#Full-Arch 28. Aug 2023

Digital Technology for Complete-Arch Implant Prostheses

A clinical case report by Edmond and Armand Bedrossian, USA

Digital technological improvements in recent years have transformed several industries, including implant dentistry. This novel methodology has several advantages over standard procedures, including increased efficiency, accuracy, and patient satisfaction. (1-3)

Furthermore, this approach enables the development of customized prostheses supported by conventional and zygomatic implants. The Straumann® Zygomatic Implant System provides a predictable, fixed immediate restoration option that does not need bone augmentation, providing a dependable treatment for patients with significant maxillary bone loss and presumably hopeless circumstances.4

Additionally, digital technology improves communication and collaboration between the patient, dental team, and laboratory. The computerized process enables seamless information sharing and virtual treatment planning, resulting in a coordinated and exact approach to the production of complete-arch implant prostheses.

The following case report was planned and executed using the DIGILOGTM concept, which is a hybrid of digital and analog workflows combining the best features of both approaches. This concept allowed us to have optimal communication with the implant team and our patient, who received two complete-arch implant prostheses. Two Straumann® Zygomatic Implants and two Straumann® BLX Implants were placed in the maxilla, and four Straumann® BLX Implants were placed in the mandible.

Initial situation

A 57-year-old systemically healthy, female non-smoker with no relevant medical history came to our clinic and stated: “I am unable to eat without pain, and I have absolutely no confidence or pride in my smile and overall appearance.” She also noticed flaring and progressive spacing of the front teeth and complained of food impaction. She desired a full mouth fixed rehabilitation and wanted to improve the position of her teeth to regain the confidence to smile.

No abnormalities were found during the extraoral examination. The patient presented a low smile line. The intraoral examination revealed a terminal dentition due to generalized periodontal disease. She presented severe resorption of the bilateral posterior maxilla (Fig. 1). The radiographic examination showed generalized alveolar bone resorption with vertical bone defects (Fig. 2).

Following the radiographic and clinical evaluation, the patient was classified as complex in terms of the surgical and prosthodontic SAC classification (Fig. 3). The SAC classification aids in assessing the degree of difficulty and risk associated with implant-related rehabilitation.

Treatment planning

Our patient was presented with various treatment plans encompassing both removable and fixed rehabilitation options. Among these, the patient was informed about the DIGILOG™ treatment concept, which merges analog and digital workflows to create immediate and definitive dentures. After considering the available choices, the patient chose to proceed with this option.

The DIGILOG™ concept was developed in collaboration with Dr. Gurries. This approach enables the surgeon to communicate with the prosthodontist, using digital technology and analog surgical treatment, allowing predictable treatment outcomes.

Two steps were included in our workflow for immediate full-arch treatment using the DIGILOG™ concept:

  1. The printing of the complete denture prototypes to assess the peripheral borders, vertical dimension, esthetics, phonetics, and occlusion.
  2. The scanning of the intaglio, peripheral borders, and occlusion, and transfer of the resulting information to the laboratory to finalize the peripheral borders and vertical dimension of occlusion (VDO), before milling the monolithic final denture.

The coDiagnostiX® software was used to plan the analog surgical placement of two Straumann® Zygomatic Implants and two Straumann® BLX Implants for the maxilla, and four Straumann® BLX Implants for the mandible. The chosen protocol was immediate loading following an atraumatic extraction of the residual teeth while protecting the remaining bone (Figs. 4,5).

The patient's stereolithography (STL) file was generated and sent to the in-house lab to create a three-dimensional printed model for the surgical planning, allowing us to obtain the “Model Surgery” (Fig. 6).

The surgical approach was planned graftless to avoid complex procedures for implant placement and decrease morbidity and costs for the patient. On the same day, the immediate milled dentures were delivered. Six months later, two complete fixed, digitally fabricated, full-arch implant prostheses were placed.

In summary, the treatment workflow was as follows:

  1. Data acquisition for immediate denture fabrication.
  2. Implant surgery and immediate PMMA prostheses.
  3. Digital approach for the design and manufacture of the final prostheses.
  4. Delivery of final zirconia prostheses and occlusal guard 6 months after implant surgery.

A Center of Dental Education (CoDE) is part of a group of independent dental centers all over the world that offer excellence in oral healthcare by providing the most advanced treatment procedures based on the best available literature and the latest technology. CoDEs are where science meets practice in a real-world clinical environment.


