The aim of this study was to assess the effect of RPI direct retainer designs in mandibular Kennedy's class I removable partial denture cases, on the periodontal conditions of their abutment teeth.
Materials and methods: A total of 10 systemically healthy Patients were selected with mandibular Kennedy class I with symmetrical healthy periodontium at first premolar abutments split mouth mandibular class I removable partial denture designs RPI, I-bar (Rest, proximal plate and I bar) in one side (side A) and a modified RPI clasp assembly (Rest, proximal plate connected by lingual bracing arm to the rest and I Bar) in other side (side B) were constructed. Clinical evaluation(gingival index, pocket depth and clinical attachment loss) and recording of GCF levels of Interlukin1ß IL1 –β using ELISA were carried out for all patients at base line (time of denture insertion), 3 months and 6 months after denture insertion at mandibular free end saddle abutments.
Results: A statistically significant increase in the mean IL-1ß levels after 3 months with further significant increase after 6 months was recorded in both sides (P ≤ 0.05) further, side B showed a statistically increased IL-β levels compared to side A. Regarding clinical parameters, side B showed a statistical significant increase at 6 months compared to side A regarding PD with no significant difference between the 2 sides at 3 months ,as for CAL and GI, although side B showed an increased readings in 6 months and 3 months compared to side A, a non significant difference was recorded between the 2 sides, as well, a non significant change in GI and CAL was recorded in both sides over the study period .
Conclusion: within the limitation of our study, the modified RPI clasp induced increasing of proinflammatory cytokines IL- 1ß levels in GCF compared conventional RPI clasp assembly. Both Clasp designs have an effect on periodontal health of free end saddle's partial denture abutments.