Pull-out bond strength of a fibre-reinforced composite post system luted with self-adhesive resin cements Vassiliki Nova a , Lamprini Karygianni a , Markus J. Altenburger a , Martin Wolkewitz b , Andrej M. Kielbassa c,1, *, Karl-Thomas Wrbas a,c,1 a Division of Operative Dentistry and Periodontology, University School and Dental Hospital, University Medical Center Freiburg, Albert-Ludwigs-University, Freiburg i. Br., Germany b Institute of Medical Biometry and Medical Informatics, Albert-Ludwigs-University, Freiburg i. Br., Germany c Centre for Operative Dentistry and Periodontology, University of Dental Medicine and Oral Health, Danube Private University (DPU), Krems, Austria j o u r n a l o f d e n t i s t r y 4 1 ( 2 0 1 3 ) 1 0 2 0 – 1 0 2 6 a r t i c l e i n f o Article history: Received 27 July 2013 Received in revised form 13 August 2013 Accepted 17 August 2013 Keywords: Fibre post Self-adhesive cement Self-etch cement Pull-out test Cement thickness a b s t r a c t Objectives: Due to morphological differences along the root canal, serious structural dam- age, or extensive endodontic preparation, cement thickness of luted fibre-reinforced com- posite (FRC) post systems can largely vary. This study aimed at evaluating the effects of a self-etch (Multilink Automix, MLA) and various self-adhesive resin cements (G-Cem, GCM; Maxcem Elite, MXE; RelyX Unicem, RLX; SmartCem 2, SMC) on the pull-out bond strengths of FRC posts to root canal dentine, and to compare the effects of different cementation thicknesses. Methods: 100 bovine incisor roots were embedded in acrylic resin and randomly assigned to two groups. Root canals of group 1 were prepared with RelyX Fiber Post drill size one (Ø 1.3 mm), whereas in group 2 drill size three (Ø 1.9 mm) was used to attain different cement thicknesses (thicknesses 1 and 2). Each group was then subdivided into five subgroups (n = 10). RelyX Fiber Posts size one (Ø 0.70 mm) were luted with the respective resin cements. All specimens were subjected to pull-out evaluation using a universal testing machine. Post surface areas covered with cement were measured by means of stereomicroscopy. Results: RLX revealed the significantly highest pull-out bond strengths in both groups ( p < 0.05), while MXE exhibited the significantly lowest pull-out bond strengths in group 2 ( p < 0.05). Main failure modes were determined as adhesive at the cement-post surface for all examined groups (except for SMC, group 2). Conclusions: The different resin cements influenced the pull-out bond strengths, whereas the cement thickness itself was not responsible for any differences. Clinical significance: Self-adhesive resin cements can provide an acceptable retention of FRC posts even in case of use with wider post space conditions. # 2013 Elsevier Ltd. All rights reserved. * Corresponding author. Tel.: +43 2732 70478; fax: +43 2732 70478 7060. E-mail address: andrej.kielbassa@dp-uni.ac.at (A.M. Kielbassa). 1 These authors contributed equally to this work. Available online at www.sciencedirect.com ScienceDirect journal homepage: www.intl.elsevierhealth.com/journals/jden 0300-5712/$ – see front matter # 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.jdent.2013.08.011