[Morphologic evaluation of adhesive/resin cement system and fiber post: a sem investigation]

The purpose of the present paper is to carry out an SEM investigation into the adhesive cementation of quartz fibre posts in canals treated with endodontic cements containing or not containing eugenol.

Sixteen selected tooth roots were subdivided into 4 groups and prepared with the step-back technique. Group A, without canal filling and with a cemented post, was the control group; in groups B and C, the canals were closed with guttapercha, endomethasone C and eugenol, those of group D with guttapercha and AH Plus without eugenol. The canals were prepared so as to be able to take D.T. light-posts irrigated with water (group C with ethyl alcohol) mordanted with orthophosphoric acid after applying 2 layers of photopolymerised ONE-STEP; 2 layers of ONE-STEP were applied to the post. DUO-LINK cement was positioned in the canal after inserting the post, removing excess resin and photopolymerising. The samples were prepared for SEM observation.

Group A: the apical portion shows the post absorbed into the cement and resin tags; group B: porosity is noted between cement and post, the hybrid layer does not present tissue penetration of the dentin resin; group C: bullae can be seen between cement and post surface and between hybrid layer and cement; group D: there is relative continuity between post surface, cementing resin, hybrid layer and underlying dentin.

The study has shown that eugenol interferes with the formation of the hybrid layer, the pictures relative to the resinous cement appeared different depending on whether the canal was treated with cement containing or not containing eugenol.