Prosthesis mounting device and assembly
A prosthesis mounting device and assembly for securing a prosthesis on an implant supported in bone tissue. An appendage or “preppable abutment” is carried by a dental implant and is milled or “prepped” into a shape suitable to accept a dental prosthesis such as a crown or bridge. Alternatively the appendage may be cast using a lost-wax investment molding process in which an appendage model is shaped by adding and sculpting wax onto portions of a calcinable appendage and/or removing material from portions of the appendage before using the model to form a mold. In each case the appendage is formed to include a recess that extends axially upwardly from a bottom end of the appendage and is shaped to fit over an O-ring receiver abutment or “O-ball” of a dental implant.
1. A method for securing a prosthesis on an implant supported in bone tissue, the method including:
installing in a patient's jaw bone an implant having an O-ball abutment and integral nut;
removably supporting on the implant a calcinable appendage comprising calcinable material and having a receptacle shaped to engage and fit closely over the O-ball abutment of the implant and a multi-faceted portion shaped to engage and fit closely around the integral nut of the implant;
sculpting the calcinable appendage into a desired permanent appendage shape by applying sculptable material to the calcinable appendage and shaping the sculptable material, the desired permanent appendage shape being suitable to allow a dental prosthesis to be supported on the permanent appendage after the permanent appendage has been formed;
forming an appendage mold by investing the sculpted appendage in refractory material;
removing the sculpted appendage from the mold;
casting a permanent appendage by providing suitable material in the mold, allowing the material to harden, and removing the refractory material from the hardened permanent appendage;
supporting the cast permanent appendage on the implant;
molding a dental prosthesis to fit on the permanent appendage supported on the implant; and then
supporting the dental prosthesis on the permanent appendage supported on the implant.
2. The method of claim 1 in which the step of sculpting the appendage into a desired dental prosthesis-supporting appendage shape includes applying wax to the appendage and shaping the wax to provide a desired dental prosthesis-supporting appendage shape.
3. The method of claim 2 in which:
the step of sculpting the appendage into a desired dental prosthesis-supporting appendage shape includes adding wax to the desired appendage shape in the shape of a mold access port; and
the investing step includes investing the added wax along with the sculpted appendage.
4. The method of claim 1 in which the step of sculpting the appendage into a desired dental prosthesis-supporting appendage shape includes removing material from portions of the appendage.
5. The method of claim 1 in which the step of removing the sculpted appendage from the mold includes melting the sculpted material and draining it from the mold.
6. The method of claim 1 in which the step of removing the sculpted appendage from the mold includes burning the calcinable material of the appendage from the mold.
7. The method of claim 1 in which the step of casting a permanent appendage includes providing a material comprising zirconium in a mold and then baking the material.
8. The method of claim 1 in which:
the step of removably supporting on the implant a calcinable appendage includes providing a calcinable appendage having a recess that extends upwardly into the appendage from an axial bottom end of the appendage, the recess including an inner wall having a cylindrical portion shaped to fit over the O-ball abutment of the implant and a multi-faceted portion shaped to engage and fit closely around the integral nut of the implant, forming an annular cement retention cavity between the recess wall and an undercut portion of the implant that is defined by a lower hemisphere of the O-ball abutment of the implant; and
the step of supporting the cast permanent appendage on the implant includes cementing the appendage on the implant such that cement is disposed within the cement retention cavity.