Method for producing a crown for an implant abutment
A method of producing a crown for a custom implant abutment is carried out as follows. The method begins by preparing a patient's existing dental structures, viz., positioning a dental implant in the patient's mouth. Using a scanner device and associated modeling software, a first 3D model is obtained of a sufficiently large portion of an implant abutment to be attached to the implant. This scan is performed extra-orally. Preferably, the sufficiently large portion is that portion of the abutment bounded by a margin curve. After the implant abutment is attached to the implant (intra-orally), the scanner is used to obtain a second 3D model of the implant abutment attached to the implant (i.e., an intra-oral scan). Using the modeling software, the first 3D model is then aligned to the second 3D model. Thereafter, a boundary curve on the first 3D model is identified. Using the boundary curve to trim the first 3D model, the system then produces a third 3D model. Using the boundary curve, the third 3D model and the second 3D model, the system then creates a fourth 3D model, which is a model of a virtual dental item. Using a computer-assisted milling machine, the model of the virtual dental item is then used to produce an actual crown, which is then attached to the implant to complete the process.
1 . A method of creating a dental restoration for a patient's existing dental structure, comprising:
(a) obtaining a first 3D model of at least a portion of a first dental item;
(b) attaching the first dental item to the patient's existing dental structure;
(c) obtaining a second 3D model of the first dental item while attached to the patient's existing dental structure;
(d) aligning the first 3D model to the second 3D model;
(e) identifying a boundary curve on the first 3D model, and producing a third 3D model by using the boundary curve to trim the first 3D model;
(f) producing a fourth 3D model of a virtual dental item using the boundary curve, the third 3D model and the second 3D model;
(g) producing a second dental item from the fourth 3D model; and
(h) attaching the second dental item to the first dental item.
2 . The method of claim 1 where the first dental item is an implant abutment attached to an implant, where the portion comprises that portion of the abutment bounded by a margin curve.
3 . The method of claim 2 where the second dental item is a crown.
4 . The method of claim 1 where the production of the second dental item is obtained by a CAD/CAM milling machine.
5 . The method of claim 1 where the production of the second dental item is obtained through rapid prototyping.
6 . The method of claim 1 where the 3D digitized models are obtained using a scanning method without a scanning aid or an opaque agent used to facilitate scanning.
7 . The method of claim 1 where the first dental item is an implant, where the portion comprises that portion of the implant protruding above a bone.
8 . The method of claim 7 where the second dental item is an abutment.
9 . The method of claim 8 further including fitting a third dental item to the second dental item.
10 . The method as described in claim 9 wherein the third dental item is a crown.