Converting complete dentures to a full arch implant-supported solution is an increasingly popular approach to treat patients with immediate loading protocols.

Converting a pre-existing removable denture (in the case of an edentulous patient) or an immediate denture (in the case of a patient with terminal dentition) to a fixed screw-retained provisional prosthesis is accomplished by doing an intraoral pick up of temporary cylinders, which are secured to transmucosal abutments (or SRA abutments). Sometimes the treating team may choose to secure the temporary cylinders to the head of the implant and avoid an abutment-level connection.

Wide windows aid the prosthesis path of insertion

This conversion technique requires identifying within the intaglio surface of the removable appliance the concentric contour of the implant, securing a healing abutment, and utilizing silicone jaw registration material to identify the implant's position. Then, silicone is removed, and the denture is hollowed in that precise site (opening a window) through which the temporary cylinder is captured with either auto polymerizing polymethyl methacrylate or dual-cure composite material.

Since the prostheses are supported by at least four osseointegrated implants, it is advisable to create wide windows facilitating the draw (path of insertion) of the prosthesis, so the cylinders don't bind, potentially altering the position of the denture during pick up. But wider windows guarantee that pick-up material will contact and capture 360-degrees around the temporary cylinder, which ensures a sturdy pick-up to withstand the forces of mastication and avoids potential fractures of the provisional prosthesis during the osseointegration phase.

However, there can be a downside to utilizing a wider open window. A portion of the anatomical occlusal surface can be lost while hollowing out concentric windows. But you can rebuild any lost occlusal anatomy, and ideally, you should because it's more comfortable for the patient and it facilitates achieving occlusal contact situated axially or on top of the cylinder (the preferred location of an occlusal contact).

Optimizing occlusal contours freehand and with a silicone matrix

Below I describe the freehand application of composite material to optimize the occlusal contours of a hybrid immediately loaded provisional restoration and how to facilitate occlusal reconstruction by obtaining a silicone matrix before the occlusal anatomy is modified.

Frontal and occlusal views of the immediately loaded maxillary implant-supported provisional prosthesis during the pick-up process. Note the wide-open areas around the temporary cylinders.
Figure 1: Frontal and occlusal views of the immediately loaded maxillary implant-supported provisional prosthesis during the pick-up process. Note the wide-open areas around the temporary cylinders.
Occlusal views of the prosthesis after the pick-up technique and after the composite freehand technique to reconstruct the loss of anatomy.
Figure 2: Occlusal views of the prosthesis after the pick-up technique (L) and after the composite freehand technique (R) to reconstruct the loss of anatomy.
A before and after view of the composite freehand technique reconstructing the loss of anatomy.
Figure 3: A before and after view of the composite freehand technique reconstructing the loss of anatomy.
Frontal and intaglio view of the provisional prosthesis.
Figure 4: Frontal and intaglio view of the provisional prosthesis.
Immediately loaded provisional prosthesis after surgery and insertion.
Figure 5: Immediately loaded provisional prosthesis after surgery and insertion.
Frontal and occlusal mandibular view during initial presentation.
Figure 6: Frontal and occlusal mandibular view during initial presentation.
Immediate mandibular denture with clear-acrylic duplicate for use as a surgical guide.
Figure 7: Immediate mandibular denture with clear-acrylic duplicate for use as a surgical guide.
Silicone matrix is fabricated before modifications are made.
Figure 8: Silicone matrix is fabricated before modifications are made.
Conversion prosthesis procedure with wide-open areas for pick-up.
Figure 9: Conversion prosthesis procedure with wide-open areas for pick-up.
Mandibular immediate denture after the pick-up procedure.
Figure 10: Mandibular immediate denture after the pick-up procedure.
PMMA is injected into the silicone matrix, and the provisional is repositioned to recreate the occlusal surfaces with acrylic.
Figure 11: PMMA is injected into the silicone matrix, and the provisional is repositioned to recreate the occlusal surfaces with acrylic.
A view before and after the silicone matrix technique.
Figure 12: A view before and after the silicone matrix technique.
Frontal view of the implant-supported provisional prosthesis.
Figure 13: Frontal view of the implant-supported provisional prosthesis.
Frontal and occlusal view of the implant-supported provisional prosthesis.
Figure 14: Frontal and occlusal view of the implant-supported provisional prosthesis.

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


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Comments

Commenter's Profile Image Myrna C.
September 24th, 2022
Beautiful work Dr. Mitrani, thank you so much for sharing these photos.