Retenção em canais amplos de núcleos confeccionados por diferentes técnicas com pinos fibro resinosos

• Autor(a) principal: Heimlich, Marcelo Nunes
• Data de Publicação: 2011
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/13978
• topic: Retention; Fiber posts; Root canal; Retenção; Pinos fibro resinosos; Canal radicular; Dentística operatória; Canal radicular - Tratamento; Pinos dentários; Técnica para retentor intra-radicular; CNPQ::CIENCIAS DA SAUDE::ODONTOLOGIA

The aim of this study was to evaluate the retention of fiber posts cemented in enlarged root canals simulating compromised roots, fabricated with to two techniques used to minimize your desadptation; comparing it to posts fixed only with ciment. Twenty four single root human teeth standardized in 15.0mm length and 5.0 ± 0.3mm diameter were used. The roots were imbibed in acrylic resin and divided in groups according to the technique used: group I - DC White Post no2 cemented with quimically cured adhesive system and a dual cured resin cement; group II the same post customized with composite resin to copy the root canal anatomy, cemented the same way; and group III the same post associated with three accessory posts, cemented the same way. The root canals had their diameter standardized using a no2 DC post burs 12.0 mm deep and enlarged with a chamfer bur 10.0 mm deep. The eight roots of each group were transversely sectioned in three 3.0 mm diameter discs, starting from cervical to make the push out test, discarding the last 2.0mm used only to centralize the post. The retention values were registered and statistically treated with ANOVA and SNK tests (p<0.05). Significant differences were observed when comparing the three root portions of all groups investigated, with retention values decreasing from cervical to apical. The retention in apical portion of customized posts was statistically greater than the same parts of other groups. No differences were found between the group with accessory posts and only cemented posts in this root portion. No differences was observed comparing cervical e middle portions of different groups. The failure types after the push out test were observed in MEV with 200, 600 e 1000x magnification. They occurred exclusively between the post and the resin cement or the composite resin. A hybrid layer was more easily observed in the cervical and middle portions of the roots in all groups. This suggests that the retention in the apical portions of roots is mostly frictional. Since accessory posts only eventually can reach the middle portion of root canal the post retention is not increased with this technique.