Dr. Riley Clark discusses how virtual surgical planning (VSP) and cone beam computed tomography (CBCT) add to clinical accuracy and efficiency
Our teaching institute emphasizes practical education. A hallmark example of this is our “one-on-one” mentoring program. This collaborative approach is powerful, as doctor colleagues work together with one goal in mind — achieve the best treatment outcome for our patients. Embracing digital planning in our mentoring program has proven a powerful aid to our doctors’ ability to deliver better care for their patients. Digital technology opens doors to procedures that were never thought possible. In this case, an out-of-state doctor did more than just refer her patient to our institute for treatment, but traveled with him to gain hands-on experience with our technology and perform the surgery alongside my father and me. She walked away from the case impressed with how virtual surgical planning (VSP) and cone beam computed tomography (CBCT) augment surgical and prosthetic outcomes. Most importantly, the patient walked away with an amazing result.
The male patient presented at the referring doctor’s office in need of a full-mouth rehab. Treatment options included crown-and-bridge work to salvage the remaining teeth with conventional restorative methodology, extraction, and dentures, or a fixed implant solution. The patient opted for implants. Our mentoring program often lowers the barrier to entry that all our patients struggle with — price. For a fraction of the “retail” price, our mentoring doctors are able to offer premium implant services at a more manageable fee. To start designing the case, a PVS impression, bite registration, and a CBCT scan were taken by the referring doctor.
The traditional impression was digitized by our lab, WhiteCap Dental Lab and Milling, and the STL file and DICOM from the CBCT were then merged in Dental Planning Software (DPS) (360imaging®) (Figures 3 and 4). Multiple implants were planned (Figure 1) with two thoughts in mind — first, maximize the primary stability of each implant, and second, ensure the implants were in a an ideal restorative position (Figure 2). To achieve this outcome, a digital wax-up was used (from exocad) in the planning phase. The digital wax-up was also used to finalize both full-arch temporaries — in this case, milled polymethylmethacrylate (PMMA) (Figures 5 and 10).
Figure 1 and Figure 2
Figure 3 and Figure 4
With both implants and temporaries planned, next we chose what guide type/design will act as the vehicle to deliver this product to the patient. A variety of options are available for such a case. Because of our partnership with 360imaging, we were thrilled to use a new type of guide that, at the time, had a patent pending. This ingenious design features a buccal bone support, called the anatomical guide, to which all components of the case would seat to utilizing their patented diamond latch system. This leads to incredibly accurate relationships of the planned implants relative to bone and to the pre-made lab temporaries. Another highlight is the anatomical guide is seated from a vertical stop referenced to the natural teeth (Figures 6 and 11). This case, along with its thoughtful guide design, epitomizes clinical accuracy and efficiency in full-mouth implant rehab (Figures 7-9).
Figure 5 and Figure 6
Figure 7 and Figure 8
Figure 9 and Figure 10
To summarize some benefits of the diamond latch guide:
- Up to 75% smaller than comparable guides
- Requires no lingual or distal tissue reflection
- One point of reference for all attachments (including vertical seating piece, implant guide, PMMA)
- Increased accuracy compared to other guide systems
- Stronger compared to other guide systems
On the day of surgery, the patient was moderately sedated via IV access and locally anesthetized with Septocaine®. We started on the maxillary arch. The guide protocol dictated that a few teeth be removed first to ensure a passive fit of the anatomical guide and the vertical stop over the remaining maxillary teeth. After those few teeth were removed, a buccal flap was reflected, and the anatomical guide was seated to the buccal plate with the help of the vertical stop resting on the occlusal surface of the maxillary teeth (Figure 11).
After the anatomical guide was fixated to the buccal plate and the vertical stop removed (Figure 12), all remaining teeth were extracted (Figure 13), leaving No. 2. Tooth No. 2 and No. 31 were deemed helpful with this case by acting as an occlusal stop and providing proprioceptive feedback to the patient during the healing phase of the implants. One novel benefit of this guide design is the additional support the buccal plate has. Often during extractions, a thin (and sometimes not so thin) buccal plate can be fractured and may mandate a change in implant position. The anatomical guide supported the buccal plate and protected the bone from excessive trauma during the extractions. After extractions, bone reduction was done using the anatomical guide as a reference. With the teeth removed and the bone reduced, it was time to thoroughly debride the extraction sites with a curette and rotary side-cutting bur.
Figures 12, 13, and 14
Figures 15, 16, and 17
Next, the implant guide was secured to the anatomical guide with two horizontal pins in the posterior and one vertical stop at the anterior (this is referred to as the diamond latch system). The implants were placed following the drilling protocol to maximize primary stability (Figure 14). Then the implant guide was removed from the anatomical guide, and non-hexed, temporary metal cylinders were placed in all implants. The cylinders had been prepped during the lab stage to ideally fit the PMMA temporaries. Since they were non-indexed, timing of the cylinders were visually determined based on their relative position on the lab printed analog model (Figure 15). Seating jigs were not used for this process because minor changes in implant position often exist and deem the seating jigs useless. After the cylinders were placed, bone grafting was performed in extraction sites around implants. Then dermal tissue was taken, with holes punched so it could fit over the temporary cylinders to cover the alveolar ridge. The use of dermal tissue leads to a thicker connective tissue layer after healing.
At this point, the surgical phase of the treatment was put on hold, and the temporary PMMA was seated (Figure 16). Again, the genius of this guide system is designing the diamond latch system into the PMMA (Figure 9). In this design, the anatomical guide served as a constant landmark to which all other components were referenced. Minor adjustments were made to ensure ideal spacing for “pick up” material around the temporary abutments. A tissue spacer was placed between the PMMA and the dermal tissue. The “pick up” was done with a dual-cure resin with the PMMA securely attached to the anatomical guide. The PMMA diamond latches were cut off, allowing the anatomical guide to be unscrewed from the buccal plate. The PMMA remained fixed to the implants, however; and suturing was done around PMMA. This PMMA “pick up” process took about 30 minutes (Figure 17).
The same procedure was repeated on the lower arch. Our “pick up” procedure followed a more traditional approach of removing the PMMA and making adjustments extraorally, while suturing procedures were completed. Ultimately, the lower “pick up” approach was advantageous because of the time efficiency and ability to contour the intaglio of the PMMA more exactly. Occlusal adjusted and refinements were made to the fit and feel of the PMMAs (Figure 18).
Postoperative CBCT scans were taken with a CS 8100 3D (Carestream Dental) to provide a baseline and track healing (Figures 19 and 20). The patient will begin final restorative procedures in 5-7 months.
Figure 19 and Figure 20
Figure 21: Two weeks post-op
What made this case predictable and even possible? The answer is the synergy of a thoughtful clinical team and powerful technology. Technology helps us execute surgical and prosthetic rehabilitation with accuracy and efficacy. Technology allows us to convert complex cases into manageable and practical cases. In fact, I would say the least stressful part of the entire case was placing the actual implants, which was historically the most stressful part of these cases when I was freehanding implant placement. From the technology, to the labs and their technicians, to the mentoring doctor, to the assistants, to the patient, this was a collaborative effort, and I would call the case a collaborative win.
- Dr. Evon Heaser, Mentoring Doctor
- 360imaging®, Mark Palmer, CEO
- Dr. P.K. Clark, WhiteCap Institute Clinical Director
- WhiteCap Dental Lab and Milling, Jim Campbell, Guide Department Manager
- Whitecap Dental Lab and Milling, David Nowaskey, CAD Department Manager
Disclosure: Dr. Clark is a key opinion leader for Carestream Dental.