#Full-Arch 26. Apr 2016

Mandible restoration with BLT implants and screw-retained abutments in a dental phobic patient with very poor dentition

A clinical case report by Roberto Sleiter and Nathalie Oppliger, Switzerland

The Straumann® Pro Arch solution provides a safe, reliable and less complex treatment option for patients requiring full-arch treatments. Patients and clinicians benefit from the combination of the individualized prosthetics and the surgical advantages of the SLActive®/ Roxolid® combination. The concept of Straumann® Pro Arch is based on a fixed rehabilitation which encompasses the whole procedure from removal of hopeless teeth, immediate placement of four implants and immediate loading of the implants with a temporary bridge. It also includes the treatment planning steps before surgery and afterwards when converting the temporary bridge to the final full-arch prosthesis. (Information by the manufacturer)

Background: The Straumann AID programme

Straumann AID (Access to Implant Dentistry) is a global initiative. The necessary materials for an implant restoration are provided by Straumann free of charge to offer assistance in certain cases to patients who lack the financial means.  In the present case, the patient was in receipt of a disability pension, and therefore had very limited finances. Under these circumstances, an appropriately comprehensive and satisfactory restoration was impossible. Thanks to Straumann AID and the fee waiver by Dr. Sleiter’s practice (surgical and prosthetic treatment costs) and the dental lab (Jenni Dental Laboratory, Fulenbach, Switzerland), we were able to offer this patient a fixed mandibular restoration to re-establish his dental function. A new complete denture was also made for the maxilla.  The final result showed significant improvement, both in aesthetics and function.

Initial situation

A 45-year-old dental phobic patient with very poor dentition, who had not visited a dentist for over 10 years, came to our practice (Fig. 1) requesting remedial work. The complete maxillary denture proved to have an inadequate hold and very poor aesthetic appearance. The patient’s remaining mandibular dentition had multiple caries profunda or cervical caries and apical periodontitis. The patient was a disability pension recipient and therefore his finances were very limited.

Treatment plan

Thanks to the materials provided by the “Straumann Access to Implant Dentistry” programme (“Straumann AID”) and the fact that the authors and the laboratory waived their fees, we were able to offer our patient a complete maxillary denture and a fixed mandibular restoration. First, a new complete denture was made for the maxilla. The patient demonstrated a high level of acceptance during the course of the initial appointments, and therefore the decision was made to fit a fixed mandibular restoration in accordance with the Straumann® Pro Arch concept. This provides for a fixed prosthetic solution which is achieved by extracting the remaining teeth with immediate insertion and immediate loading of at least 4 implants. Due to the above-mentioned very poor condition of the mandibular dentition which is clear in the OPT (Fig. 2) and the questionable prognosis for some teeth, it was decided that the teeth in the lower jaw should be extracted. The treatment is divided into two phases, during each of which the patient receives a temporary restoration and a definitive restoration. The temporary restoration is directly screwed in immediately following implantation, allowing the immediate restoration of function and aesthetics. The definitive restoration involves optimising function and aesthetics after the implants are given time to heal (approximately 2 months).

Surgical procedure

All the remaining teeth in the lower jaw were removed, and bone smoothing was performed at the same time as the implantation (Fig. 3). 4 Straumann® Bone Level Tapered (BLT) implants made of Roxolid® (∅ 4.1, SLActive®, 10mm and 12mm) were used. The 12mm implants were set in regions 32 and 42, and the 10mm implants in regions 35 and 45 (Fig. 4). Thanks to the favourable bone situation in the lower jaw, it was possible to set the implants in parallel (Fig. 4), all of which had adequate primary stability so the decision was made to carry out immediate loading.

“The Patient was able to leave the practice with a temporary fixed restoration within a few hours.”

Prosthetic procedure

A diagnostic splint was used to select the perfect screwed abutments (Fig. 5). In this case, the axes of the implants were so good that no angled abutments had to be used. Thus only 0° abutments were used, which were tightened with 35 Ncm (Fig. 6). In turn, the height of the screwed abutments (available in 1, 2.5 and 4 mm) was selected in accordance with the peri-implant mucosa and the bone level. It was necessary to ensure that the screwed abutments would end up lying epimucosally when the mucosa were adapted. These could be substituted for the final restoration, if the height or angle were not ideal. The protective RC caps (Fig. 7) were manually tightened to the screwed abutments with about 10-15Ncm, and the mucosa were adapted and sutured. The temporary restoration was released amply at a basal level from 35 to 45, following which the complete maxillary denture was used together with a prefabricated silicone bite and the temporary prosthesis filled with silicone (3M ESPE Imprint 4 Bite) in order to determine the intermaxillary relations in the patient’s mouth (Fig. 8). In order to guarantee correct intermaxillary relations, it is important to ensure that the protective caps are not pushed through the silicone. A temporary prosthesis was made for the lower jaw to fit perfectly with the new complete maxillary denture, and also doubled as an operation splint for diagnosis. A bilateral balanced occlusion was selected for the occlusion design, ensuring the functional stability of the complete maxillary denture. Subsequently, the protective caps were removed and an impression of the implants was taken using impression posts. These were screwed directly on to the screwed abutments (Fig. 9). The impression was performed using Impregum (3M ESPE) (Fig. 10). The temporary fixed restoration was incorporated in the lower jaw after just a few hours, following the principle of immediate loading (Fig. 11), with a follow-up appointment to remove the sutures one week later.

Final result

After allowing a 3-month healing period for the implants, an impression of the lower jaw was taken for the definitive restoration. To this end, the impression posts were screwed directly onto the abutments. Bite registration was performed in the conventional manner with a wax rim and the tooth set-up was tried on in wax. Thereafter, a CAD/CAM titanium framework was prepared to support the prosthetic teeth. The passive seat of the framework was assessed before the work was completed. The completed restoration (Figs. 12-13) was tightened with 15 Ncm and the screw channels sealed with Teflon and composite in order to enable possible reintervention. The patient was given instructions on daily cleaning of the fixed restoration with Superfloss and Plack Out gel (Fig. 14). After insertion of the work, there were two follow-up checks, including OPT (Fig. 15). Since then, the patient has attended recall consultations (Fig. 16) twice a year.

Conclusion

Thanks to the Straumann® Pro Arch concept with the new Straumann® Bone Level Tapered implants (BLT), the SLActive® surface (which generates rapid healing of the implants), as well as the large choice of screwed abutments (height and angulation), we were able to provide the patient with an ideal fixed solution within the shortest time possible. Due to the experience of the practitioners and the ideal, close cooperative relationship with the dental laboratory, all the prerequisites for a smooth and successful process were in place, so the patient was able to leave the practice with a temporary fixed restoration within a few hours. Overall, from insertion of the implant to the second follow-up check on the final restoration, the patient only attended 8 appointments and within 5 months he was fitted with his final maxillary and mandibular restoration.