Resumo

CASTELLAN, Carina Strano  e  CARDOSO, Paulo Eduardo Capel. Evaluation of different bond strength tests on fiber posts' adhesion. RPG, Rev. pós-grad. [online]. 2011, vol.18, n.3, pp. 127-133. ISSN 0104-5695.

The purpose of the present study was to compare microtensile (Mi), push-out (Ps) and pull-out (Pl) tests in the ability to accurately measure the bond strength of fiber posts luted inside root canals, using two different adhesives, Optbond S Plus/Kerr (OS) and Optbond Solo Self Ecth/Kerr (OSE), at different root dentin levels, cervical, middle and apical. Eighteen human intact single-rooted and endodontically treated teeth were divided into two groups according to the adhesive system used. Both adhesive systems were used in combination with Variolink II (Ivoclar-Vivadent). Teeth were, than, divided in three groups depending on the type of test performed: Mi, Ps or Pl. All samples were perpendicularly sectioned into 1 mm thick sections. For Ps and Pl tests, samples were disc shaped, and the bond strength between post and dentin was measured in the root slice and the force applied on the center of the specimen. For the Mi test hourglass-shaped, samples were obtained by trimming the proximal surfaces of each slice using a diamond bur until it touched the post. All specimens were submitted to a bond strength test at 0.5 mm/minute crosshead speed in a universal testing machine. Statistically significant difference was found only amid the different tests (Mi = 5.93 ± 2.00a; Pl = 6.11 ± 2.82a; Ps = 9.50 ± 4.05b). The push-out test provided higher values of bond strength for root dentin and fiber post when compared to the values obtained by the microtensile and pull-out tests. No statistically significant differences were found either among the two adhesives or among root levels.

Palavras-chave : Dental pins; Dentin-bonding agents; Dentin.