Chairside Overdenture Conversion
We will demonstrate locator to overdenture attachment chairside (step-by-step) .
Patient must be diagnosed with terminal dentition.
Bridge removed revealing the non-restorable dentition.
Extractions and Alveloplasty completed.
Palatal tissue isolated with suture.
Implants placed. All implants must be torqued >35Ncm to achieve predictable results.
Distal implants placed at 30 Degree angle to avoid sinus.
This correction of angulation is made by the Multi-unit abutment. Multi-unit abutments should be placed by the implant surgeon.
Graft placed in all sites.
Healing abutment placed on #10 site. This implant will not be engaged for the temporary. We will plan to use this 5th implant on the final prosthesis.
Sutured using 4-0 PGA mattress and single interrupted sutures and 4-0 Silk sutures for reinforcement.
Place bite registration on intaglio of denture and seat.
This technique will mark the location of the abutments so you can drill holes into the denture.
Access holes fabricated.
Temporary cylinders placed via hand torque.
Please make sure all temporary cylinders have retention grooves installed. Some manufactures only carry smooth cylinders.
Place a rubber dam or any other type of barrier to protect the multi-unit abutment from the acrylic. The acrylic tends to be less viscous initially so it must not contact the multi-unit abutments, otherwise removal will be very difficult!
Make sure to only engage the temporary cylinders.
Check for clearance on the temporary cylinders!
They must not touch denture and they must be clear of occlusion.
I will usually trim the temporary cylinders in the mouth with a high speed handpiece.
Place cotton pellets in the cylinders to block out acrylic in the next step. Fill cotton to the rim.
Fill a monojet syringe with medium viscosity pink acrylic. Cut the tip of the syringe about 4mm for easier flow.
Using the monojet syringe, fill each space around all metal cylinders with the pink acrylic. Work quickly as the arcylic will begin to cure immediately.
Fill to rim and have the patient bite down in maximum intercuspation AND/OR Centric relation. (MI should be equal to CR).
Allow curing time of 10mins.
Remove cotton pellets and reverse torque all cylinders.
Remove prosthesis and spend the next 30-60mins refining the temporary.
Fill in any voids around each with temp cylinder with acrylic using salt and pepper technique.
Remove palate and smooth/polish all edges.
Remove palate, buccal flange and smooth/polish all edges.
Hand torque all screws with prosthesis in place. Hand torque in star pattern to seat evenly.
Should fit passively-- verify seating with radiographs.
Place cotton pellets and temporary material of choice.
Adjust occlusion as needed.