Fiberglass versus cast metal posts: a practical review based on mechanical properties

Abstract

The current review aimed to compare the mechanical properties and clinical behavior of fiberglass and cast metal posts. It included in-vitro studies, finite element analysis, clinical studies, and systematic reviews that evaluated fiberglass and metal posts with reliable methodologies. The reports in the literature diverge on tooth failure modes and stress distributions in the root according to different posts. Investigations suggest that fiberglass posts are preferable because their elastic modulus is similar to dentin. Other studies mention that the flexibility of fiber posts may damage the interface. The fracture load values of different studies could not be compared. The presence of a ferrule seems beneficial. Cast metal posts provide higher characteristic strength to the set but with more unfavorable failures. Intraradicular posts with a lower elastic modulus produce more stress between the cement layer and dentin. In conclusion, fiberglass and cast metal posts can be used with a ferrule. Cast metal posts seem more appropriate for weakened teeth. The presence of a ferrule benefits the system. Weakened teeth tolerate higher loads when restored with cast metal posts, but when these posts fail, the only solution is tooth extraction. Clinical follow-ups cannot yet detect differences between the survival rates of intraradicular fiberglass and cast metal posts.

The Use of Polyetheretherketone (PEEK) as an Alternative Post and Core Material: Five-Year Follow-Up Report

“…In the contemporary dental literature, a variety of materials have been tested as post and core systems to reduce the catastrophic fracture of the remaining tooth structure, particularly those with close biomechanical behaviors to dentin [ 4 , 6 , 10 ]. In addition, it was reported that CAD/CAM technology provides homogeneous and standard blocks of materials manufactured for an industrially regulated milling operation [ 1 , 2 , 3 ].…”

“…In cases of extensive coronal tooth destruction, where extra retention is required, a post should be inserted to the root in order to retain the core and the restoration [ 4 , 5 , 6 ] The choice between using a custom-made post or a prefabricated one relies on multiple factors, such as canal configuration, remaining tooth structure and restorative technique [ 7 , 8 , 9 ] The custom-made posts are fabricated mainly from metal, zirconia, and fiber-reinforced composite [ 10 , 11 , 12 , 13 , 14 ].…”

“…According to the literature, the optimal material for manufacturing post and core should have an elastic modulus that accommodates the normal flexural dynamics of the root [ 4 , 6 , 10 ]. Post and core materials with dentin-like biomechanical properties could also be beneficial in minimizing the risk of root fractures or debonding [ 20 , 21 ].…”

Biomimetics and the restoration of the endodontically treated tooth

“…Another important aspect to be considered when restoring the endodontically treated tooth is the presence of a ferrule (Figure 1). The called "ferrule effect" can be defined as a circumferential dentin collar of 2 mm or more in height [29,30,31]. Overall, a ferrule represents a determining factor in the strain, fracture resistance, and fracture pattern [30] that will increase tooth strength due to the remaining coronal dentin, and untimely, improve the longterm prognosis [24,32].…”

Three-Dimensional Finite Element Study of Endodontically Treated Maxillary Central Incisors Restored Using Different Post and Crown Materials

“…They can withstand high occlusal forces before deformation occurs because of their high modulus of elasticity [ 11 , 12 ]. However, some studies reported that cast posts may cause root fractures because of their rigidity [ 13 ]. In addition, the prevalence of highly translucent ceramic crowns raises a concern regarding their esthetic proprieties.…”