ROMANIAN JOURNAL OF STOMATOLOGY – VOLUME 69, NO. 3, 2023 169 SEM and EDS comparative studies about the homogeneity of some cements used for luting of posts Gina Paunita Grecu 1 , Doina Lucia Ghergic 1,2 , Raluca Monica Comaneanu 1,2 , Claudia Florina Bogdan-Andreescu 2 , Cherana Gioga 2 , Irina Maria Gheorghiu 3 , Anna Maria Pangica 2 , Paula Perlea 3 , Mihail Tarcolea 4,5 1 Doctoral School of Dental Medicine, “Titu Maiorescu” University of Bucharest, Romania 2 Department of Dental Medicine Specialty Disciplines, Faculty of Dental Medicine, “Titu Maiorescu” University of Bucharest, Romania 3 “Carol Davila” University of Medicine an Pharmacy Bucharest, Romania 4 BIOMAT Research Center, POLITEHNICA University of Bucharest, Romania 5 Doctoral School of Materials Science and Engineering, POLITEHNICA University of Bucharest, Romania Corresponding author: Raluca Monica Comaneanu E-mail: monica.comaneanu@prof.utm.ro ENDODONTICS ABSTRACT Objectives. The aim of the study was to evaluate comparatively by scanning electron microscope (SEM) and ener- gy dispersive spectrophotometry (EDS) the physical and chemical homogeneity of some luting materials used for cementation of three types of posts. Materials and method. We selected 12 irretrievable monoradicular teeth extracted in our dental offices. After ex- traction, all teeth were prepared for cementation with 4 different cements (NANOCORE DUAL, CEMBEST, PANAVIA SA and CEMENT-ONE) of three types of posts: prefabricated titanium post, FibreKleer 4x fiberglass post (Pentron) and post cast from NiCrMo alloy. Afterwards, the samples were embedded in resin and prepared metallographically for examination with the Phenom ProX scanning electron microscope equipped with an energy dispersive spectro- photometer with X Rays. Results. SEM studies provide valuable ultrastructural information regarding the degree of filling with luting materi- als. The four studied cements do not present an inhomogeneous composition in the EDS analysis, not having signif- icantly increased values between the 2 analyzed points for each of the 12 samples taken in the study. Conclusions. Among the four luting materials studied comparatively, PANAVIA SA seems to best fill the existing spaces between posts and the limits of dental preparations, being closely followed by CEMENT-One and CEMBEST. In last place is NANOCORE DUAL, which presents discontinuities in the mass of material and at the border with the preparations. Keywords: SEM, EDS, fiberglass post, titanium post, casting post, luting materials Ref: Ro J Stomatol. 2023;69(3) DOI: 10.37897/RJS.2023.3.1 Article History: Received: 20 June 2023 Accepted: 27 June 2023 INTRODUCTION Selecting the optimal way to restore endodonti- cally treated teeth is still a controversial topic, which is intensely debated in the specialized literature. Un- like vital teeth, endodontically treated teeth have substantially different mechanical properties [1]. These changes are due to the quantitative loss of hard substance both through the expansion of the carious processes themselves and through the preparation of the access cavities necessary for en- dodontic therapy [2,3]. Endodontically treated teeth present a higher risk of fracture compared to vital teeth [4] and therefore preserving as much of the hard dental structure as possible is essential to es- tablish and maintain a balance between biological, mechanical, adhesive, functional and aesthetic pa- rameters [5]. In recent years, the restorative ap- proach to endodontically treated teeth has changed. The development of dental adhesive techniques has expanded the therapeutic options of clinicians. The