PMMA Hybrid: A Solution for Edentulous Patients

Periodontal disease and dental caries are the main causes of edentulism worldwide. While this issue affects predominantly an older demographic, it is linked to sociodemographic factors, including lower incomes, certain lifestyles, and other systemic issues.

There are many different options today to rehabilitate patients suffering from tooth loss. One of the leading treatments is fixed implant-supported restorations.

Implant-Supported Restorations

Fixed implant-supported restorations provide patients with a stable, secure solution to combat tooth loss. In addition, these restorations provide facial support and help to minimize facial sagging. Implants help to keep the jawbone healthy by helping to promote bone growth.

The benefits of this type of restoration include:

• Provides more functionality than traditional dentures
• Provides more comfort than traditional dentures
• Patients have more security with these types of restorations
• Promotes healthier bone growth
• Creates better mastication
• It is a more aesthetic option

There are several different types of fixed implant-supported restorations from which to choose. Understanding which ones are best suited for an individual case is critical in ensuring that the case will be successful.

Case Study

This case came to Burbank Dental Lab from Dr. August de Oliveira. The patient is a homeless man who was part of a program to provide restorative dentistry to those less fortunate. This patient is an older man who has worn several prostheses, including dentures, a zirconia hybrid, and a metal frame-reinforced hybrid. Unfortunately, this patient has a history of breaking these restorations (see the image shown below). The challenge here was to find a restorative option that would service this patient in the best possible way.

This case was completed with a completely digital workflow. The scans were done using DESS titanium scan bodies (see image below).

The system used to scan the case was the CEREC Primescan. Both arches were scanned to capture the relevant data, including implant locations (see image below).

It was determined that the best restorative option for this patient would be to fabricate a CAD titanium bar with a PMMA hybrid overlay. One of the key factors in choosing this material was that it would be easy to repair if the patient had any issues with it. The PMMA allows for easy repairs and offers this patient a more reliable prosthesis.

Other restorative options for implant-supported restorations include:

SmartComposite Hybrid

• Flexural strength of 1000 MPa
• Natural Esthetics
• High levels of translucency
• Extremely durable
• Feels remarkably like natural dentition

ZIRMAX M

• 480 MPa compressive strength
• Monolithic will not dislodge like denture teeth
• Easy to polish
• Lightweight
• Can be repaired with composite intraorally
• Reduces stress to implants
• Wears at about the same rate as natural teeth

SMART 1 Titanium Implant Bar

SMART 1 titanium implant bars were designed and milled. The Burbank Dental Lab SMART 1 implant bars are designed to distribute occlusal loads evenly between the implants.

These bars are milled on a 5-axis computer numerical control (CNC) machine. The CNC technology takes numerical data that represents instructions to be carried out by milling machinery. The accuracy of a prosthesis milled using a five-axis CNC machine ensures a passive fit every time.

Next, plastic overlays were fabricated to be placed over the bar to check both the bite and the midline (see below image).

PMMA Fabrication

The next step was the design of the PMMA overlay. This was a totally digital workflow. The patient’s old prosthesis was used to copy the bite relationship, which was then sent to ExoCad software. Here the bite was evaluated similarly to using a semi-adjustable articulator.

The PMMA overlay was then milled according to the treatment plan. The prosthesis was then characterized, including the gums, to ensure a natural esthetic result. The CAD bars had the PMMA cemented so that the metal went all the way down to the gingiva (see image below).

Finished and Tried In

This patient required a restorative option that allowed for the easy repair and upkeep of his prosthesis.

In addition, a PMMA Hybrid from Burbank Dental Lab provides the following benefits:

• PMMA is a resilient material that helps to reduce impact forces, ensuring that it does not get transferred to the implants.
• Easy to repair should the need arise.
• While it can become stained over time, it can be easily polished.
• It will not wear down opposing natural teeth.
• PMMA provides a more cost-effective option.

The case was then finished and tried in. The patient’s bite was evaluated, and he indicated he was comfortable and loved the results.

This case had an amazing result and provided the patient with a great smile and, more importantly, a long-term option to ensure his new prosthesis would address his needs. PMMA provides many benefits, and for this patient, the ability to repair the prosthesis was the main determinant to choosing this restorative option.

Burbank Dental Lab has extensive experience with fixed implant-supported prostheses. Call or chat today with any questions.

Burbank Dental Lab would like to thank Dr. August de Oliveira for allowing us to use his photos for this case and for providing notes for this article.