Heat-pressing Technique for a Novel Fluorapatite Glass Ceramics

Abstract

Fluorapatite glass-ceramics are commonly used in dentistry for their combination of mechanical strength and aesthetic appeal. However, commercially available options, such as IPS e.max Zirpress present limitations, including excessive abrasiveness to natural dentition and potential for fracture. These ceramics can be manufactured using CAD/CAM milling, powder–liquid layering, or heat-pressing techniques.

The heat-pressing method, in particular, offers enhanced control over crystal growth and microstructure, potentially improving both strength and translucency. In this study, we fabricated a novel fluorapatite glass-ceramic using heat-pressing and compared it to IPS e.max Zirpress, as well as to CAD/CAM and powder–liquid forms of the same novel material. Mechanical and aesthetic performance were evaluated through hardness testing, fracture toughness, biaxial flexural strength (BFS), scanning electron microscopy (SEM), and translucency measurements. The novel heat-pressed material showed lower hardness than IPS e.max Zirpress, indicating reduced abrasiveness, while exhibiting higher hardness than its CAD/CAM and powder–liquid counterparts. It also demonstrated improved crack resistance and higher BFS compared to IPS e.max Zirpress. However, its mechanical performance remained slightly lower than the other two fabrication forms.

Although the heat-pressed version did not outperform CAD/CAM or powder–liquid samples in all aspects, it addressed key drawbacks of IPS e.max Zirpress, offering reduced wear to opposing teeth, enhanced fracture resistance, and comparable translucency. These findings suggest it could serve as a promising alternative for dental restorations, especially where a balance of strength and aesthetics is required.