The Immediate Provisional Hybrid

A growing patient population is missing some or all of their teeth. In the past, the only treatment option for patients whose dental health had deteriorated to this extreme was a removable partial denture or a full denture.
Unfortunately, the replacement of natural teeth with dentures is commonly associated with some undesirable physical and emotional changes. Patients who had all of their teeth removed and replaced with an immediate denture frequently found the abrupt transition very difficult. As soon as the teeth are removed, the constant stimulation to the bone once provided by chewing no longer occurs, and the bone that once supported the teeth and soft tissues begins to resorb (Figure 1).
Over time, changes in the mouth can cause dentures to fit poorly, creating uncomfortable pressure on gum tissues. Many denture wearers experience difficulty with maintaining a proper diet because eating is associated with denture pain or discomfort. Dentures can also interfere with speech and cause social embarrassment when they slip unexpectedly. Overall, in the long-term, most patients have found dentures to be a less than satisfactory solution.

EARLY IMPLANT METHODS

Figure 1. Pretreatment photo.

Figure 2. Implants with temporary abutments.

Dental implant technology has undergone significant evolution. In the early days, the dentist refracted the gum tissue to visualize the bony anatomy. This visual assessment and strategic implant placement was critical in order to avoid damaging nerves and to ensure the proper position and function of the final replacement teeth. (Visual assessment yields less predictable results when there is extensive bone loss, or when multiple implants are planned.)
The implants were then left undisturbed for 6 to 9 months to allow the titanium implant posts to form a secure bond with the jawbone. During the 6 months (or so) while the titanium bonded to the bone, the patient either went without teeth or continued to wear the old dentures. In a second procedure, the implants were uncovered and the posts were attached. The teeth were then affixed to those posts.
With the development of dental implants, dentists are able to offer a superior alternative to the conventional partial or full denture. Additionally, new improved implant procedures have been developed and refined in response to the demand for greater accuracy and shortened treatment time. These new procedures enable the restoring dentist to place dental implants and attach replacement teeth in the same visit.

CASE REPORT
Immediate Provisional Hybrid Technique

Figure 3a. The patient’s existing denture was modified.

Figure 3b. The surgical guide.

Figure 3c. Predrilled holes in denture.

Figure 4. Fit of the temporary denture was evaluated.
Figure 5. Processing the denture to the abutments. Figure 6. The final temporary hybrid.
Figure 7. The immediate provisional hybrid, shown in place on the day of surgery. Figure 8. Completed case.

For our patient, the treatment process began by making a denture: the same type that is typically created when teeth are extracted or existing dentures are replaced. This is to be converted into a temporary hybrid denture at the time of implant surgery. The surgeon then placed dental implants, installed temporary abutments (Figure 2), and the extraction sites were sutured to close the tissues.
Next, the restoring dentist modified the new denture to fit over the temporary abutments (Figure 3a). Although there is a short learning curve associated with this step, it becomes very easy after completing a few cases. This step can be completed ahead of time if the implants are placed with an implant placement system such as NobelGuide (Nobel Biocare). A presurgical working model was made using a surgical template, and the holes were predrilled prior to the day of surgery (Figures 3b and 3c).
After the denture was properly fitted over the temporary abutments (Figure 4), the denture was processed in the mouth to the abutments. First, the access holes were plugged with plastic Q-tip rods to prevent acrylic from closing off the opening to the abutment screw. Then, the denture was processed to the abutments using fast-set denture repair acrylic. This was done by placing the uncured acrylic in a plastic syringe and expressing it into the opening in the denture next to the abutments (Figure 5). The denture was held firmly in place until the acrylic cured completely. After it was cured, the Q-tip plugs were removed and the denture was converted into an implant-supported hybrid denture. All excess acrylic, and most of the denture flange, was removed to make a high-water-type appliance. After adjusting the appliance, the underside was polished and glazed for a smooth finish that would facilitate proper hygiene (Figure 6).
The hybrid was then attached back to the implants. The screws were torqued to 35 Ncm, then the access holes were filled with cotton and Cavit (3M ESPE).
The patient left the day of surgery with a fixed-hybrid denture (Figure 7) that served him for 3 to 4 months while the implants completely integrated.
During this time, we addressed any issues of occlusion and function. The patient was restricted to only fork-mashed food for the first 3 months, after which he was able to resume eating normal food.
The final restorations were delivered at 4 months post surgery, and the patient was extremely pleased with the final outcome (Figure 8).


Dr. Phillips earned his degree in dentistry from University of Texas Dental School. He is an active member in the American Academy of Cosmetic Dentistry, the ADA, and the Texas Dental Association. He can be reached at (817) 361-1999 or via e-mail at docbp@aol.com

Disclosure: Dr. Phillips reports no conflicts of interest.