From Intraoral Scan to Final Custom Implant Restoration
This case demonstrates the optical scanning of Glidewell Laboratories' purpose-made Inclusive® Scanning Abutments utilizing the iTero™ digital scanning system (Align Technology; San Jose, Calif.) with software version 4.0. Digital data was used in conjunction with laboratory CAD/CAM planning to fabricate custom all-ceramic implant abutments and a final 4-unit fixed prosthesis. The abutments and fixed prosthesis were fabricated using advanced computer-aided milling technology.
The patient in this case was a 52-year-old healthy Hispanic male who sustained a traumatic avulsion and loss of his maxillary incisors in an automobile accident. Following healing, the patient reported that a 4-tooth transitional removable partial denture was constructed. He was seen by the oral and maxillofacial surgery service of Virginia Commonwealth University, as he desired dental implant therapy. The patient reported multiple incidents of a "broken" provisional denture (Fig. 1).
The patient was informed of the alternatives, benefits and potential complications of various treatment options before confirming his desire to pursue implant restoration of his missing anterior teeth. The treatment plan included placement of two Replace® Select Straight RP 4.3 x 13 mm implants (Nobel Biocare; Yorba Linda, Calif.) with 5 mm healing abutments, followed by a six-month healing period and restoration with all-zirconia custom abutments and a 4-unit all-ceramic fixed prosthesis to restore the anterior incisors to form and function.
Using local anesthesia, two Replace Select Straight RP implant fixtures were placed in the area of tooth #7 and #10 using standard Nobel Biocare implant placement protocol. Placement angulation and depth were verified and appeared to be satisfactory (Fig. 2). Standard RP 5 mm healing abutments were placed, and the fully reflected tissue flap was closed with interrupted sutures (Fig. 3).
Following six months of healing post implant placement, intraoral photos were taken to record and confirm the healthy remaining dentition (Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8). Osseous integration was confirmed with a panoramic X-ray (Fig. 9), followed by resonance frequency analysis (RFA) using an Osstell® ISQ implant stability meter with SmartPeg™ attachment (Osstell Inc. USA; Linthicum, Md.) (Fig. 10), which displayed an implant stability quotient (ISQ) of 78 on a minimum-to-maximum scale of 1-100. Counter rotation with a torque wrench confirmed no rotation to 35 Ncm. Based on this evidence of stability, the implant fixtures were deemed to be acceptable for restoration.
The 5 mm healing abutments were removed (Fig. 11) and purpose-made Inclusive Scanning Abutments (Fig. 12) were placed and hand-tightened over the implants with the accompanying titanium screws (Fig. 13, Fig. 14).
Using the iTero scanner with updated software (version 4.0), a full maxillary arch scan, full mandibular arch scan and centric bite in maximum intercuspation were completed. A three-dimensional digital record of the patient's anatomy was created from these scans (Fig. 15) and electronically submitted to Glidewell Laboratories to be used in the CAD/CAM restoration process.
At Glidewell Laboratories, the virtual scan was registered to
the scanning abutments (Fig. 16, Fig. 17). This provides the dental technicians with the implant system, size, axis, position relative to the adjacent anatomy and locking feature orientation. A virtual zirconia abutment was designed using 3Shape's DentalDesigner™ software (3Shape Inc.; New Providence, N.J.) and the Glidewell Digital Abutment Library (Fig. 18, Fig. 19, Fig. 20, Fig. 21).
From this, the corresponding physical Inclusive All-Zirconia Custom Abutments (Glidewell Laboratories) were milled. Similarly, a BruxZir® Solid Zirconia 4-unit fixed bridge (Glidewell Laboratories) was designed and milled using this state-of-the-art CAD/CAM technology.
The custom zirconia abutments were trial-fitted in the patient's mouth with some slight tissue blanching noted (Fig. 22). The individual close-up views demonstrate how close the labial path of insertion passed to the head of each abutment's titanium screw (Fig. 23, Fig. 24).
In the same visit, the completed 4-unit all-ceramic milled BruxZir Solid Zirconia bridge was trial-fitted and examined for proper occlusion (Fig. 25, Fig. 26). There was "tight" anterior coupling for this case as evidenced by the history of provisional denture fracture. The occlusion was checked and presented as so precise that no adjustment was required. The anterior view of the final prosthesis demonstrates optimal mesial-distal width proportion, incisal edge proportion, pontic-tissue contact and excellent shade/esthetics (Fig. 27). Further, the occlusal view demonstrates an optimal incisal edge arch form (Fig 28). The soft tissue lip position and speech phonetics appeared to be optimal (Fig. 29). Following the trial fitting, the fixed bridge was removed, the zirconia abutment retention screws torqued to 35 Ncm, the abutment screws covered with cotton/Cavit™ Temporary Filling Material (3M™ ESPE™; St. Paul, Minn.), and the prosthesis cemented with GC Fuji PLUS™ (GC America; Alsip, Ill.).
The final full-face photo demonstrates the pleasing smile achieved with the restorative result (Fig. 30).