Objectives: the aim of the study is to evaluate radiographically the crestal bone height change around all on four implant supported hybrid prosthesis
Material & Methods: Fourteen patients were selected from Ain shams Outpatient. clinics having completetly edentulous maxilla opposed by full dentulous mandible and they were properly diagnosed for implant placement. Implant sites were planned virtually and a 3D printed surgical guide was made. The implant had been installed in proper position and angulations using the surgical guide. Patients were randomly divided into 2 groups, Group I; received a hybrid prosthesis on delayed loaded four implants, Group II; received a hybrid prosthesis on immediately loaded four implants. Postoperative CBCT was performed at time of pickup (base line), 6 and 12 months
Results: Although the data obtained revealed that group I showed lower level of crestal bone height change compared to group II, statistical analysis of the data revealed insignificant difference during the one year follow up period.
Conclusion: in all on four implants delayed loading hybrid prosthesis shows no significant difference regarding bone resorption around implants than in all on four implants immediately loaded hybrid prosthesis