Fixed prosthodontics deals with crowns and bridges on natural teeth or implants. In general, a tooth needs a crown when it has undergone root canal treatment (to protect it from fracture), when it has lost a significant amount of tooth structure due to decay or fracture, and when it serves as an abutment for a partial denture.
A bridge is constructed when one or more teeth are missing from the dental arch and their replacement with implants has been excluded.
Crowns may be metal-ceramic or fully ceramic, while bridges are typically constructed with a metallic framework for strength during chewing, which is then fully veneered with porcelain for aesthetic purposes.
In areas of the mouth with high aesthetic demands, zirconia or lithium disilicate (IPS e.max) frameworks are preferred, to avoid the unsightly grey line at the gum margin sometimes seen in metal-ceramic restorations.
In all cases, provisional acrylic crowns are fabricated during treatment to meet the patient's functional and aesthetic needs until the final restoration is cemented.
Removable prosthodontics deals with the construction of partial or full dentures in cases where the remaining natural teeth are not sufficient to support fixed restorations. They also offer a solution when, for various reasons, implants cannot be placed or an adequate number of implants cannot be placed to support fixed bridges.