A Correlation Study between different Implant Diameters and Cantilever Lengths on the Marginal Bone Loss of Implant Supported Maxillary Prostheses: A Randomized Controlled Trial

Document Type : Original Article


Prosthodontic Department, Faculty of Dentistry, Cairo University.



Objectives: To report a correlation between the different implant diameter and different cantilever length regarding bone height changes in implant supported maxillary prosthesis.
Materials and methods: Sixteen patients were recruited to receive six implants in the edentulous maxilla. Patients were randomized using sealed envelopes into two groups: Group I received small diameter and Group II with standard diameter. Patients were similarly randomized into sub-groups; Groups IA, IB, IIA and IIB. In Groups IA, IIA, implants were placed with an anterior-posterior AP implant spread to the cantilevers lengths at a ratio of 1:3 while in Group IB, IIB implants were placed at a ratio of 1:2. Cone Beam Computed Tomography (CBCT) was performed at the day of prosthesis delivery, after 4, 8 and 24 month follow up to measure the marginal bone height changes. Spearman`s correlation coefficient was used to correlate between bone height and different implant diameters and cantilever lengths. The significance level was set at P ≤ 0.05.
Results: A weak positive insignificant correlation was found between the different cantilever length and the small and standard implant diameter.
Conclusion: Both the standard and small implant diameter with different cantilever length showed marginal bone height changes within the physiologic limit for implant supported maxillary prosthesis.


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