Case 32: Worn All on 4 Prosthesis- Making a new prosthesis

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Case 32: Worn All on 4 Prosthesis- Making a new prosthesis

 Any acrylic hybrid prosthesis has its life as they are subjected to occlusal load and day to day wear. Normally a hybrid prosthesis on an all-on 4 or all on 6 will stay good for a period or 3-5 years. They will wear out over a period of time and requires a new prosthesis or relining the acrylic portion on the existing bar frame.

Here we have a case where the patient had undergone all on 4 in the upper and the lower arch had only 3 implants. Surprisingly they are holding good. We did advise the patient to go in for a malo prostheis with either Zirconia frame and Zirconia crowns or milled frame with PFM crowns, but the patient opted to go in for an acrylic hybrid again.

The sequence involved Removal of the worn prosthesis and a trayless impression with splinting of the impression post with pattern resin and the fit is tried again with a jig trial. Furthere jaw relation and trial is done followed by Final prosthesis torque. As per all on 4 protocols, Any abutment screw on an angulated multi unit abutment should be done at 15 Ncm. if it was a straight multi unit abutment then the torque is 35 ncm.

The sequence of the prosthesis fabrication is as follows in the following images.







 This case was done by me at Parasu Dental Hospital,  Chennai.

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