Fatigue Behavior of Different CAD/CAM Materials for Monolithic, Implant-Supported Molar Crowns.

Autor: Sotto-Maior BS; Department of Restorative Dentistry, Federal University of Juiz de Fora, Juiz de Fora, Minas Gerais, Brazil., Carneiro RC; Department of Implantology, São Leopoldo Mandic Institute and Research Center, Campinas, São Paulo, Brazil., Francischone CE; Department of Implantology, São Leopoldo Mandic Institute and Research Center, Campinas, São Paulo, Brazil., Assis NMSP; Department of Clinical Dentistry, Federal University of Juiz de Fora, Juiz de Fora, Minas Gerais, Brazil., Devito KL; Department of Clinical Dentistry, Federal University of Juiz de Fora, Juiz de Fora, Minas Gerais, Brazil., Senna PM; Health Science Center, Unigranrio University, Duque de Caxias, Rio de Janeiro, Brazil.
Jazyk: angličtina
Zdroj: Journal of prosthodontics : official journal of the American College of Prosthodontists [J Prosthodont] 2019 Feb; Vol. 28 (2), pp. e548-e551. Date of Electronic Publication: 2018 Jun 13.
DOI: 10.1111/jopr.12922
Abstrakt: Purpose: To evaluate the fracture resistance after the thermal and mechanical fatigue of feldspathic, lithium disilicate, and resin-modified CAD/CAM monolithic crowns cemented onto a universal post abutment.
Materials and Methods: A right second mandibular molar was designed in CAD/CAM software, and 30 crowns were machined using three different materials (n = 10): feldspathic ceramic, finished only with a glaze cycle (G1); lithium disilicate, sintered and finished with a glaze cycle (G2); and resin, modified by nanoceramic and finished with rubber (G3). All crowns were cemented under a constant 50 N load, the excess cement was removed, and the crowns were light-cured for 30 seconds. After being immersed in deionized water for 7 days, the crowns were submitted to thermal cycling, which consisted of varying the temperature from 2 to 50°C for 350,000 cycles, and mechanical cycling in a fatigue simulator, where a 250 N load was applied for 1,000,000 cycles at 2 Hz. The resistance of each crown was verified in a compression-to-failure test at 1 mm/min in a universal test machine. The groups were compared using one-way ANOVA with a Bonferroni post hoc test and Weibull statistics.
Results: The resin-modified group was the least resistant group (1755 ± 124 N), followed by the feldspathic (2147 ± 412 N) and lithium disilicate groups (2804 ± 303 N). The Weibull statistics demonstrated that lithium disilicate is the most reliable material and has the lowest fracture probability.
Conclusions: It was possible to conclude that all of the tested CAD/CAM materials can be used as monolithic, implant-supported molar crowns.
(© 2018 by the American College of Prosthodontists.)
Databáze: MEDLINE
Externí odkaz: