A Comparative Study of the Biological and Prosthetic Complications of CAD/CAM Zirconia and Conventional Cast Implant Supported Hybrid Prostheses

Document Type : Original Article


Department of Prosthodontics, Faculty of Dentistry, Cairo University.


Aim: The Target of this work was to study the different Prosthetic and Biological Complications of two different techniques of framework construction; the Casting Metal Technology and the Zirconia CAD/CAM Technology in screw-retained prostheses.
Materials and Methods: In this study, twelve patients with fully edentulous maxillae had a total of seventy-two implants inserted. Six implants were inserted in each patient's lateral incisor, first premolar, and first molar regions. Patients were randomly split into two equal groups, Group I received cast metal frameworks, and Group II received zirconium CAD/CAM frameworks. The passivity of fit was assessed for both groups using the one screw test at the time of definitive prosthetic delivery. Prosthetic and biological complications were assessed after three and six months. Moreover, calculations, analyses, and comparisons between both groups were done regarding the quantity and length of visits performed in each group.
Results: Regarding Prosthetic Complications, statistical analysis revealed a higher statistically significant percentage of screw looseness in Group I in comparison with Group II (P-value < 0.05) after 3-month and insignificant difference after 6 months. As for biological complications, Statistical Analysis at three and six months follow-up of implant failure/looseness and Peri-implantitis revealed a higher percentage in Group I than Group II but with a statistically insignificant difference (P-value > 0.05).
Conclusion: CAD/CAM restorations yielded fewer prosthetic and biological complications, less time, and number of clinical visits than the Conventional Casting group. CAD/CAM restorations should thus be considered a viable alternative to cast implant frameworks restorations.


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