Ali, Samer MostafaEl Talawy, Dina Bahgat2020-09-042020-09-042019-100070-9484http://repository.msa.edu.eg/xmlui/handle/123456789/3742Purpose: The aim of this study was to evaluate clinical and radiographic outcomes of polyetheretherketone (PEEK) hybrid prosthesis used for “All on four” rehabilitation of edentulous maxilla. Materials and methods: Six patients with atrophied edentulous maxillary ridges were managed by 4 implants according to the “All on four” protocol using computer guided surgery and flapless surgical approach. The existing maxillary dentures were placed immediately after modifications on the same day. After 6 months, the definite prosthesis consisted of screw retained milled BioHPP framework bonded to acrylic resin teeth and denture base. The prosthesis restored lost teeth, hard and soft tissues (hybrid fixed prosthesis). Plaque and gingival index, probing depth, implant mobility and bone loss (measured by standardized periapical radiographs) were evaluated after prosthesis delivery (T0), six months (T6) and 12 months (T12) after delivery. Results: Two implants failed in one patient resulting in 91.7% survival rate. Plaque index increased with time. No difference in gingival index, pocket depth, implant stability, and vertical bone loss between observation times was noted. Posterior implant showed higher plaque scores and pocket depth than anterior implants after 6 and 12 months and no significant difference in all other parameters between anterior and posterior implants was noted. Conclusion: Within the limitation of this study, PEEK hybrid prosthesis bonded to acrylic resin teeth and denture base can be used successfully to rehabilitate patients with atrophic maxilla according to “All on four” concept as it was associated with favourable clinical and radiographic outcomes after one yearen-USPOLY- ETHERETHERKETONE (PEEK)HYBRID PROSTHESISArticle