Source: TCT Asia Perspective
Due to its excellent biocompatibility, ceramic materials are recommended as the first choice materials, from dental restorations, implants to bone graft materials. Unlike metals, ceramic materials have no ion release or corrosion problems, and have long-term stability in both soft and hard tissues. In addition, ceramic materials also show significant advantages when making restorations, which can make the restoration look as natural as possible for a long time. From an aesthetic point of view, the effect of all-ceramic restoration materials on optically imitating natural teeth has obvious advantages over metals; in the case of gingival recession, gray shadows will not appear in the gum area and implants.
Zirconium oxide is often called “ceramic steel”. In the field of restorative dentistry, zirconia is often used to repair missing teeth or tooth substances, supporting crowns through teeth, fixed dental restorations (FDP) and defective restorations (Such as occlusal veneer) to repair. Zirconium oxide can also replace missing teeth with dental implants and implant support restorations.
At present, the CAM (Computer Aided Manufacturing) program for processing zirconia is processed by subtraction technology, that is to say, the aforementioned zirconia parts are made of prefabricated zirconia blanks in a pre-sintered state, the so-called white body state Processed. In this state, the inherent strength of zirconia is low. Due to this fact, the thin frame may break during the subtraction process, resulting in a significant difference between the designed and manufactured parts.
For this reason, thin bezels and edges must usually be over-contoured in these areas to prevent edge breakage during processing. However, this also leads to a lot of post-processing work in these areas. Since the crown edge and the occlusal surface are a very important area of the crown and bridge restoration, the post-processing must be performed under a stereo microscope. This post-processing is quite time-consuming and costly. In addition, the fissures of the occlusal surface also need to be post-treated, because rotating instruments can only reproduce the classic tapered fissure geometry to a limited extent.
With the continuous improvement of aesthetics and performance requirements, ceramic 3D printing emerged as a solution to meet the challenges of the dental field. It provides new design freedom, enabling complex 3D metal-free applications to be produced layer by layer, while overcoming the technical limitations of standard ceramic processes.
Using 3D printing technology, there is no limit to the location of the milling blast and the thickness of the repair. Minimally invasive veneers can reliably produce minimally invasive veneers with very thin borders, with feathering edges as low as 100 μm. Compared with milled veneers, it has better mechanical stability. In addition, since 3D printing can produce geometric shapes similar to the nature of the occlusal surface, the aesthetic effect of single-piece repair can be achieved.
For replacing missing teeth, endoscopic screw-type implants are a suitable treatment method. Using lithographic ceramic manufacturing technology, mass-produced ceramic implants with complex shapes and targeted to patients can be mass-produced with a high degree of repeatability. In such a production environment, the annual output of the machine can reach more than 60,000 pieces.
In addition, ceramic 3D printing technology provides different applications in craniofacial surgery and the treatment of severe mandibular bone defects. When treating such a large defect, the challenge is that if proper measures are not taken, the bone itself cannot heal the defect. Therefore, a two-pronged approach is proposed here. The high-strength zirconia shell provides proper support during the healing phase, and the internal volume of the implant is made of bioabsorbable β-calcium phosphate (β-TCP). Practice has proved that ß-TCP has good osseointegration properties. By selecting the appropriate pore size and bearing size, it can significantly affect the growth of bones. ß-TCP is reabsorbed by cells and replaced by newly formed bone, and the zirconia cage can be kept in place due to its good biocompatibility.