Faith M. Simiyu
| Faith M. Simiyu |
Faith M. Simiyu, Julian Conejo, Leslie Stone Hirsh, Jay Dubin, Karina Hariton-Gross
Karina Hariton-Gross
Prosthodontics, University of Pennsylvania, School of Dental Medicine
Introduction
Objective: To fabricate dental implant prostheses, an impression must be taken of the implant by inserting an impression coping into the implant and picking it up in an impression. Adjacent implants placed with converging angulations create a unique challenge in inserting both impression copings and capturing their precise position simultaneously. When impression copings converge, traditional techniques using open and closed tray impression copings may not be possible, and other techniques and creative solutions must be established. An accurate impression is essential for precise capture of an implant’s spatial position to accurately design, fabricate, and insert the implant prosthesis. The purpose of this study is to examine a case in which two adjacent implants with converging angulations were accurately impressed with digital technology using scan bodies for fabrication of the implant prosthesis with CAD/CAM technology.
Methods
Materials: Nobel Biocare implants Ø 5x10mm, Nobel Elos Accurate® Scan Body 5mm, Sirona CEREC Primescan AC, FG #379 diamond bur, FG #368 diamond bur, Accufilm articulating paper Methods: Dental implants at sites #30 & #31 were placed at converging angulations. To capture their precise spatial relationship and angulation and produce an accurate digital impression, scan body at implant site #31 was placed first. Articulating paper was placed between #30 and 31, and the second scan body #30 was tried in. The articulating paper marked the proximal point of contact which prevented complete seating of the second scan post. The marked area was relieved with an ovate shaped diamond bur, without altering the occlusal surface of the second scan post. Insertion of scan post #30 was tried again, and the process of reduction and modification was repeated until both scan bodies were able to seat fully and simultaneously with no proximal contact. Following a vertical bitewing to confirm complete seating, a digital impression was taken using the Cerec Primescan to simultaneously and accurately capture both implants. Results: While initially the utilization of scan bodies for a digital impression produced the same challenges of impingement as traditional open and closed tray impression copings due to the converging angulation, following modification of the second scan post both scan posts were able to fully seat without contact, and an intraoral scan captured both the precise angulation and spatial relationship. The laboratory was then able to design and mill a monolithic zirconia restoration with custom titanium abutments.
Results
Results: While initially the utilization of scan bodies for a digital impression produced the same challenges of impingement as traditional open and closed tray impression copings due to the converging angulation, following modification of the second scan post both scan posts were able to fully seat without contact, and an intraoral scan captured both the precise angulation and spatial relationship. The laboratory was then able to design and mill a monolithic zirconia restoration with custom titanium abutments.
Conclusion
n/A