Initial situation

A 65-year-old female patient with medical history of Diabetes Type II controlled with medication presented to the clinic with severe esthetic and functional problems due to complete edentulism as a result of generalized Stage IV Periodontitis (Fig. 1-3). Her chief complaint concerned the impairment with chewing all type of food and compromised esthetic appearance.

Clinical and CBCT digital analysis revealed alveolar ridge deficiency by cause of remaining teeth extraction several months before (Fig. 4-7).

Treatment planning

Based on the initial intra oral and extra oral clinical assessment, CBCT digital analysis, the patient’s functional and esthetic requirements and financial aspects, a definitive treatment planning was selected. The proposed treatment plan was the prosthetic reconstruction of both the maxillae and mandible with prosthesis that the patient could remove and were easily to maintain and simultaneously fulfilling the high functional and esthetic expectations. Therefore, implant supported fixed/detachable maxillary overdenture with a palate-less design and implant-retained overdenture with Novaloc® System were selected as final restorations.

The fabrication of transitional full acrylic complete dentures (Fig. 8 and 9) with customized teeth and the proposed functional and esthetic parameters was carried out in order to set the final tooth position before implant placement. This “restoration-driven” concept aims to optimize implant planning and placement according to the desired prosthetic reconstruction.

Transitional dentures were duplicated into clear radiographic guides with gutta-percha points. These were placed in the potential areas of interest and served as surgical templates as well. (Fig. 10).

Surgical procedure

After local anesthesia, a crestal incision in the maxilla was performed slightly palatal to preserve the attached gingiva and a full thickness flap was raised with the purpose of reducing the alveolar ridge to create an adequate platform assuring the vertical space required for the final prostheses (Fig. 11). Following the osteotomy, five implants (four Straumann® Bone Level Tapered   Ø3.3mm, length 12mm , Roxolid SLActive and one Bone Level Tapered Ø4.1 mm, length 8 mm , Roxolid SLActive) were placed in straight position well distributed across the arch and left with closure screws (Fig. 12). The primary wound closure was performed with a modified continuous sling suture using non-resorbable PTFE monofilament suture material.

After 4 weeks, the second surgery consisting in the placement of 4 narrow-diameter implants (Straumann® Bone Level Tapered Ø3.3mm, length 10mm, Roxolid SLActive)  in the mandible located in inter-foraminal distribution (canine and second premolar) were placed in straight position, avoiding important anatomical structures in the molar sites and the severe reabsorbed anterior mandible (Fig. 13 and 14).

The implants were left with closure screws for a two-phase submucosal healing (Fig. 15) and conventional loading protocol was selected in both the maxilla and mandible according to the ITI Consensus Statement on loading protocols for implant supported over dentures in edentulous jaws. After 8 weeks of healing, a second surgery was performed to uncover the implants and placing healing abutments preserving the attached gingiva (Fig. 16 and 17).

Prosthetic procedure

The first step was to accurately transfer the implant 3D position to the laboratory through conventional impressions with open tray technique using polyvinyl siloxane and customized trays. Cast models with implant analogs were obtained, scanned, and digitized; from this point, a complete digital workflow for the production of the final restoration was employed. Posteriorly, the craneomandibular jaw relation was registered using an specific system (Udo Plaster’s Plane System, Zirkonzahn, Gais, Italy) which is based on the patient’s natural head position and the Ala-Tragus plane, allowing an accurate transfer of this information to the physical and virtual articulator.

Eventually, the patient’s facial 3D recording was taken using an optical face scanner with a bite plate for image merging and 3D patient analysis (Fig. 18). The application of a 3D face scan is an important tool that provides the clinician and laboratory with valuable patient information and better communication with the patient.

Following data acquisition (with laboratory scanner) and merged in the CAD software, the digital design process of the final restorations was initiated. The CAD software allows full control of the prosthesis with 3D data of the esthetic and functional parameters verifying occlusal contacts and excursion movements in the virtual articulator (Fig. 19-22).

For the maxillary arch, 5 monolithic zirconia telescopic crowns were designed and milled according to the previous digital set up (Fig. 23-27) and cemented onto Straumann® Variobase abutments (four Straumann® Variobase NC Ø3.8mm, AH 3.5mm, GH 1mm and one RC Ø4.5 mm,  AH 3.5mm, GH 1 mm). The final prosthesis consisted in an overdenture CADCAM base material milled in ceramic reinforced PEEK with anatomic reduction to receive customized monolithic ceramic denture teeth (Fig. 28-31). Lastly, indirect pink veneering composite was used to reproduce the gingiva anatomy (Fig. 32-35).

The telescopic crowns were screwed and torqued at 35 Ncm, the access holes were blocked with PTFE and the final prosthesis was incorporated (Fig. 36 and 37).

The fabrication of the final restoration for the mandible included a milled implant retained overdenture in pink PMMA denture base material with CADCAM polymer denture teeth customized with layering composite. Four straight Straumann Narrow Crossfit Novaloc® abutments (Ø3.8mm and height 3mm) were selected as the retention system for final prosthesis (Fig. 38 and 40). These abutments have the advantage of requiring minimal vertical prosthetic space, high patient satisfaction due to excellent and long-lasting retention properties and significantly higher wear resistance in comparison to other stud type attachments.

The intra-oral pick up process of the abutments was performed using dual-cure self-adhesive pink composite (Fig. 41-44). Subsequently, finishing and polishing were made and PEEK Novaloc® retention inserts with light retention force (white color) were placed.

Treatment outcomes

Final intraoral and extraoral views 6 months postoperative illustrate the very pleasant and natural result achieved (Figs. 45-50). The patient is very satisfied with the esthetic and more important functional outcome reporting the ability to eat and chew different types of food describing as a life-changing experience.