Influence of the remaining coronal structure on the resistance of teeth with intraradicular retainer

Abstract

The aim of this study was to compare the resistance of endodontically treated teeth with intraradicular retainer different amounts of remaining coronal structure. Fifty freshly extracted maxillary canines were endodontically treated and randomly assigned to five groups (n=10), as follows: group 1 (control) = teeth with custom cast post and core; group 2 = teeth without remaining coronal structure; group 3, 4 and 5 = teeth with 1 mm, 2 mm and 3 mm of remaining coronal structure, respectively. All specimens in groups 2 to 5 were restored with prefabricated post and resin core. The teeth were embedded in acrylic resin and the fracture strength was measured on a universal testing machine at 45 degrees to the long axis of the tooth until failure. Data were analyzed statistically by one-way analysis of variance and Tukey's test. There was no significant differences (p>0.05) between the control group and group 2, and between groups 3, 4 and 5 (p>0.05). Control group and group 2 had significantly higher resistance strength than groups 3, 4 and 5 (p<0.00001). The findings of this study showed that teeth without remaining coronal structure had significantly higher fracture strength than those with remaining coronal structure (1 mm, 2 mm and 3 mm). When the dental crown was not completely removed, the amount of remaining coronal dentin did not significantly affect the fracture strength of endodontically treated teeth with intraradicular retainer.

Ultrasound Effect in the Removal of Intraradicular Posts Cemented with Different Materials

“…17 Rely-X is dual-cure glass ionomer cement, self-adhesive and has been compared with different cements. [18][19][20] Enforce is resin cement presenting dual-setting time that have been studied and evaluated. 21,22 So, when the post-traction is needed, the cement adhesive properties should be considered, 18 since it can lead to more or less difficulty in the post removal.…”

Efeito do pino intra-radicular e da presença de férula na resistência de dentes tratados endodonticamente

“…Alguns estudos (BRAVIN, 1976;STANDLEE, 1976;SIRIMAI;RIIS;RAY JUNIOR, 1992) têm demonstrado que a colocação de um pino intra-radicular pode gerar um maior estresse durante a função, levando, assim, à fratura radicular, outros (AKKAYAN et al, 2002;ASSIF et al, 1993;BARKHORDAR;RADKE;ABBASI, 1989;GEGAUFF, 2000;HOAG;DWYER, 1982;PEREIRA, 2003;PEREIRA et al, 2005;PEREIRA et al, 2006;PIERRISNARD et al, 2002;RICKETTS;TAIT;HIGGINS, 2005;ZHI-YUE;YU-XING, 2003) mostram que a resistência de dentes tratados endodonticamente está diretamente relacionada à quantidade de remanescente dentário presente. Dessa forma, quando não existe remanescente dentário coronal suficiente, os pinos intra-radiculares devem ser indicados para suportar uma coroa (ASSIF et al, 1989;COHEN et al, 1996;GELFAND;GOLDMAN;SUNDERMAN, 1984;GUZY;NICHOLLS, 1979;RAY JUNIOR, 1992).…”

“…(GEGAUFF, 2000;PEREIRA, 2003;PEREIRA et al, 2005;PEREIRA et al, 2006;ROSEN, 1961). O termo férula é derivada da palavra "ferum", do latim, que significa aço e "viriola" que significa pulseira.…”

“…A efetividade da férula tem sido avaliada por uma série de métodos, incluindo teste de fratura (GEGAUFF, 2000;PEREIRA, 2003;PEREIRA et al, 2005;PEREIRA et al, 2006;), teste de impacto (CATHRO;CHANDLER;HOOD, 1996), teste de fadiga (ISIDOR; BRONDUM; RAVNHOLT, 1999) e análise fotoelástica (LONEY; KOTOWICS; McDOWELL, 1990). Vários autores (SORENSEN; ABOU-RASS, 1978;WALDNILD;MUELLER, 2001) têm sugerido que um dente deveria ter uma quantidade mínima de 2mm de estrutura coronal acima da junção cemente-esmalte para garantir uma forma de resistência adequada para o dente.…”

“…Vários autores (SORENSEN; ABOU-RASS, 1978;WALDNILD;MUELLER, 2001) têm sugerido que um dente deveria ter uma quantidade mínima de 2mm de estrutura coronal acima da junção cemente-esmalte para garantir uma forma de resistência adequada para o dente. Essa estrutura coronal providenciará um efeito férula com a coroa artificial que deverá prevenir a fratura da raiz, fratura e deslocamento do pino (AKKAYAN et al, 2002;ASSIF et al, 1993;BARKHORDAR;RADKE;ABBAS, 1989;GEGAUFF, 2000;HOAG;DWYER, 1982;PEREIRA et al, 2006;PEREIRA et al, 2005;PEREIRA, 2003;PIERRISNARD et al, 2002;RICKETTS;TAIT;HIGGINS, 2005;ZHI-YUE;YU-XING, 2003).…”