2022 ACP Annual Session

Computer-aided design and manufacture of implant indexing device for accurate repositioning of non-engaging abutment

Christian Loo, DMD

The Ohio State University

Patient Presentation

-64-year-old female presents with a dislodged three-unit implant fixed prosthesis.

-Failure due to screw loosening and screw fracture.

-Prosthesis was screw retained to implants #3, #4 and to angled, non-indexed abutment #5 (Astra Tech, OsseoSpeed Tx, Dentsply).

-Accurate repositioning of the dislodged abutment would not be possible because it is non-engaging.

Aim

-To describe an implant indexing device to accurately position a non-engaging abutment.

-To describe the computer-aided design and manufacture process of this indexing device.

Methods

-Implant analogs were connected to abutments. (1)

-Non-engaging abutment was connected. (2)

-Definitive cast was poured. (3)

-Prosthesis was removed, leaving abutment. (4)

-Healing abutments (Ø 4.5 4 mm, Astra Tech OsseoSpeed Tx, Dentsply) were placed on implant analogs of #3 and #4. (5)

-Definitive cast with oriented abutments was scanned using benchtop scanner (E3, 3Shape A/S).

-Index with abutment screw access hole was designed using surgical guide module of implant planning software (Blue Sky Plan, Blue Sky Bio). (6)

-Index was printed (NextDent 5100, NextDent SG, 3D Systems, Inc.). (7)

-After second-stage surgery, healing abutments were placed at site 3 and 4 (8)

-Abutment was placed and oriented using index.

-Abutment screw was placed through access hole and torqued to 25 N/cm. (9)

-Healing abutments were removed, and prosthesis was placed. Passivity was verified. (10)

-Pero-apical radiograph was taken to confirm complete seating of all abutments. (11)

Results

Implant indexing device can orient a non-engaging stock abutment and maintain abutment position during torquing of abutment screw.

Conclusion

Difficulties in abutment positioning can be predictably overcome with digitally designed indexes.

Computer-aided design and manufacture of implant indexing device for accurate repositioning of non-engaging abutment.