Cast Metal Posts Research Articles

A method to minimize adjustment and enhance passivity of cast post-and-core restorations

The fitting of cast post-and-core restorations is critical to ensure good adaptation and passivity of fit. 1 Morgano S.M. Brackett S.E. Foundation restorations in fixed prosthodontics: current knowledge and future needs. J Prosthet Dent. 1999; 82: 643-657 Abstract Full Text Full Text PDF PubMed Scopus (144) Google Scholar , 2 Goerig A.C. Mueninghoff L.A. Management of the endodontically treated tooth. Part II: technique. J Prosthet Dent. 1983; 49: 491-497 Abstract Full Text PDF PubMed Scopus (30) Google Scholar , 3 Sorensen J.A. Engelman M.J. Effect of post adaptation on fracture resistance of endodontically treated teeth. J Prosthet Dent. 1990; 64: 419-424 Abstract Full Text PDF PubMed Scopus (135) Google Scholar If a passive fit is not achieved, wedging stresses may result in root fracture. 4 Morgano S.M. Milot P. Clinical success of cast metal posts and cores. J Prosthet Dent. 1993; 70: 11-16 Abstract Full Text PDF PubMed Scopus (115) Google Scholar However, in some situations, cast posts and cores do not fit precisely and, consequently, require adjustment, which may result in looseness of fit. 5 Holmes D.C. Diaz-Arnold A.M. Leary J.M. Influence of post dimension on stress distribution in dentin. J Prosthet Dent. 1996; 75: 140-147 Abstract Full Text PDF PubMed Scopus (184) Google Scholar , 6 Tjan A.H. Whang S.B. Resistance to root fracture of dowel channels with various thicknesses of buccal dentin walls. J Prosthet Dent. 1985; 53: 496-500 Abstract Full Text PDF PubMed Scopus (139) Google Scholar Indicating materials can be used to evaluate the fit of cast posts and cores. However, adjustment using carbide burs is not always exclusive to the binding areas and may result in overadjustment, thus influencing retention. 2 Goerig A.C. Mueninghoff L.A. Management of the endodontically treated tooth. Part II: technique. J Prosthet Dent. 1983; 49: 491-497 Abstract Full Text PDF PubMed Scopus (30) Google Scholar , 4 Morgano S.M. Milot P. Clinical success of cast metal posts and cores. J Prosthet Dent. 1993; 70: 11-16 Abstract Full Text PDF PubMed Scopus (115) Google Scholar

An alternative method for fabricating a custom‐made metal post with a ceramic core

The restoration of anterior non-vital teeth with metal posts and cores and all-ceramic restorations may lead to compromised esthetics because of the semi-translucence of ceramics and the metallic color of the underlying post and cores. This article presents a technique that combines the optical properties of ceramic cores with the mechanical properties of custom-made cast metal posts. The technique involves heat pressing of the core from leucite-enriched glass-ceramic to the underlying custom-made metal post and may provide additional esthetic benefit for anterior teeth especially with little remaining coronal dentin and with small root volume.

Efficacy of ultrasound in removal of intraradicular posts using different techniques

The efficacy of ultrasound in removing cast metal posts was evaluated in this in vitro study using one or two ultrasound units and ultrasonic vibration for various lengths of time. The crowns of 30 healthy maxillary canines were removed, the roots were embedded in acrylic resin blocks, and the root canals were treated endodontically. The canals were prepared and their impressions were taken with self-curing acrylic resin. After casting with copper-aluminum alloy, the posts were blasted with aluminum oxide and cemented with Panavia F resin cement. The specimens were divided into five groups. In groups I and II, only one ultrasound unit was used for 30 and 60 s, respectively; in groups III and IV, two ultrasound units were used simultaneously for 30 and 60 s, respectively; in group V, ultrasound was not used (control). Ultrasonic vibrations were applied with an Enac OE-5 ultrasound unit and an ST-09 tip. All samples were subjected to traction on an Instron machine (model 4444) at a cross-head speed of 1 mm/min. Analysis of the results revealed a statistically significant difference between the groups (ANOVA, P < 0.01); however the difference between groups II and IV was not statistically significant. The efficacy of ultrasound in removing intraradicular posts was confirmed, and the most effective technique was the use of two ultrasound units, independent of the length of time ultrasound was applied.

A SIMPLIFIED PATTERN FOR A CAST METAL POST

A SIMPLIFIED PATTERN FOR A CAST METAL POST

Clinical success of cast metal posts and cores

The topic of posts for endodontically treated teeth has received considerable attention in the literature, but there is sparse in vivo research and certain information from in vitro investigations is contradictory. A retrospective study of 1273 endodontically treated teeth in the practices of nine dentists in general practice indicated an inordinately high failure rate with cast posts and cores compared with alternate systems of coronoradicular stabilization. However, a closer evaluation of the data in this study indicated that almost half of the cast posts were half the desired length or less. The indications for the cast post and core are discussed and the specific causes of failure are reviewed. Additional research is needed to compare the success rate of securely seated cast posts and cores with alternate methods of coronoradicular stabilization.