Dr. Robert Pauley Jr.
DMD
• Graduate of the University of Kentucky College of Dentistry
• He holds memberships to:
American Dental Association
Georgia Dental Association
Computer Aided Implantology Academy
American Academy of Cosmetic Dentistry
• Board-certified Diplomate of the International Congress of Oral Implantologists
• Fellow of the ICOI Associate Fellow of the American Academy of Implant
Dentistry
introduction
introduction
The following five steps are the foundation of my everyday digital implant
workflow that I follow in order regardless of the type of procedure being performed:
- Take an intraoral scan. For the case presented below, I used a DEXIS IS 3800W scanner, a scanner/software combination I love. I have also used and still have the DEXIS IS 3600 and DEXIS IS 3700 models. The entire product line is solid and very reliable.
- Take a CBCT scan (if the case dictates).
- Merge the CBCT and intraoral scans into the DTX Studio Implant
software, which allows us to plan the specific implant for a particular site and case with a Prosthetic Driven Implant Planning (PDIP) approach. - Easily collaborate with laboratory technicians by exporting the intraoral scan files to the laboratory via DEXIS IS Connect for an immediate provisional design and fabrication.
- Use X-Guide software to dynamically navigate osteotomy drills and final implant placement.
the case
STEP 1: CBCT SCAN
A friend of mine experienced an issue with tooth #19 (Fig. 1) while on a ski trip in Telluride (CO, USA). The tooth was ultimately extracted by a local dentist who did a very nice job with the extraction and socket preservation.
Three months later, the patient had an appointment to evaluate the healed extraction site #19. A CBCT was obtained, and the treatment planning process was initiated.
One interesting aspect of this case was the availability of his intraoral scan from when his malocclusion was treated with aligner therapy a few years before. Its availability allowed us to plan his implant alignment and occlusion relative to his original crown contours. I imagine few of us keep the stone models, much less be able to locate them from prior orthodontic treatment. This case is an excellent example of the value of digital intraoral scans, which are easy to store and retain for possible later use. The initial preliminary treatment plan based on the CBCT scan led us to choose a 5.0 mm (D) × 11.5 mm implant (Fig. 2).
STEP 2: TAKE AN INTRAORAL SCAN
Again, the .stl files from a previous intraoral scan that included the patient’s
original tooth were available for this case. Therefore, using that previous scan during the treatment planning phase was convenient. Another notable fact regarding maximising a clinician’s chair time is the number of cases where the patient accepts treatment because the full-colour 3D component of an intraoral scan can be visualised.
To take this a step further, there is immense value in the patient being able to touch, handle, and see their printed current dentition compared to a diagnostic workup from the intraoral scan .stl files (Root Lab Cosmetic Blueprint) [1].
Our laboratory technicians can use the data sent through DEXIS IS Connect to fabricate a silicon matrix of the diagnostic workup and print a provisional single unit to full arch provisionals for cases to assist us in the clinical workflow. Again, having
the end result in mind before ever touching a patient’s tooth or preparing an osteotomy for an implant provides true prosthetically-driven treatment planning.
STEP 3: IMPLANT PLANNING IN DTX STUDIO IMPLANT
The next step is to import the CBCT and original intraoral scans into DTX Studio Implant and merge them to begin implant planning (Figure 3).
Note that the data on the patient’s #19 tooth can still be used in our plan even though it was extracted four months earlier.
I already know that once the implant is placed, everything that comes next will be at least 2.5 mm above the abutment implant interface to minimise marginal bone loss by maximising the ability to maintain biologic width. Current literature discusses
the influence of abutment height on peri-implant marginal bone loss [2]. DTX Studio Implant allows us to choose the implant and the abutments.
In this case, we could plan an On1™ (Nobel Biocare™) abutment with a 2.5 mm height to help us achieve this goal. The On1 abutment is placed at implant placement and never removed, allowing for a future workflow where healing heads, scan bodies, provisionals, and final placements take place 2.5 mm above the implant-abutment interface. Again, the literature supports that this workflow could lead to less implant-associated marginal bone loss.
