Dureza Knoop e resistência da união de cimentos resinosos após a fixação de pinos de fibra em diferentes condições técnicas e regiões da raiz / Knoop hardness and bond strength of resin cements after fixing fiber posts in different technical conditions and regions of root

AUTOR(ES)
DATA DE PUBLICAÇÃO

2011

RESUMO

The objective of this study was to evaluate the bond strength through the push-out test and Knoop microhardness of resin cements after fixation of fiber posts, in the manners conventional, with a flared root and with composite resin relined post, according to root area. From the 60 bovine incisor roots, forty were weakened with diamond bur #4137, and all were endodontically treated. One week following the endodontic treatment, the post space was prepared for size 3 D.T. Light Post luting, according to groups: G1- conventional cementation with Scotchbond Multi- Purpose Plus (SBMP)/RelyX ARC (ARC), G3- fiber post luted at the flared root with SBMP/ARC; G5- relined post luted at the flared root with SBMP/ARC. In groups 2, 4 and 6 posts were luted in the same manner with the adhesive system All Bond 3 and C&B Cement resin cement. After 24 hours, the roots were transversely sectioned and 2 slices per region of post space (cervical, middle and apical) were obtained. One was used to evaluate the microhardness and the other for the pushout test, at 0.5mm/min. performed at Instron testing machine. Data were analyzed with ANOVA (3-way) and means compared by Tukey test (5%). For the microhardness test, no significant differences were found among regions for the two groups in the three studied conditions. The hardness of the groups luted with C&B Cement was higher than the groups with RelyX ARC in the three conditions studied. For the groups luted with RelyX ARC, the bond strength in the cervical region was upper than middle and apical regions. For groups luted with C&B Cement the bond strength was higher in the cervical region compared to the apical. The groups luted with C&B Cement had greater bond strength than those cemented with RelyX ARC. In the RelyX ARC luted groups, the relined post group had higher bond strength than conventional and flared root groups. The relined group in C&B Cement gained greater bond strength than the conventional group. Failure mode was predominantly adhesive at resin cement and dentin interface. It was concluded that the relining fiber post with composite resin improved the union of fiber post to root canal and did not impair the microhardness of resin cement. The chemically cured resin cement obtained more homogeneous hardness values and bond strength than the dual-cured cement. The bond strength in the cervical region was higher than the apical region

ASSUNTO(S)

cimentos de resina tecnica para retentor intra-radicular materiais dentários resin cements post and core technique dental materials

ACESSO AO ARTIGO

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