The maximum amount of unsupported porcelain recommended for dental restorations is 2 mm. This guideline is based on considerations of strength and durability. In dental restorations, porcelain is a brittle material, and increasing the thickness of unsupported porcelain can significantly elevate the risk of fracture.
When utilizing porcelain for crowns or veneers, it is essential to maintain a balance between aesthetics and mechanical properties. At 2 mm, the unsupported porcelain has enough material to provide good aesthetics while minimizing the risk of breakage and ensuring that the restoration remains functional over time.
Thicker layers might compromise the integrity of the restoration, as stress distribution becomes uneven, making the material more susceptible to chipping or breaking, especially in areas subject to significant occlusal forces. Therefore, adhering to the recommendation of 2 mm helps optimize the longevity and reliability of dental restorations made with porcelain.