Restorative challenge: A 47-year-old female lost tooth #9 due to trauma from a car accident and had a Nobel Biocare 4.3 Replace™ Select implant placed. She had thin gingival tissue, and esthetics was a concern in the anterior zone. The patient and dental team wanted the best esthetic result possible.
Treatment Plan: Using the Procera system, the team planned to design a custom zirconia abutment that would be processed and milled by Nobel Biocare. The abutment would then be scanned for a Procera alumina coping that would be layered with porcelain for the best esthetic results.
These Procera custom abutments are similarly priced to stock abutments and Procera offers a three-day turnaround from waxup to finished product. An advantage of using the Procera system is that it would allow the technician to create a custom alumina ceramic coping to fit the manufactured zirconia abutment.
Restorative Team: Brian Brock, CDT, implant specialist for Gaines Dental Lab, and restorative dentist William Fain, DMD, both in Lexington, Kentucky. Nobel Biocare processed and milled the custom zirconia abutment and milled the alumina coping.
Case study: After the implant was placed, Brock made a temporary restoration to help preserve the soft tissue contours (see Figure 1). He also provided Dr. Fain with a customized impression post that allowed contouring of the soft tissue for the laboratory's working model.
Once the laboratory received the dentist's impression, Brock poured the soft tissue model, modified the plastic temporary abutment and waxed it to ideal contour (see Figure 2). He then took the waxup, placed it into the abutment platform holder and blocked out the screw access hole.
He placed the waxed abutment into the Forte scanner, launched the Procera software and scanned the abutment (see Figure 3). When finished, he had a three-dimensional image of the waxed abutment. Using the Procera software, he then placed the virtual abutment inside a visual cylinder "zone" and established the angle, height and width of the abutment. The cylinder acts as a reference for the technician so he can verify that the abutment can be manufactured from the parameters he has set and avoid any processing delays (see Figure 4).
Brock then chose the appropriate implant platform for the case in the Procera software. He then sent the file via the Internet to the Procera Milling Center in Mahwah, New Jersey, where the zirconia abutment was milled and returned to him two days later. The zirconia abutments were returned with a screw access hole cylinder (also known as a "chimney"), which the lab modified with a contour stone and copious amounts of water.
Since the patient and dentist had selected an all-ceramic restoration, the laboratory scanned the abutment, designed the alumina coping, sent the data to Nobel Biocare for milling and received the coping two days later. The laboratory applied NobelRondo™ porcelain and the finished case was sent to the dentist.
Dr. Fain placed the custom abutment, and verified that it was completely seated with a radiograph. Using a torque wrench, he tightened the screw to 35Ncm. He then placed the Procera Alumina crown to complete the case. Both the dentist and the patient approved the shade and contacts before final cementation. The patient was very satisfied with the final results and has referred many of her family and friends to Dr. Fain for restorative treatment (see Figure 5).
Contact information: Nobel Biocare USA: 800-993-8100, 714-282-4800, or http://www.nobelbiocare.com">click here to visit the company's website.