Swiss dental resin manufacturer Saremco Dental AG has released a new photosensitive polymer resin for 3D printed permanent restorations such as crowns, inlays, inlays and veneers. Prior to its release, CROWNTEC resins were routinely qualified for conformity assessment services and pre-marketing by the global certification company TüVSüD, which is the designated body of the European Union's Medical Device Directive. The resin is also the subject of research at the University of Zurich in Switzerland. The research shows that UV-curable CROWNTEC may be a valuable competitor for traditional ceramic crowns.
The work of the university's dental medical center is to pit the resin and three traditional particle-filled composite ceramics during the breaking load test. These four materials are used to manufacture a total of 180 crown samples with different wall thicknesses (0.5mm, 1mm, 1.5mm) and 3D print the resin on the ASIGA system. The mechanical performance test equipment provided by the university was used to test the thermo-mechanical load and fracture of the crown.
Because it is similar to bone in color and texture, ceramic or porcelain crowns are a popular choice in the dental field. Despite its lower mechanical properties compared to gold or silver, ceramics are still the preferred dental restoration materials worldwide. In order for an experimental light-curing resin to surpass traditional porcelain tooth restorations in general, it must show excellent mechanical properties, resemble bones and be affordable.
So how does Saramco's resin build up? The fracture test of the resin compared with the traditional ceramics varying between 10-15GPa, the Young's modulus of 3D resin is 4.5GPa. Lower Young's modulus means that the material is more elastic and therefore less likely to break under tensile load. Traditional ceramics are more fragile and may break under great pressure. The researchers determined that the average loading force of the 3D resin in the 1.5mm group was 1479N. On the contrary, the average load force of traditional ceramics is 1580N, 1251N and 1516N, which means that the impact force of 3D resin is higher than one of the ceramics without breaking, but not behind the other two. The average loading force of each material increases with increasing wall thickness. It was then determined that the dental resin had related mechanical properties that were about the same as or better than the traditional ceramic crowns found in the dental industry today.
More detailed information on the study can be found under the heading "Fracture load of composite crowns made with CAD / CAM and 3D printed as a function of material thickness." It is co-authored by Zimmerman M., Ender A., Egli G., Ozcan M. and Mehl A. Dental resins must have a certain level of toughness and durability because they are applied once they are in a stable state of use. Last year, SLA 3D printer manufacturer Formlabs announced its Digital Denture resin at a trade show in Las Vegas, which has the qualities necessary for direct 3D printing of dental restorations. Earlier this year, Formlabs also announced a partnership with BEGO, which will enable dental professionals to use BEGO ’s new leading dental materials with Formlabs ’resin printers for temporary and permanent restorations.