In their article "High-performance polymers - part two" published in Private Dentistry (Nov. 2015), Professor Paul Tipton (Follow on Twitter) and Dr Bernd Siewert (Follow on Wordpress) continue their review of high-performance polymers (HPP) in dentistry, with the focus on polyetheretherketone (PEEK). In this post you can follow some of the highlights of this article focusing on an experiential comparison between injection-moulding and CAD/CAM milling in the fabrication of dental prosthetics, and the advantages of CAD/CAM milling - in the context of the JUVORA dental disc.
The CAD/CAM advantage
PEEK-OPTIMATM, the high-performance polymer has been established in many areas of medicine, over a number of years, and is gaining an increasing number of advocates in dentistry, thanks to its thanks to its superior biomechanical performance1,2. In particular, the CAD/CAM processing of PEEK-OPTIMA opens up new options. Dental blank discs, with approval for permanent restorations, have recently become available in the form of the JUVORA dental disc, made from PEEK-OPTIMA. This is a biomaterial, containing no additives3, that has been in use in the medical industry for many years.
What's more, the JUVORA dental disc is not adversely affected during the fabrication process, provided it is used correctly. CAD/CAM fabricated bridge frameworks milled from this high-grade blank undergo no physical changes during the fabrication process, and as the two scientists claim, they exhibit excellent material-technical properties.
Crucially, CAD/CAM-based milling results in:
- High-quality bridge frameworks with no material faults
- Precise manufacture
- Reduced manufacturing time4
- An easily reproducible fabrication process
JUVORA in clinical practice
One particular case that arose in clinical practice was a 55-year-old female patient referred for implant treatment and prosthetic restoration. She had previously been treated via a bar-supported denture, placed on four implants.
The decision was made to proceed with CAD/CAM-supported fabrication of a fully anatomical bridge framework, to achieve the prosthetic restoration. The chosen solution was the JUVORA dental disc, which enables the fabrication of highly precise restorations.
To ensure that the bridge fitted passively, the four implant copings in the mouth were adhesively retained, and the new restoration was then fitted. The non-veneered JUVORA bridge framework was barely noticeable as an occlusal surface material.
PEEK-OPTIMA - tried and tested
PEEK-OPTIMA polymer, from Invibio, has been tried and tested as a biomaterial in the medical field for over 15 years, and its high biocompatibility has been proven in several clinical studies5. The low specific weight, its toughness combined with a bone-like elasticity, and fatigue resistance make it an ideal material for use in prosthodontics.
The CAD/CAM-supported processing of the non-metallic PEEK-OPTIMA opens up new possibilities, especially since the physical properties of the material allow approximately the same design dimensions as those of metallic materials. To date, approval of the JUVORA dental disc covers:
- removable restorations,
- implant-borne prosthetics,
- crowns and bridges.
This means that denture bases, secondary units, prosthetic superstructures with fixed or removable restorations, implant-supported posterior full crowns, and operator-removable, screw-retained bridges can now be fabricated using the JUVORA dental disc.
The CAD/CAM breakthrough
The positive clinical experience of using fully anatomical JUVORA bridge frameworks fabricated with an injection-moulding technique can now be obtained by CAD/CAM processing. This allows frameworks to be fabricated with a reliable, highly precise and reproducible production procedure.
More details in the High-performance Polymers - Part Two article published in Private Dentistry (Nov. 2015).
1 Industry testing in-mouth simulation measured JUVORATM at 1,300N force.
2 The JUVORATM Dental Disc is made using PEEK, which requires less force to bend, and it can be repeatedly bent without breaking, unlike other stronger materials.
3 Kurtz, S (2012). “PEEK Biomaterials Handbook”. Edition 1, Oxford, Elsevier Inc.
4 Independent laboratory based test demonstrated milling JUVORATM implant prosthetic framework in one hour, 21 minutes, versus Titanium equivalent in three hours, 50 minutes.
5 Rho, JY et al (1993). “Young’s modulus of trabecular and cortical bone material: Ultrasonic and microtensile measurements”. Journal of Biomechanics 26 (2); 111–119. Other clinical studies available on request.