half T gingivally approach clasp arm. Radiographic evaluation was performed using the Digora computerized system. The linear measurement system supplied by the software of the Digora machine was used for recording changes in bone density and marginal bone height distal to the abutments in both groups throughout the study period. The results of this study revealed a statistically significant difference in bone height and density changes between both groups. Those receiving O.T cap attachment- retained partial denture showed decrease in bone density and decrease in marginal bone height distal to the abutments to a degree less than those receiving partial dentures with combination clasp. KEY WORDS: The extra coronal attachment- the combination clasp- Digora computerized radiographic system.