The Journal of prosthetic dentistry · 2010
Evaluation of a one-piece milled zirconia post and core with different post-and-core systems: An in vitro study.
Сравнительное исследованиеОценочное исследованиеСтатьяПоддержка исследования: вне правительства СШАНазвание и аннотация: Перевод в очереди
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Bittner Nurit, Hill Thomas, Randi Anthony
Аннотация
STATEMENT OF PROBLEM: One-piece milled zirconia posts and cores present an esthetic option as foundation restorations for ceramic crowns. To date, dimensional fit and load capacity of 1-piece zirconia posts and cores have not been determined.
PURPOSE: The purpose of this study was to evaluate the accuracy of fit of milled zirconia posts and cores and to compare the shear strength with other post-and-core systems.
MATERIAL AND METHODS: Eighty-five maxillary central incisors and canines received endodontic treatment and were divided into 5 groups (n=17) as follows: cast gold post and core (Au) as control, 1-piece milled zirconia post and core (Zr), prefabricated zirconia post with heat-pressed ceramic core (Zr/Cer), titanium post and composite resin core (Ti), and combined fiber/zirconia post with composite resin core (Fiber/Zr). The posts and cores were cemented with dual-polymerized composite resin cement (Multilink). Zirconia copings were made for each specimen, cemented, and loaded to failure. Fracture loads and modes of failure were recorded. Fracture loads were compared with a linear model. Differences in the mean marginal gap distance between the post-and-core patterns and the adjusted milled zirconia posts and cores were analyzed with a paired t test (alpha=.05).
RESULTS: A significant difference was found in the marginal gap distance of group Zr (P<.001), compared with the marginal gap distance of the acrylic resin patterns. Mean loads to failure were highest for the Fiber/Zr group in comparison with custom-made milled zirconia posts and cores (P<.001).
CONCLUSIONS: All systems evaluated presented sufficient mean load-to-failure values for anterior tooth restorations, including the recently developed 1-piece milled zirconia post and core.
PURPOSE: The purpose of this study was to evaluate the accuracy of fit of milled zirconia posts and cores and to compare the shear strength with other post-and-core systems.
MATERIAL AND METHODS: Eighty-five maxillary central incisors and canines received endodontic treatment and were divided into 5 groups (n=17) as follows: cast gold post and core (Au) as control, 1-piece milled zirconia post and core (Zr), prefabricated zirconia post with heat-pressed ceramic core (Zr/Cer), titanium post and composite resin core (Ti), and combined fiber/zirconia post with composite resin core (Fiber/Zr). The posts and cores were cemented with dual-polymerized composite resin cement (Multilink). Zirconia copings were made for each specimen, cemented, and loaded to failure. Fracture loads and modes of failure were recorded. Fracture loads were compared with a linear model. Differences in the mean marginal gap distance between the post-and-core patterns and the adjusted milled zirconia posts and cores were analyzed with a paired t test (alpha=.05).
RESULTS: A significant difference was found in the marginal gap distance of group Zr (P<.001), compared with the marginal gap distance of the acrylic resin patterns. Mean loads to failure were highest for the Fiber/Zr group in comparison with custom-made milled zirconia posts and cores (P<.001).
CONCLUSIONS: All systems evaluated presented sufficient mean load-to-failure values for anterior tooth restorations, including the recently developed 1-piece milled zirconia post and core.