Our ultimate goal is not to disturb any abutment/implant hard and soft tissue. Using Nobel Biocare implants with the Ti Ultra™ and the On1 Xeal™ pioneering Mucointegration ™ surfaces has also been shown to enhance this goal.
Here at the Dental Center of Atlanta, we use the On1 abutment protocol in most posterior cases and in maxillary anterior cases when alignment allows.
After the treatment plan is finalised in DTX Studio Implant, it is exported onto a flash drive as a .xgx surgery, ready for import into X-Guide for dynamic navigation.
STEP 4: DYNAMIC NAVIGATION IN X-GUIDE®
The surgical files are now imported into X-Guide to finalise this case. Fig. 4 shows that the planned 5.0 mm (D) × 11.5 mm implant comes out of the central fossa of the tooth correctly in the mesial/distal and buccal/lingual directions.
The next step is to use X-Guide and X-Mark™ to calibrate for navigated surgery. This step occurs on the day of surgery when X-Mark technology is used to virtually register the patient tracker (in this case, an X-Clip adapted to the patient’s contralateral side) with the handpiece tracker. Three spots are selected on the patient’s 3D rendering corresponding to the same three spots in the patient’s mouth (in this case, they were located on the patient’s natural dentition).
An acceptable spread quality was obtained in this case, and the three locations were all under 0.5 mm deviation, which is ideal. If we have a location that is not this precise, we can use the X-Guide software refinement application, which allows the clinician to pick 3–4 teeth and ‘paint’ their buccal, lingual, and incisal/occlusal surfaces using the Probe Tool to finalise calibration.
Fig. 5 shows the X-Point Target, which appears like a bullseye, and the goal is to keep everything centred. The clinician looks at this target to dynamically guide the osteotomy drills and the final implant placement.
First, they focus on the dot in the middle of the target, which is where the point of the osteotomy drill will need to penetrate the cortical plate. The second green circle is the implant radius, and the third is the depth guidance. The depth guidance will be displayed in yellow until the drill is 0.5 mm from the planned depth, at which point it will turn green as a visible indicator. There will also be an audible notification when the planned depth is achieved. If you go beyond the planned depth, the circle will turn red as another visible indicator.
At a depth of 10.6 mm, there was only a 0.5° angle of deviation, which is ideal relative to the osteotomy plan mesiodistally and cross-sectionally. Planning allows us to maintain a safe distance from vital structures, the inferior alveolar vascular bundle in this case. This small deviation gave me confidence that the implant was being placed where I planned it. Literature also confirms this by documenting that implant placement using dynamic navigation is more accurate than free-hand placements [3].
LAB FABRICATION
The Nobel Parallel™ CC is next dipped in PRF.
The On1 abutment still has its Xeal surface attached to its carrier; care is taken not to touch or expose the surface of the On1 abutment to any of the patient’s saliva. Again, we have selected an abutment that keeps the abutment crown interfaces at least 2.5 mm above where the implant is placed, providing the correct biological width to our soft tissue and reducing the chance of bone dieback.
Fig. 7 shows the placed Xeal. It is right at or slightly below the soft tissue level. We had adequate Osstell readings of 68 buccal/lingual and 65 mesial/distal, so we felt comfortable placing an implant at this site. This case is one of those where you need to gauge your patient’s ability to follow your postoperative instructions. I knew this patient well and knew that he would follow my directions regarding dietary and other needs.
Fig. 8 shows the laboratory-fabricated shell. They use Exocad software and will design the temporary shell from the surgical files I sent. The wings are on adjacent teeth to help with the seating of the shell over the abutment plan.
Fig. 9 shows the screw-retained temporary coping for an On1. It is seated (we will need to relieve the height), and the laboratory designed and fabricated a temporary shell. After the temporary coping’s height is reduced extraorally, it is re-seated and heightened into place and silicone tape is placed over the screw access hole (Fig. 10).
