Laboratory attachment jig for prosthodontic restoration

A laboratory attachment jig is described for use in accurately positioning an attachment relative to an implant abutment/fixture analog of a working model. This jig comprises an orientation arm having a first end and a second end, the orientation arm including a fastener for securing the orientation arm to the abutment/fixture analog of the working model. A primary support member is attached to the second end of the orientation arm, with the primary support member and the orientation arm being supported transversely in a first plane. The primary support member includes a vertical positioning sleeve and a fastener for the vertical positioning sleeve. A lateral support arm is attached to the vertical positioning sleeve of the primary support member and includes an end. A mandrel support member is attached to the end of the lateral support member for retaining the attachment. The lateral support arm includes a lateral positioning sleeve and a fastener for the lateral positioning sleeve. In use, the lateral support arm is adapted to be movable up or down on the primary support member upon loosening of the fastener for the vertical positioning sleeve and is adapted to be movable forward or backward relative to the primary support member upon loosening of the fastener for the lateral positioning sleeve.

TECHNICAL FIELD 
The present invention relates generally to implant restorative dentistry 
and more particularly to a laboratory attachment jig for use during 
prosthodontic restoration to accurately position an attachment to an 
implant abutment/fixture analog located on a working model. 
BACKGROUND OF THE INVENTION 
When implants are used with natural teeth, attachments are usually 
indicated as stress breakers. At other times, it may also be advantageous 
to incorporate attachments into frameworks when restoring implants. 
Traditionally, a surveyor or similar tool is used to parallel and place 
attachments in a working model. Unfortunately, however, many technicians 
are uncomfortable with using a surveyor and thus cannot or do not achieve 
the optimal benefits thereof. Further, use of a surveyor requires 
significant precision and the process is often time-consuming and costly. 
There is therefore a need for improved methods and devices for use in 
extra-oral placement and positioning of attachments in a dental 
restoration. 
BRIEF SUMMARY OF THE INVENTION 
It is an object of the present invention to provide a novel laboratory 
attachment jig for use during dental prosthodontic restoration. 
It is a further object of the invention to use the laboratory attachment 
jig for paralleling an attachment to an implant abutment/fixture analog 
located on a working model. 
It is still another object to provide a laboratory attachment jig that is 
simple to use and that reliably and accurately positions an attachment in 
a working model for use in a dental restoration. 
It is yet another object to provide a method for using a laboratory 
attachment jig during a prosthodontic restoration that provides enhanced 
precision and reduced working time for the technician as compared to prior 
art surveyor techniques. 
These and other objects of the invention are provided in a laboratory 
attachment jig for use in accurately positioning an attachment relative to 
an implant abutment/fixture analog of a working model. This jig comprises 
an orientation arm having a first end and a second end, the orientation 
arm including a fastener for securing the orientation arm to the 
abutment/fixture analog of the working model. A primary support member is 
attached to the second end of the orientation arm, with the primary 
support member and the orientation arm being supported transversely in a 
first plane. The primary support member includes a vertical positioning 
sleeve and a fastener for the vertical positioning sleeve. A lateral 
support arm is attached to the vertical positioning sleeve of the primary 
support member and includes an end. A mandrel support member is attached 
to the end of the lateral support member for retaining the attachment. The 
lateral support arm includes a lateral positioning sleeve and a fastener 
for the lateral positioning sleeve. In use, the lateral support arm is 
adapted to be movable up or down on the primary support member upon 
loosening of the fastener for the vertical positioning sleeve and is 
adapted to be movable forward or backward relative to the primary support 
member upon loosening of the fastener for the lateral positioning sleeve. 
The foregoing has outlined some of the more pertinent objects of the 
present invention. These objects should be construed to be merely 
illustrative of some of the more prominent features and applications of 
the invention. Many other beneficial results can be attained by applying 
the disclosed invention in a different manner or modifying the invention 
as will be described. Accordingly, other objects and a fuller 
understanding of the invention may be had by referring to the following 
Detailed Description of the preferred embodiment.

