Search

Purpose: The Ad Hoc Committee on Research in Fixed Prosthodontics established by the Academy of Fixed Prosthodontics publishes a yearly comprehensive literature review on a selected topic. The subject for this year is foundation restorations., Methods: Literature of various in vitro and in vivo investigations that included technical and clinical articles was reviewed to provide clinical guidelines for the dentist when selecting methods and materials for restoration of structurally compromised teeth. Topics discussed and critically reviewed include: (1) desirable features of foundation restorations, (2) foundations for pulpless teeth, (3) historic perspectives, (4) cast posts and cores, (5) role of the ferrule effect, (6) prefabricated posts, (7) direct cores, (8) foundation restorations for severely compromised teeth, (9) problems and limitations, (10) future needs, and (11) directions for future research., Conclusion: This comprehensive review brings together literature from a variety of in vitro and in vivo studies, along with technique articles and clinical reports to provide meaningful guidelines for the dentist when selecting methods and materials for the restoration of structurally compromised teeth.

The preservation of a severely damaged tooth with a cast restoration requires that the preparation be modified to make use of remaining tooth structure. Preexisting preparation features, such as boxes and isthmuses, and new ones, such as boxes, grooves, and pin holes, are employed to provide adequate retention and resistance. When destruction of coronal tooth structure exceeds one-half of the clinical crown, a pin-retained amalgam or composite resin core should be used to build up the tooth to receive a cast restoration.

This investigation evaluated the flexural strengths of five porcelains commonly used in the all-porcelain margin technique and the effect of surface treatment on the flexural strength. Thirty samples were made by using each of five different porcelain margin systems. The five porcelain groups were subdivided into groups of 10 each to allow the evaluation of three surface treatments. A three-point flexural test was used to test the specimens on a universal testing machine. Crystar shoulder porcelain with distilled water as the binder was significantly stronger than the other porcelains tested, and porcelain treated with an overglaze was stronger than porcelain treated with autoglaze or autoglaze and polish.