Surgical procedure

Before surgery, an intraoral scanner was employed to acquire the digital data for immediate denture design (Fig. 7). The teeth were digitally removed, and digital dentures were created. The data of the virtually constructed dentures was subsequently transmitted to a milling machine for the fabrication of immediate monolithic polymethyl methacrylate (PMMA) prostheses.

The treatment was carried out under local anesthesia with lidocaine 2%:100,000 epinephrine. A full-thickness mucoperiosteal flap with a crestal incision was raised. The implant beds were prepared with the Straumann® Surgical Cassette, and two Straumann® BLX Implants Ø 4.5 mm, SLActive® 10 mm, Roxolid® and two Straumann® Zygomatic Implants, Ø 4.3 mm, L 40 mm, Ti were placed in the maxilla (Fig. 8). Following the same protocol, four Straumann® BLX Implants Ø 4.5 mm, SLActive® 10 mm, Roxolid® were inserted in the mandible. Straumann® Screw-Retained Abutments (SRA) were positioned onto the implants (Fig. 9).

The mucoperiosteal flap was carefully adapted and sutured. Temporary screw-retained prostheses were then placed on the day of the surgery (immediate loading protocol) (Fig. 10). The prostheses were checked for areas of excessive pressure and adjusted.

The patient was given postoperative and oral hygiene instructions. Two weeks following surgery, the sutures were removed, and the healing was uneventful.

Prosthetic procedure

The patient received follow-up controls and, at six months after implant placement, an indirect digitization of the back-poured master cast was done, allowing for superimposition of the tooth position onto the implant position (Fig. 11).

The final tooth set-up and occlusal scheme were done digitally to ensure optimized esthetics and function (Fig. 12). Once everything was digitally verified, we proceeded to create the final zirconia prostheses with porcelain-layered gingiva (Fig. 13). The occlusion was checked and, additionally, a 3D printed occlusal guard was given to protect the implant-supported denture, acting as an absorber and distributor of occlusal forces (Fig. 14).

A panoramic radiograph was taken to monitor the health around a dental implant at prosthesis delivery (Fig. 15).

The prostheses fulfilled the patient's expectations and needs. The patient was delighted with the major change in her smile and quality of life (Figs. 16,17).



Treatment outcomes

Digital and analog can be seamlessly integrated to enable a comprehensive assessment and treatment. Optimal planning and meticulous examination play pivotal roles in determining the outcomes of the treatment. A personalized surgical approach is imperative to address the diverse needs and requirements of each individual patient.

On the same day of surgery, employing the principle of immediacy and without the necessity for guided bone regeneration (GBR), an outstanding functional and esthetic outcome was accomplished with two Straumann® BLX Implants and two Straumann® Zygomatic Implants in the maxilla and four Straumann® BLX Implants in the mandible.

Six months later, the patient was also very pleased with the retention and esthetics of the final complete-arch implant prostheses. The clinical and radiographic evaluation yielded stable and favorable results, indicating positive progress. The patient was provided with hygiene instructions and scheduled for regular check-ups to ensure ongoing care and monitoring.

Author’s testimonial

The DIGILOG™ concept, using digital technology to complement fundamental surgical and prosthetic principles along with scientifically designed armamentarium allows for treatment of this case with a predictable outcome.

References:

  1. Menini M, Setti P, Pera F, Pera P, Pesce P. Accuracy of multi-unit implant impression: Traditional techniques versus a digital procedure. Clin Oral Investig 2018;22:1253-62.
  2. Vandeweghe S, Vervack V, Dierens M, de Bruyn H. Accuracy of digital impressions of multiple dental implants: an in vitro study. Clin Oral Implants Res 2017;28:648-53.
  3. Cappare P, Sannino G, Minoli M, Montemezzi P, Ferrini F. Conventional versus digital impressions for full arch screw-retained maxillary rehabilitations: a randomized clinical trial. Int J Environ Res Public Health 2019;16:829.
  4. Tuminelli FJ, Walter LR, Neugarten J, Bedrossian E. Immediate loading of zygomatic implants: A systematic review of implant survival, prosthesis survival and potential complications. Eur J Oral Implantol. 2017;1:79-87.