RESUMO
Objetivos: Medir la resistencia a la fractura en premolares tratados endodónticamente, restaurados con dos sistemas de pernos (Colados/ Prefabricados) y analizar el patrón de fractura que se produce en la raíces. Materiales y Métodos: a 60 premolares humanos monorradiculares se les realizó la terapia endodóntica. Se dividió la muestra aleatoriamente en dos grupos (30 c/u), el grupo 1 (G1FV) se restauró con pernos prefabricados de Fibra de Vidrio (Ángelus®) y el grupo 2 (G2C) con pernos colados de aleación base (Orca Plus /Ventura), utilizando cemento resinoso Nexus 2 (Kerr), los 2/3 coronales de ambos grupos fueron restaurados con resina compuesta híbrida (Glacier A1/ SDI). Las muestras fueron cargadas a una velocidad de 2mm/min y a una angulación de 30° con el eje longitudinal del diente en la máquina de prueba universal (Shimadzu AGS- J), la resistencia a la fractura fue medida en newtons y analizada con ANOVA de una vía; por medio de la observación directa y Rx se determinó el patrón de fractura que fue analizado con X² y Prueba Z. Resultados: En relación a resistencia a la fractura no hubo diferencia estadísticamente significativa entre los grupos (p=0,741). En cuanto al patrón de fractura se observó diferencia estadísticamente significativa entre los grupos estudiados (Zc=4,47). Conclusiones: En las condiciones en las que se realizó esta investigación se observó que los dos sistemas de perno y núcleo resisten de manera similar a las tensiones inducidas. En cuanto al patrón de fractura radicular en el G1FV se producen menor número de fracturas no reparables cuando se compararon con el G2C.
Objective: The purpose of this research was to compare the fracture resistance of human premolars restored with prefabricated fiber glass posts and custom cast post and to analyze the nature of the root fracture patterns. Methods: 60 human monoradicular premolars were prepared with endodontic therapy and randomly assigned to one of two groups: group 1 (G1FV) recovered with prefabricated fiber glass posts (Ángelus) or group 2 (G2C) with custom cast base alloy posts (Orca /Ventura Extra) using resinous luting cement (Nexus2/Kerr). 2/3 of the crowns were restored with hybrid composite (Glacier A1/SDI). The samples were loaded at a speed of 2mm/min and to a 30° angulation with the longitudinal axis of the tooth in the universal testing machine (Shimadzu AGS- J).The fracture resistance was recorded and analyzed with one way ANOVA. The nature of the root fracture patterns was determined through direct observation and Rx; these data were analyzed with X² and Z test.Results: After the ANOVA analysis no statistically significant differences were observed in relation to fracture resistance between groups (p = 0,741). However, significant differences were found for the nature of the root fracture between the groups (Zc=4, 47). Conclusions: Under the conditions of this study, both systems of posts have a similar fracture resistance. In relation to root fracture patterns, there are less catastrophic fractures in the G1FV when compared to G2C.
RESUMO
In the restoration of endodontically treated teeth, carbon fiber post was recently introduced. The purpose of this in vitro study was to investigate the fracture strength of teeth restored with a preFabricated carbon fiber post in comparison with teeth restored with a prefabricated titanium post & custom cast gold post after cyclic loading in the different environment. A total of 30 recently extracted human central incisors of similar dimension with crowns removed were used. All teeth were placed into acrylic blocks and every steps for post and core fabrication were made according to manufacture s instruction. The post length and core dimensions were standardizd. All teeth were divided into 6 groups 1) carbon fiber post / atmosphere, 2) titanium post / atmosphere, 3) gold post / atmosphere, 4) carbon fiber post / wet, 5) titanium post / wet, 6) gold post / wet. Carbon fiber post and titanium post were cemented in place using resin cementt and cores were fabricated with Ti-Core. Custom cast gold post was made from Dur clay pattern resin and cemented using resin cement, too. All specimens were thermocycled 10,000 times. After 50,000 cyclic loading, failure strength was measured using Instron testing machine. KruskalWallis test followed by Mann-Whitney test was used to compare the mean fracture strength. Results were as follows 1. All specimens showed lower fracture strength in wet environment after cyclic loading than in atmosphere condition, but did not reveal a significant difference. 2. There was no significant difference between carbon fiber post specimen and titanium post spec imen in the same environment. 3. Gold cast post specimen showed significant different greater fracture strength than those of others in the same environment. 4. Carbon fiber post specimen showed no root fracture.