Working as a team

Drs. Iham Gammas and Haroutioun Kotchinian collaborate for more predicable surgical and restorative results

This 77-year-old retired male sought dental treatment due to difficulty chewing and poor esthetics caused by missing teeth. His medical history revealed high blood pressure, an allergy to penicillin, and current medication with Losartan. His dental history indicated a lack of oral hygiene resulting in tooth decay and significant tooth loss. Previous dental treatments included fillings, extractions, and dentures, but the ill-fitting dentures caused discomfort while eating, speaking, and smiling.

During the clinical examination, the patient displayed multiple missing, decayed, and broken teeth, along with severe wear on his remaining teeth. His high lip line and relatively good positioning of the remaining anterior teeth relative to his lips were noted.

A comprehensive treatment plan was developed, which consisted of the following steps:

• Extraction of teeth Nos. 3 and 11.
• Placement of eight Ditron dental implants in the lower arch to support a full-arch fixed dental prosthesis.
• Placement of three Ditron implants in the upper arch for single implant restorations.
• Preparation of the upper arch by Dr. Kotchinian and final impression incorporating the three dental implants.
• Upper arch fabrication using exocad software to merge preoperative full smile photos with the final impression, customizing the smile line based on the patient’s extraoral features.
• Ideal restoration of the upper arch 2 months after surgery.

Surgical procedure — Dr. Iham Gammas

This is a case of teamwork, as I performed the surgical aspect, and Dr. Kotchinian completed the restoration. We frequently do these types of full arch rehabilitations in tandem. The patient presented with a complete denture for the lower arch and upper arch where most of the teeth were salvageable except for teeth Nos. 3 and 11. The plan was to restore to 1st molar occlusion.  Using the CBCT as a diagnostic, we were able to plan the case with more prosthetic predictability since it acted as another part of the final blueprint for the case.

I plan all cases using a CBCT scan-based planning software.  For my surgeries, I like to do full thickness incisions and flaps to fully expose the buccal and lingual surfaces of bone. This way I get a good feel for the surgical site, unrestricted views, and ultimately, a more fine-tuned placement of implants. This is especially important in thinner ridges. I am also in a better position to manipulate the soft tissue and am more prepared for a potential need for bone grafting. If a planned implant is in proximity to the mental foramina, I like to expose up to the foramina and keep a note of it. A nice piece of armamentarium that will make full-arch surgeries easier is the use of OptraGate by Ivoclar. This latex-free lip and cheek retractor allows for everything buccal to the surgical site be more out of the way throughout the procedure. This provides one less issue to struggle with and increases the chance that the clinician won’t nick lips or other tissue inadvertently.

The implants were all placed freehand. The placement of the upper arch had sufficient landmarks to place the implants in a straightforward fashion. The placement of implants 3 and 11 were immediate placements. Depending on surgical technique and implant design, I have found that immediate implant placement can be done in most cases. Implant 3 was placed in the intraseptal bone, and 11 was placed engaging the lingual plate to allow for a screw-retained crown with an access hole at the cingulum. I frequently use Versah^® Densah^® burs to optimize the osteotomy. Even if I have sufficient bone width, I may use a Densah drill as a final drill before implant placement.

When grafting, I nearly always use a placental membrane to cover the bone graft.  I have been using BioXclude^® (Snoais Medical), a resorbable placental membrane, for years, but there are other competing products to choose from. They provide ample amounts of growth factors and have antimicrobial activity, all in a convenient package. It makes for an outcome with a higher chance of success. For sites 3 and 11, I used a particulate cortical allograft to fill in the remaining socket, then tuck the membrane underneath the gingival margins and suture the flaps down to hold everything in place.

For the lower arch, I used a few landmarks and measurements to get the implants in the proper positions and trajectory.  First, I used the CBCT as a starting point to determine the spacing of implants in positions – 19, 20, 21, 23, 26, 28, 29, and 30. I use a Castroviejo caliper to ensure proper spacing when I am placing more than one adjacent implant. I then start with initial drill points and come back and recheck spacing.  For the trajectory, I ensure that the drilling is in the direction of the opposing dentition. For example, in this case, I kept the anterior implant trajectories in line with lingual of the maxillary teeth. This can be confirmed as drilling proceeds with paralleling pins and having the patient slowly occlude. To keep the implants parallel to each other, I use the midline of the face as a type of fiduciary position, then keep the drill straight on while moving into the posterior osteotomies. As I move up in drill diameter, I start again with the anterior osteotomies then go posterior. I would keep on rechecking and correcting the parallelism, if needed, as I go on. Another technique is to place a parallel pin in the center of the ridge at the midline and use that to check parallelism.

In this case, I used Ditron Ultimate™ implants for the following positions — 4.2×11.5 for all the lower implants, 5×8 for 3 and 14, and 4.2×16 for 11. I used this implant for the initial stability the threading design provides and because of the coronal convergence of the implant. This allows for less bone strain at the neck, a sort of platform switch, and anecdotally more soft tissue thickening.

