The aim of this study was to compare the retention of two different forms of clasps in mandibular distal extension prosthesis, which were; the Conventional casted metal clasps & the Tooth-colored acrylic resin clasps "Acetal resin". Materials & Methods: For the rationale of this clinical investigation, fifteen patients were selected from the Outpatient Clinic of the Prosthodontic Department, Faculty of Oral and Dental medicine, Cairo University in accordance with certain criteria. Every patient got a skeleton parial denture that was constructed in a conventional manner. A hole was made in the middle of the lingual plate during fabrication of the framework; A Retention Measuring-Aided Device was made to allow attachment of the digital Forcemeter to this hole for measuring retention. Then, the metal clasp was removed and replaced by acetal resin clasp and the same procedures of measuring retention were performed in the same manner. Retention of the two clasp types was measured four times (at time of insertion, one month, two months and three months, respectively), by the aid of a prefabricated device (The Retention Measuring-Aided Device) for precise reproducible measurement. Results: There was a statistically significant difference (P ≤ 0.05) in the mean Forcemeter measurements from base line to one month. Later, from one month to 2 months and from 2 months to 3 months; there was a statistically insignificant difference (P ≥ 0.05) in the mean Forcemeter measurements. Conclusions and recommendations: Using Tooth-colored dental clasps would not compromise the retention of removable partial denture and can help to enhance the esthetics of removable partial dentures.

Statement of problem:Patient perspectives on the treatment options for maxillary edentulism, which debate include fixed or removable implant-supported prostheses, may help eliminate current uncertainty as to the best choice of treatment plan.Purpose: This study intended to evaluate the impact of implant number placed in fully edentulous maxilla on the clinical as well as the radiographic outcomes of implant-supported maxillary overdentures with locator attachments over two years of investigation.