Fixed prosthodontics deals with crowns and bridges on natural teeth or implants. In general, a tooth needs a crown when it has been subjected to root canal treatment in order to be protected from fractures when it has lost a large quantity of healthy dental matter due to decay or fracture and when it is used as support of a partial denture.
The construction of a bridge is essential when one or more teeth are missing from the dentition and their replacement with implants has been excluded.
The crowns may be metal-ceramic or fully ceramic, while they are usually manufactured with a metallic frame for endurance during chewing which, in turn, is totally covered with porcelain for aesthetic reasons.
In areas of the mouth with high demands in aesthetics, there is preference in frames made of zirconia or lithium disilicate (IPS e.max) in order to avoid the unsightly grey zone at the area of the free gums, which is observed in metal-ceramic restorations due to the metallic frame.
In any case, during the treatment, temporary acrylic crowns are built so as to cover the functional and aesthetic needs of the patient until the cementation of the final work.
The branch of Removable Prosthodontics deals with construction of partial or full dentures in cases where the remaining natural teeth are not sufficient to support fixed prosthodontics. Furthermore, they constitute a solution when, for various reasons, implants cannot be placed or a satisfactory number of implants cannot be set to sustain bridges.