Types of Dental bridges
There are two mainstream types of fixed (meaning non-removeable) dental bridges:
When dental implants cannot be employed to replace a missing or extracted tooth, then a fixed or permanently cemented dental bridge is the next best solution. These non-removeable tooth replacements can be constructed out of many materials. The design and overall strength of these restorations is evolving quickly. At this time, the most common porcelain varieties (e.g. Zirconium, Procera, E Max) used as substructures or frameworks still have lower flexural strength relative to metallic versions but their popularity is growning rapidly. The restorative dentist and patient must weigh the risk of occlusal forces and abuse against the ease of creating an esthetic result.
Porcelain supported by a metal substructure (PFM) Bridge
When the supporting substructure is placed under unusually heavy loads, veneering porcelain can chip or fracture off of any bridge or crown. Porcelain is like glass; it has a low tensile strength. If there is significant flexure, it will crack, chip, or break. Adding a metallic substructure under the porcelain will reduce flexing under trauma or excessive loads. If the patient is hard on their dentition with clenching or grinding, it is advisable to support the superficial veneering layer of ceramic with some sort of metal substructure. There are many types of metallic substructures which can be added when maximum strength is needed.