Adhesive strength in cementing fiberglass posts using different adhesive systems

The objective of this work was to evaluate the influence of the Scotchbond MP and Clearfil SE adhesive systems on the bond strength in the push out test between the fiberglass post and the root canal.

This in vitro study involved 20 human canine teeth extracted over a 12-month period. For inclusion in the sample, upper canine teeth with fully formed apices and curvatures less than 45° were considered. Teeth containing a calcified canal, with radiographically visible double curvature or that had undergone previous endodontic treatment were excluded from the sample. After selection, surface prophylaxis was performed using an ultrasound insert, followed by smoothing with a Gracey curette. Endodontic treatments were performed by a calibrated operator, following a pre-established protocol. Next, preparation of the root canal began to receive the Whitepost DC number 2 fiberglass post by removing 2/3 of this space. Next, the posts were prepared to be cemented, they were cleaned with 70% alcohol and conditioned with 37% phosphoric acid before receiving two layers of silane. From that moment on, the elements were randomly divided into two groups, according to the adhesive system, with RelyX ARC cement being used: Group SCB: Scotchbond MP and Group CFL: Clearfil SE. After cementing the fiber posts, the test specimens were prepared for mechanical testing using the push out test on the Universal Testing Machine (EMIC). Multiple comparisons were performed using the Tukey test. Statistical calculations were conducted adopting a significance level of 5%.

The two-factor analysis of variance demonstrated that there was no statistically significant interaction between the factors studied, however the use of the SCB Group adhesive system produced higher RU values.

It was concluded that greater bond strength was obtained between resin cement and root dentin when ScotchBond adhesive was used and there were no differences in RU in the different root portions. Key words:Fiberglass posts, Adhesive systems, Tensile strength, Cementation, Dental prosthesis.