Media & news

Veneering options – part 2

by: Professor Stefan Holst

Read the second part of Professor Stefan Holst's article on veneering options for fixed implant-retained restorations. This time, you get a follow-up presentation on state-of-the-art techniques and materials.

In this issue of Nobel Biocare News, Professor Stefan Holst continues to present restorative options for manufacturing definitive restorations with NobelProcera, each of which can be adapted specifically to the needs of the patient and the preferences of the treatment team.

The following case reports from some of our skilled partner clinicians underline the versatility and display the functional and esthetic outcomes that can be achieved with the NobelProcera Software. To view the complete treatment sequences online, please see the “More to explore” section at the end of this article. 

Case 1

Dr. Ferdinando D’Avenia and Master Dental Technician Cesare Ferri of Parma, Italy, utilized a NobelProcera Implant Bridge Titanium veneered with acrylics to accommodate for the clinical situation and the expectations of the patient: A 55-year-old man, suffering from bi-maxillary severe bone atrophy, presented with discomfort and chewing deficiencies. He was wearing two severely worn, 20-year-old complete dentures and requested implant-supported fixed restorations. 

Following diagnostic and radiographic examinations, the definitive treatment plan compensated for the extensive resorption of alveolar ridges (hard- and soft-tissue architecture) via prosthetic means. In addition to functional and esthetic rehabilitation, the patient needed a cost-efficient solution that would not require high maintenance costs.

To meet his needs and expectations, the treatment team decided to go for the following solution: Four NobelActive implants were placed in both the maxilla and the mandible according to the All-on-4® concept. Treatment planning and execution were carried out with NobelClinician/NobelGuide technology, and an immediate provisional restoration was provided. To reduce additional costs for the patient, the existing dentures were transformed into an immediate, screw-retained provisional (readapted to a correct VDO). Following a four-month healing period to allow for osseointegration of the fixtures, the provisional was subsequently replaced with definitive restorations, i.e. NobelProcera Implant Bridge Titanium veneered with conventional denture teeth and cold-cure acrylics. (See figures 1 through 7.)

Why this approach?

The team’s rationale for selecting this approach has to do with a number of clinical and technical advantages. First of all, the titanium framework represents an economical solution, which also demonstrates beneficial biomechanical properties in combination with Nobel Biocare’s Multi-unit Abutments (MUA). Not only does this solution provide excellent peri-implant, soft tissue biocompatibility, it is also associated with a straightforward handling protocol for both the clinician and the dental technician. 

MUAs provide ease of use through accessibility. At the same time, their use supports biologic stability of the peri-implant tissues, as this critical interface remains undisturbed during the change from a provisional to final restoration (e.g. abutment-level impression and fixation of the definitive framework). From a technical and longevity perspective, the performance of the chemical bond between titanium and acrylic has ample scientific background, can be easily achieved, and is stronger than a zirconia-ceramic bonding. 

What’s more, costs for the patient can be significantly reduced through material selection and the choice of prefabricated standard acrylic denture teeth. In fact, there are any number of time- and cost-saving production steps in the dental laboratory when this option is chosen. Reduced maintenance costs in case of late prosthetic reintervention can be expected and most repairs can be performed intra-orally. Finally, this restorative approach produces highly esthetic results thanks to an optional outer layer of composite resin that can be added after a cut-back of the denture teeth (depending on the esthetic needs and expectations of the patient).

Case 2 (Figures 8-12)

Drs. Mario Imburgia and Giovanni Cricchio, and Ceramicists Angelo Canale and Angela Giordano of Italy chose a NobelProcera Implant Bridge Zirconia, manually veneered with feldspathic ceramics as a solution in their daily routine: The patient presented was a 64-year-old woman who was affected by generalized severe periodontal disease. She had been wearing an upper partial removable denture for approximately 10 years prior to her first consultation for implant-supported restorative treatment. 

Her chief complaint was discomfort and lack of masticatory efficiency and esthetics. Migration and increased mobility of her teeth had resulted in altered speech and contributed significantly to her sense of insecurity.  

She made it clear that esthetics were as important as the functional outcome. She wanted to regain a natural and esthetically pleasing appearance without the “Hollywood smile” effect. The treatment team had to comply with two conditions: 1) The patient did not want to be subjected to invasive surgical procedures, and  2) she was unwilling to wear removable dentures during the provisional phase. To accommodate both needs and stipulations, the treatment team decided to go for the following solution:

Implant treatment planning in both the maxilla and mandible was carried out using NobelClinician Software. Post-extraction, immediate flapless implant placement was done with a two-piece radiographic guide, after which an immediate provisional restoration was provided. 

Fixed implant-supported zirconia bridges (NobelProcera Implant Bridge Zirconia) were produced for the definitive restoration in order to ensure high comfort, stability and good esthetics. In the mandible, five implants were placed and restored with screw-retained, single tooth restorations and a screw-retained implant bridge (zirconia).

Rationale behind the choice

The team chose this combination of zirconia frameworks and veneering ceramic for a number of reasons. From extensive earlier experience, they knew that this option would allow them to obtain an optimal esthetic result, achieving natural-looking color and translucency in the individual dental restorations while elsewhere preserving soft tissue volume and architecture.

With this combination of materials and techniques, they also knew that they would be using a highly biocompatible material to make a prosthetic restoration that would provide excellent integration and stability of the peri-implant tissues. The team also chose this combination in order to obtain an optimal esthetic result in a fully customizable prosthetic solution; one that would be, at the same time, both simple and retrievable. 

From a technical point of view, the team points out, “This choice has allowed us to maintain an excellent fit of the framework due to CAD/CAM technology and the high stability of zirconia during the firing of the veneering ceramic.” Finally—and not least of all—they chose this combination of zirconia and veneering ceramics because of the NobelProcera Software features, which allow for fully customized frameworks, designed to support the veneering materials for stable, long-term results.

Case 3

Professor Alessandro Pozzi and Master Dental Technicians Paolo Paglia and Alberto Bonaca of Rome, Italy, were presented with the following case. The patient, a 62- year-old lady, had been wearing a porcelain-fused-to-metal restoration in the upper jaw since the late 1980s. She presented with a failing dentition in both the maxilla and mandible and a moderate bone resorption pattern.

After some discussion, it became clear that she was looking for full mouth rehabilitation and requested a minimally invasive approach that would provide natural-looking, lifelike  prosthetic emergence from the gingival tissue. No artifical gingiva was acceptable for the patient. Because of the daily administration of oral anticoagulant medications, a minimally invasive surgical approach, avoiding any major bone grafting procedures, was medically essential.

References

Monolithic lithium disilicate full-contour crowns bonded on CAD/CAM zirconia complete-arch implant bridges with 3 to 5 years of follow-up.

Pozzi A, Tallarico M, Barlattani A.J Oral Implantol. 2013 Nov 4. [Epub ahead of print]

More to explore:

To learn more about NobelProcera, please click here.

To learn more about the NobelClinician Software, please click here.

Looking to add to your skill set? Check out Nobel Biocare's global course catalog to find a training program near you.