Fig 4.1 (A) Final abutment inserted on implant and (B) ceramic crown fixed over it, using luting cement.
Fig 4.2 (A) Implant before prosthetic loading (mirror image); (B) screw-retained ceramic crown fixed over the implant; (C) screw hole closed using tooth-coloured composite.
Fig 4.3 If available bone volume and density allow placing longer and adequate diameter implants with adequate amount of primary stability and bone implant contact percentage, a multiple unit bridge can be delivered over a few implants.
(Courtesy: Nobel Biocare)
Fig 4.4 (A and B) Four implants are inserted in the posterior maxilla to support a four-unit ceramic prosthesis.
Fig 4.5 (A) Only two implants are inserted to support a four-unit ceramic bridge, (B) in lower anterior region.
Implant prosthetic options for completely edentulous patients
For completely edentulous patients, the dental implant is the only option to support a full-arch, fixed prosthesis or to retain loose dentures. Beside the conventional, full-arch, implant-supported prosthesis, advancement in implant component engineering has brought multiple graft-less options (‘all on 4’/‘all on 6’ techniques) for edentulous patients, to deliver fast and fixed prostheses or implants retained overdentures.
1. Implant-supported removable prosthesis (implant overdenture). Depending on the dentist’s preference and various clinical parameters, usually two types of ‘implant overdentures’ are delivered to patients.
a. Ball-retained overdentures.
Two to four implants are inserted in the anterior mandible while 4–6 implants are inserted in the anterior maxilla; ball abutments or ‘locator abutments’ are inserted over the implants. The ‘O’ rings or metal housings are fitted into the tissue surface of the denture and they get locked over the ball abutments or locator abutments, when the dentures are seated in the mouth. These implants provide adequate retention to the dentures (< ?xml:namespace prefix = "mbp" />Fig 4.6
b. Bar-retained overdentures.
A metal bar is fabricated in the laboratory and fixed over the implants. Special header clips are fixed into the tissue surface of the denture, which gets locked over the bar, when the denture is seated in the mouth. The bar provides adequate retention and stability to the denture (Fig 4.7
2. Implant-supported fixed prosthesis. There are multiple options for the implant-supported fixed prosthesis. Usually a number of implants are inserted in the jawbone and the multiple unit ceramic or hybrid prosthesis is fixed over these implants. The following are different options for the full-arch implant-supported fixed prosthesis:
a. Screw or cement-retained ceramic prosthesis.
After thorough diagnosis and treatment planning, several implants (with the best possible dimensions for each implant) are inserted and placed at the best
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