Implant placement in edentulous mandible with immediate loading - Provisional Acrylic Fixed Hybrid Conversion Prosthesis

A case I did recently. The lower denture was prepared preoperatively and then converted into an all acrylic fixed hybrid prosthesis. Therefore the name "conversion prosthesis". The ridge was literally knife-edge as can be seen from the image alongside. Follow along on the images below. The images are more or less self explanatory.

• The edentulous ridge
  

• A knife edge ridge. CT Scan
  

• The knife edge ridge exposed.

• The ridge levelled, four implants placed. Note the transosseous fixation of the flap to prevent the excessive redundant tissue left after ridge levelling from riding up and covering the healing abutments. This loose tissue can be quite a nuisance when fabricating the immediate prosthesis as well during later healing.

• Healing abutments in place and flap repositioned and sutured.

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  the denture hollowed out

• The hollowed out denture loaded with bite registration material

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The tissue surface of the hollowed out denture relined with rigid bite registration material at the correct VDO

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The denture slotted in the position of the two distal most cylinders

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A piece of rubber dam placed to prevent the acrylic getting entangled with the sutures. The two distal cylinders in place.

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The distal two cylinders are picked up in cold cure acrylic. The denture is stabilised by the rigid bite registration material and the posterior untouched denture base.

• All four cylinders picked up in acrylic. Note the shortened dental arch (premolar to premolar no cantilevers)
  

• the final conversion prosthesis with screw holes sealed with Fermit
  

• The completed provisional restoration