RESUMEN
The present work was carried out to evaluate the effect of occlusal reactive distal extension removable partial denture on the underlying supporting structures, clinically, cytologically and histopathologically. The subjects of this study were divided into two groups Group [A]: Includes patients with Cobalt-chromium conventional partial denture with PRI clasp system design. group [B]:Includes patients with same design as those of Group [A] but the introduction of a resilient Supersoft layer between acrylic artificial teeth and rigid denture base [occlusal reactive partial denture]. Each patient was examined clinically for plaque index, gingival index, tooth mobility denture bearing area, before and after 3 months of denture use for both groups Cytological study for denture bearing area were made before and after 3 months of denture use Histopathological study was done for patients to show any mucosal alteration under dentures. The results obtained showed that although occlusal reactive partial denture showed good retention stability comfort as well as better function. No apparent increase in abutment tooth mobility, less feeling of denture movement during function and non-function tooth contact, were observed, yet, this denture also showed leaching out of some artificial teeth increased plaque and gingival indices and more inflammatory response in denture-bearing. While, on the other hand conventional partial dentures showed least changes in plaque accumulation and gingival and mucosal inflammation. From this study, one can conclude the following:1-Conventional removable partial denture showed less gingival mucosal inflammation and plaque accumulation than occlusal reactive partial denture which showed increased plaque index and gingival, inflammation index 2- Mobility of the abutment teeth decreased in occlusal reactive partial denture than in conventional denture 3-Cytological and histopathological that conventional removable partial denture preserved and stimulated the under supporting oral mucosa than occlusal reactive partial denture.4-Occlusal reactive partial denture recommended if there are maintenance and extensive care