DETAILED DESCRIPTION 
Referring now to FIG. 1, the laboratory attachment jig 10 of the present 
invention comprises an orientation arm 12, a primary support member 14, a 
lateral support arm 16, and a mandrel support member 18. Each of these 
structural members are preferably formed of a rigid plastic or lightweight 
metal material. The orientation arm has a first end 20 and a second end 
22. The primary support member 14 and includes a first end 21 and a second 
end 23. Primary support member 14 is mounted at its first end 21 
tranversely to the second end 22 of the orientation arm 12 substantially 
as shown. Orientation arm 12 and primary support member 14 are thus 
located in the same plane. A threaded opening 24 adjacent the second end 
22 of the orientation arm 12 receives an analog fastening screw 26. The 
end 28 of the analog fastening screw is adapted to be secured to an 
implant abutment fixture analog located on a working model as will be 
described below. A ball pivot joint 19 may be provided to enable the 
member 14 to pivot relative to the orientation arm 12 when the arm is in a 
fixed position. If the pivot joint 19 is used, a lock (not shown) is also 
provided to fix the position of the member 14. 
The primary support member 14 is generally square-shaped in cross-section 
and includes a vertical positioning sleeve 30 and set screw 31. The 
lateral support arm 16 is attached to the vertical positioning sleeve 30 
and thus is movable therewith. By loosening the set screw 31 (or other 
suitable fastener), the lateral support arm 16 is movable up and down on 
the primary support member 14 relative to the orientation arm 12. By 
tightening the set screw 31, the vertical position of the lateral support 
arm 16 is then fixed. 
As seen in FIG. 1, the lateral support arm 16 is located in (and moves 
vertically in) a plane slightly offset from the vertical plane in which 
the primary support member is located. Lateral support arm includes a 
first end 32 and a second end 34, and a lateral positioning sleeve 36. A 
set screw 37 is supported in the positioning sleeve 36 and is loosened to 
enable the lateral support arm 16 to move laterally (i.e., forward and 
backward) relative to the primary support arm 14. 
The laboratory attachment jig 10 also includes the mandrel support member 
18 that is attached to the second end 34 of the lateral support arm 16 via 
a pivot joint 38. The mandrel support member 18 includes an internal bore 
in which is received an attachment mandrel 42. The attachment mandrel 42 
includes the attachment 44 to be positioned. A mandrel set screw 45 is 
used to retain the attachment mandrel (with the attachment) in the mandrel 
support member. The pivot joint 38 enables the mandrel support member 18 
to pivot approximately 15 degrees relative to the axis passing through the 
lateral support arm 16. A suitable lock (not shown) fixes the position of 
the pivotable member 18. 
The use of the laboratory attachment jig 10 shown in FIG. 1 can now be 
described with reference to the method diagrammed in FIGS. 2-7. As seen in 
FIG. 2, the laboratory attachment jig is particularly adapted for use 
extra-orally in connection with a working cast model 50. The working model 
is a simulation of the patient's lower jaw (by way of example only) and 
includes a plurality of teeth 52 (representing the patient's natural 
teeth), at least one implant abutment 54, and an implant abutment/fixture 
analog 56. According to the method, it is desired to properly position the 
attachment 44 adjacent the implant abutment 54 (which represents the 
position of an osseointegrated dental implant in the patient's mouth) 
parallel to the implant abutment/fixture analog 56. 
Referring now specifically to FIG. 2, the method begins by securing the 
attachment mandrel 42 (with the attachment 44) to the mandrel support 
member 18 and generally positioning the jig over the cast model. The 
method continues in FIG. 3 with the technician securing the analog 
fastening screw 26 to the implant abutment/fixture analog 56. Referring 
now to FIG. 4, the attachment 44 is then positioned relative to the 
implant abutment 54 in the correct mesio-distal and occluso-cervical 
orientation by manipulating the lateral support arm 16 up or down relative 
to the primary support member. As noted above, this is accomplished by 
loosening the set screw 31. The attachment is placed in the correct 
bucco-lingual position by manipulating the lateral support arm forward or 
backward upon loosening the set screw 37. Once the positioning is 
complete, the set screws are tightened. 
Referring now to FIG. 5, the method continues by waxing (with wax 57) the 
attachment 44 to the adjacent abutment 54. As seen in FIG. 6, the mandrel 
42 is then separated from the attachment 44. At FIG. 7, the jig 10 is 
removed from the working model. The attachment 44 is now secured to the 
abutment 54, paralleled to the implant analog 56, and ready to be 
completed with standard prior art procedures. The completed working model 
is shown in FIG. 8. 
As noted above, the jig 10 advantageously includes a 15.degree. pivot joint 
between the second end of the lateral support arm and the mandrel support 
member. This enables the jig to be used as a surveying tool and to thus 
allow for fabrication without the attachment 44. For example, abutment 54 
could support a coping, and a fixed bridge could then be drawn between the 
abutment and the analog 56. 
In particular, the orientation arm 12 is first attached to the analog 56 as 
in FIG. 3. The mandrel support member 18 (and/or mandrel 42) is then 
oriented over the coping. Angular variations in the orientation of the 
coping are then taken into consideration by pivoting and adjusting members 
14 and 18 (via ball joints 19 and 38). The coping is then waxed. 
It should be appreciated by those skilled in the art that the specific 
embodiments disclosed above may be readily utilized as a basis for 
modifying or designing other structures for carrying out the same purposes 
of the present invention. It should also be realized by those skilled in 
the art that such equivalent constructions do not depart from the spirit 
and scope of the invention as set forth in the appended claims.