Next, the provisional shell is tried in; in this case, the laboratory did a great job, which is the beauty of a digital workflow in that the restorations are incredibly accurate and need minimal adjustment, with only a little relieving needed on the distal side to ensure there was sufficient room for the pickup material (Fig. 11).
Fig. 12 shows the pickup of the provisional shell made using flowable temporary material. Next, the provisional was untightened and retrieved, the wings were removed, and the screw-retained provisional crown was adjusted to ensure no occlusal contact. In this case, the On1 provisional shell provided an adequate root emergence profile with minimal need to polish or contour after the venus pickup.
Fig. 13 shows the final temporary shell. Silicon tape is again inserted into the access, global composite to cover, and we are done.
“Literature tells us that the utilization of an IOS helps eliminate potential errors during acquisition.”
conclusion
conclusion
REVIEWING MY WORK
When you first begin using the X-Guide navigation system, you might wonder how accurate you are. You can send the laboratory a postoperative CBCT, and they can transpose your actual implant crown over where your implant was placed (Fig. 14).
You can see that this placement was extremely accurate. While it is slightly off from the dense cortical lingual plate, I am pleased with the accuracy of the placement compared to my plan. As mentioned earlier, minimal adjustment was needed for the
temporary placement. You can see it nicely out of occlusion five days postoperative (Fig. 15).
The patient had a temporary placement holding in the bone graft material, and there was nice, healthy-looking osseointegration.
The patient was very happy to have a temporary placement, and I was pleased to see a minimal wound postoperative because we did not have to reflect a flap by using a dynamic navigated surgical workflow.
When we are ready to take the final impression, the intraoral scanner will be used again. After the scan is checked for data and bite accuracy, you proceed to the Scan Body Capture and final check. The finalised .stl files are then sent via IS Connect to your preferred laboratory with the patient’s prescription and associated photo or radiographic images.
The literature tells us that using an intraoral scanner helps to eliminate potential errors during acquisition and real-time viewing, eliminates the need for impression and bite registration materials and stock trays, and decreases a dentist’s chairside work time [4].
HOW TO DECREASE PERI-IMPLANT TISSUE DISTURBANCES
- Flapless/minimal flap surgery
- Minimal (or no) abutment changes
- One-time abutments
- Screw-retained prosthetics (whenever possible); and
- Cement-retained restorations.
Collaborate with the laboratory and tell them you want this abutment to be at least 2.5 mm with a concave surface and the crown margins to be 1.0–1.5 mm subgingival on the buccal and 0.5 mm to the right at the gum level on the sublingual. All of this will
help with removing the cement.
THE MOST IMPORTANT THING YOU CAN DO
This type of treatment begins by taking an intraoral scan with your DEXIS IS scanner with IS ScanFlow software, then planning your treatment using DTX Studios Implant software, and finally using X-Guide to perform your dynamic placements.
“Every patient, every implant, every time.”
SOURCES
1. Jafri Zahmad N Sawai M Sultan N Vhardwha A. Digital Smile Design – An innovative tool in aesthetic dentistry J Oral Biol Craniofac Res. 2020 April – June: 10 (2: 194-198)
2. Chenz L Cylij, Wang H L Yu H: Influence abutment height perioimplant marginal bone loss a systemic review in meta analysis. J Brostet Bent. 2019: 122 (1: 14-21) ease an Edward 2
3. Block MS, Emery RW, Lank K, Ryan J. Implant Placement Accuracy Using Dynamic Navigation. Int J Oral Maxillofac Implants. 2017;32(1):92-99. doi:10.11607/jomi.5004)
4. Lee CY, Wong N, Ganz SD, Mursic J, Suzuki JB. Useof an Intraoral Laser Scanner During the Prosthetic Phase of Implant Dentistry: A Pilot Study. J Oral Implantol. 2015;41(4):e126-e132. doi:10.1563/AAIDJOI-D-13-00132