Facilitating Treatment Utilizing Pre-Existing Implant Components

In an article about how to use pre-existing implants in redesigning a full arch reconstruction, we discussed how the treating team is often torn between keeping or removing pre-existing implants—and the importance of doing a thorough assessment to decide whether pre-existing implants are suitable to be reincorporated into a new comprehensive restorative design or not.

We discussed the importance of assessing:

• Biologic parameters (bone loss/presence of active infection)
• Structural parameters (type of implant, integrity of connection, etc.)
• Esthetic parameters (4Dimensional implant position)

If and when you decide to carry on and utilize pre-existing implants, your next crucial decision involves figuring out if the implant-supported components—including abutments, framework, screws—are suitable to be reutilized during the upcoming phase of treatment.

Expediting provisionalization with pre-existing implant components

The case below illustrates a great clinical example of when such components can be of substantial help during the provisionalization phase of a comprehensive treatment.

Utilizing the pre-existing substructure of two implant-supported fixed partial dentures allowed our team to expedite provisionalization as well as mitigate the cost involving prosthetic components.

The patient presented to our office dissatisfied with the overall esthetics and function of the maxillary anterior teeth, she had 2 maxillary implant supported screw retained FPD and upon further clinical examination the maxillary anterior teeth that were present had extensive structural and biological breakdown and were deemed unrestorable (Fig. 1 – Fig. 6).

Upon extraoral and intraoral careful examination, it was decided to change the overall contours to provide a more pleasing/harmonious result, as there were clearly noticeable discrepancies in both the incisal plane as well as gingival outline.

Thus, a wax-up of the maxillary arch was made and a shell provisional was fabricated in the lab (Fig. 7). As in any comprehensive treatment, the next phase of therapy entailed the provisionalization phase.

Being that the patient presented with five external hex implants (Fig. 8) with an overall acceptable distribution within the maxillary arch to support a full arch splinted provisional restoration, the question here was this: Can we utilize some components of the pre-existing fixed partial dentures to aid such provisional restoration?

If the answer was no, we would've then needed to buy five temporary abutments and do a pick-up protocol during the full arch provisional shell reline or fabricate a new provisional in the laboratory.

In this case, however, we were required to redesign the full arch reconstruction. Nonetheless, we were able to strip the layering ceramics from the framework and keep the metal frameworks along with their corresponding screws as the means to connect the provisional to the implants in the sturdiest and relatively effortless approach (Fig. 9).

We then proceeded to opaque the metal frameworks and secured them back in place, the coronal portion of the three natural teeth was amputated to carry out the reline of the provisional shell, letting it to set intraorally, thus ensuring that the frameworks were then captured within the acrylic reline.

This not only provided the means to connect the provisional to the implants, but the framework provided a robust structural reinforcement which ensured biomechanical stability during the healing and osseointegration phase of the newly placed implant (Fig. 10 – Fig. 14).

Moreover, once the roots of the anterior teeth where extracted, the provisional was secured in its place and it served as a sturdy and stable surgical template which allowed for an ideal 4-dimensional placement of the anterior implant—mesial-distal, buccal-lingual, apical-coronal and angulation (Fig. 15 and Fig. 16).

The implant supported provisional was finalized and polished and it was delivered to the patient after the extractions of the remaining maxillary teeth was performed and the implant was placed in the position of #8 (Fig. 17 and Fig. 18). It can be appreciated that the esthetic concerns of the patient were addressed during the wax-up and successfully incorporated in this new provisional (Fig. 19).

After a few weeks, the patient returned for a post-op appointment. This appointment made it clear that the provisional was performing well and the soft tissues were supported in the pontic areas (Fig. 20).

Finalizing comprehensive rehabilitation

As mentioned earlier, an additional implant was placed in the area of tooth number 8, immediately after extraction. Since there was enough support from the previous implants, our team decided to utilize a delayed loading approach and the area was managed with ovate pontics.

Once time was allotted for osseointegration (10 weeks) we proceeded to perform a minimally invasive uncovering protocol utilizing an iPlus Waterlase unit from Biolase. A temporary abutment was secured onto the implant followed by radiographic verification that it was fully seated.

The provisional restoration was then perforated at the site of the implant and the temporary cylinder was then adjusted, opaqued and picked up utilizing light polymerizing flowable composite utilizing the same technique described earlier in this article.

At this point, the transmucosal contours of the provisional were carefully conformed utilizing a light polymerizing flowable composite, followed by polishing with rubber wheels. Once the gingival topography was stable, an implant level impression was made and a prototype of the definitive restoration was fabricated.

The old mandibular porcelain fused to metal crowns were removed on the mandibular anterior teeth and a provisional restoration was relined and trimmed. The posterior teeth were minimally prepped for onlays and impression and jaw relation records were taken, allowing the ceramist to finalize the comprehensive reconstruction.

Ricardo Mitrani, D.D.S., M.S.D., is a member of Spear Resident Faculty.