For suturing, my go-to is Glycolon™ 5-0 by Resorba^®, a PGA-PCL copolymer resorbable monofilament suture that usually resorbs in around 3-4 weeks. I find it has sufficient tensile strength and less chance to retain plaque buildup.

Restorative upper arch — Dr. Haroutioun Kotchinian

The upper arch fabrication was accomplished using exocad software to merge preoperative full-smile photos with the final impression, customizing the smile line based on the patient’s extraoral features. Ideal restoration of the upper arch was noted 2 months after surgery. When looking to restore a full arch for a patient, there are many different schools of thought from Kois, Spear, Pankey, and beyond. Many of them have similar principles, but use different terminology. My background came from Spear and the Esthetic, Function, Structure, Biology (EFSB) workflow. In this case, I spent most of the time in the Esthetic section to determine his ideal central display, central angulation, midline location, gingival levels, and buccal corridor.

He had no functional habits that we needed to be concerned about. No jaw pain was present currently or in the past, and no TMD. He did have wear, but we attributed that to progressive tooth loss over time, and the stress that the remaining teeth had to incur as a result of that. In terms of Structure, we chose to use porcelain-fused-to-zirconia (PFZ) crowns because they are highly esthetic, and we need not worry about metal showing over time. Also PFZ crowns generally have higher value than E.max^® crowns as they let less light travel through. This value resulted in a more natural look for our patient as his natural teeth were less translucent. As long as there is adequate thickness of the porcelain, chipping is becoming more rare. Lastly, addressing the patient’s biology, he had adequate bone and probing around the teeth for long term success. His gums were slightly red, but could be controlled through regular prophylaxis. Lastly, his teeth did not need endo as there were no large caries, and our preparation was planned as conservative/normal.

For cases such as this patient, we always take before photos at rest, full smile, and intraoral.

In prepping the case, I first took a preop impression of his current teeth, because I liked the position of tooth No. 8 relative to his face. For an older patient, showing about 70%-80% tooth at a smile is adequate especially for our male patients. He did not want to be too “toothy.” In this particular case because we were going to stage the upper and lower restorations, I simply took a blue-bite impression for his eventual temporaries. I prepped the case doing my best to prep each area of the teeth at the same time, to maintain ideal preps, and angulations. I prep in this order — incisal, buccal, mesial, distal, and lingual. Then I polish using a fine diamond, and extra polish with a slow speed polishing cup. Lastly, I gently pass a fine diamond 859L bur along the margins to open the gums slightly and remove any unsupported enamel.

In preparing for my final impression, I first fabricate the temporaries, using them as custom retraction caps. I placed Hemoban (Dentsply Sirona) and GingiTrac^® (Centrix) on the teeth and placed the temporaries over top of them. This allows me to retract the gums and control bleeding. Although packing cord is the ideal, I found in my experience that this helps save time and provide adequate retraction for a good impression.

For the implants, we used open-tray impression copings. A PA was taken prior to the final impression. For the final impression we use Aquasil^® light body and heavy body in a knockout patented impression tray.

Following the appointment, all this was sent to the lab which digitized the impressions. Using exocad, they were able to place the full smile photo over the preop and prepped scan. This allows us the freedom to design his case for his face without having him in the chair for multiple sessions with temporaries. I usually receive an exocad link which I can conveniently open on my iPhone^®, and analyze for all the parameters we mentioned before. Then I give my feedback to the lab, and they make the necessary changes and send me a link for final approval.

When we inserted his upper arch, there was no guessing as to how it was going to look. We knew the lengths we needed and the spaces in the buccal corridor that needed to be filled, thanks to our digital design. The patient was very satisfied with this step, and was back to Dr. Gammas for his fixed hybrid.

Restorative lower arch — Dr. Iham Gammas

The prosthesis was fabricated for the lower implants using traditional analog techniques, including a final impression, wax bite, and creation of a PMMA try-in. The full-arch fixed dental prosthesis was fabricated out of zirconia, and was delivered 4 months after surgery. The patient was monitored during the healing phase, with adjustments made to the prosthesis as necessary.

The full mouth rehabilitation yielded successful results for this patient, enabling him to regain his chewing function, speech, and esthetics. He reported improved comfort and satisfaction with the new prosthesis, which closely resembled natural teeth in both appearance and functionality. The patient received guidance on proper oral hygiene practices and was advised to schedule regular follow-up visits for ongoing maintenance and monitoring.

In conclusion, full mouth rehabilitation following teeth extraction can significantly enhance the quality of life for patients with extensive dental issues. The use of dental implants and bone grafting provides stability and durability for fixed dental prostheses, restoring essential functions and esthetics. While reimbursement limitations may exist in our community for such procedures, the utilization of a digital workflow allows for accurate teeth design without the need for traditional wax-ups and lab-fabricated provisionals, offering a positive experience for patients while ensuring the smooth operation of our dental office.