Manufacturing process of a splint made of PMMA

In today’s dental technology, technical advances and innovations can no longer be dispensed with. As the demands for productivity and precision become more and more important in this dynamic market, flexible and efficient system solutions that nevertheless result in low production costs are increasingly in demand. Subtractive manufacturing processes are the solution to this tension and have thus set a new revolution in motion.

Splint
Picture of a digital finished splint

Not only in the dental industry but also in milling centers, commercial laboratories, and even directly in the dental practice, these are now increasingly part of the standard range. Teeth grinding and clenching is a widespread global problem. More and more patients suffer from it. Increasing stress is considered to be a major cause for the mostly nocturnal and unconscious grinding and clenching of the teeth. A grinding or bite splint can help those affected.

As a laboratory owner, you can produce splints profitably and reliably. Use digital processes for this. In the following text, the digital production of a splint is described in detail. The variety of materials for this indication and the resulting advantages are also discussed in more detail in the following text.

Impression taking/scanning
The process chain always starts with the digital data acquisition of the clinical situation. Digital impressions of human dentition are also becoming increasingly
relevant in CAD/CAM technology. Due to the steadily growing use of intraoral scanners in dentistry, conventional impressions of the teeth are being pushed into
the background and replaced by a digitalised process, a so-called optical impression. Alternatively, the data acquisition of the clinical situation can also be carried out by optical measuring methods (scanners). Optical scanners work completely contact-free with the help of sensors. Therefore, steep surface shapes or preparation boundaries can be recorded without restrictions. After the human dentition has been digitally recorded, the splint is designed using
CAD software.

exocasd
Exocad – Software

Designing CAD
After scanning, the three-dimensional data of the patient are imported into the CAD dental software to design a splint, as in this case. The CAD software used here was exocad. Even the standard version of the software covers a large number of possible indications. The strength of exocad DentalCAD lies in its simple and intuitive handling. The software reflects the analog work processes of a dental technician, which is why even newcomers who are using the software for the first time can easily find their way around. The splint thickness can be determined digitally and has a uniform thickness after milling. This is not possible in the traditional manufacturing process.

CAM

Millbox proces
Millbox – Software

After the splint has been exported from the CAD software, the next step is nesting, i.e. positioning the splint in the workpiece. Millbox – the CAM software from the company CIMsystem which can be recognised by its attractive, easy-to-understand and customised user interface, realises an extremely user-friendly handling. After the correct material has been selected (PMMA blank) and the splint has then been positioned and pinned, the calculation of the
milling data starts. These are then sent on to the milling machine.

Milling DWX-52DCi: Product page

For our case, we used the DWX-52DCi milling machine from DGSHAPE The ultimate in ease, material flexibility, and unattended production.

DWX Series
Left: DWX-52DCI. Right: DWX-52D

DWX-52DCi: With new DWINDEX 2 performance monitoring software, a 6-slot Automatic Disc Changer, 15-station Automatic Tool Changer, and other automated features, it gives users of all skill levels an exceptionally powerful, efficient, and affordable dental restoration solution. In order to meet operator requirements, the development process of the DWX-52DCI systems focused on user-friendly applicability of the milling machine as well as comprehensible and easy-to-use software. The reduced need for user interaction optimizes the workflow for the result of precisely milled objects.

Material

Splint
Thermomemory Effekt

 

Polymethyl methacrylate (PMMA for short) is also called acrylic glass or more often colloquially Plexiglas. Due to its high transparency, this material is very popular for splint fabrication.

Apart from transparent PMMA, the flood of new CAD/CAM-capable materials makes it possible to manufacture splints optimally adapted to the individual needs of the patient, not only with regard to the aesthetic demands but also with a highly precise adaptation to the dental situation.

Digital technology also makes it possible to realize extravagant patient wishes in terms of color variety. for optimal tension-free wearing comfort that are characterized by thermoplastic flexibility with a thermomemory effect.

The industrial polymerisation process achieves the highest material homogeneity and thus guarantees excellent long-term stability. The use of CAD/CAM technology also ensures a safe process, as mixing errors (e.g. due to hand mixing) are eliminated. The special material properties result in a highly precise adaptation to the tooth situation and exceptional, tension-free wearing comfort for the patient.

PMMA temporaries made
Left: Temporaries made of Multylayer PMMA Right: PMMA transparent splints

Allergy sufferers who cannot tolerate PMMA are also in good hands with digital technology and can be provided with alternative materials such as polyamide. Polyamide is also transparent, has very high biocompatibility, is flexible, and very fracture-resistant. PMMA is versatile and is not only suitable for splint fabrication but also, for example, for the fabrication of single crowns and multi-unit bridges up to partial crowns and temporaries in the anterior and posterior region. But PMMA can also be used for many other dental indications. The field of application is wide-ranging in digital production.

 

 

Final review

Final Splint patient
Finished splint in the patient’s mouth

As can be seen in the picture above, the patient is pleased with the smooth process that digital technology has made possible for her. Not only the high wearing comfort has convinced her, but also the fast production.

So, in conclusion, digital dentistry ensures faster treatments, fewer appointments, and reduced manufacturing costs for better clinical results.

 

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