ORIGINAL ARTICLE Three-dimensional culture of dental pulp stem cells in direct contact to tricalcium silicate cements M. Widbiller 1 & S. R. Lindner 1 & W. Buchalla 1 & A. Eidt 1 & K.-A. Hiller 1 & G. Schmalz 1,2 & K. M. Galler 1 Received: 14 April 2015 /Accepted: 12 June 2015 /Published online: 1 July 2015 # Springer-Verlag Berlin Heidelberg 2015 Abstract Objectives Calcium silicate cements are biocompatible dental materials applicable in contact with vital tissue. The novel tricalcium silicate cement Biodentine™ offers properties su- perior to commonly used mineral trioxide aggregate (MTA). Objective of this study was to evaluate its cytocompatibility and ability to induce differentiation and mineralization in three-dimensional cultures of dental pulp stem cells after di- rect contact with the material. Materials and methods Test materials included a new tricalcium silicate (Biodentine™, Septodont, Saint-Maur- des-Fossés, France), MTA (ProRoot® MTA, DENSPLY Tulsa Dental Specialities, Johnson City, TN, USA), glass ionomer (Ketac™ Molar Aplicap™, 3M ESPE, Seefeld, Germany), human dentin disks and polystyrene. Magnetic ac- tivated cell sorting for to the surface antigen STRO-1 was performed to gain a fraction enriched with mesenchymal stem cells. Samples were allowed to set and dental pulp stem cells in collagen carriers were placed on top. Scanning electron microscopy of tricalcium silicate cement surfaces with and without cells was conducted. Cell viability was measured for 14 days by MTT assay. Alkaline phosphatase activity was evaluated (days 3, 7, and 14) and expression of mineraliza- tion-associated genes (COL1A1, ALP, DSPP, and RUNX2) was quantified by real-time quantitative PCR. Nonparametric statistical analysis for cell viability and alkaline phosphatase data was performed to compare different materials as well as time points (Mann- Whitney U test, α =0.05). Results Cell viability was highest on tricalcium silicate ce- ment, followed by MTA. Viability on glass ionomer cement and dentin disks was significantly lower. Alkaline phospha- tase activity was lower in cells on new tricalcium silicate ce- ment compared to MTA, whereas expression patterns of mark- er genes were alike. Conclusions Increased cell viability and similar levels of mineralization-associated gene expression in three- dimensional cell cultures on the novel tricalcium silicate ce- ment and mineral trioxide aggregate indicate that the material is cytocompatible and bioactive. Clinical relevance The tested new tricalcium silicate cement confirms its suitability as an alternative to MTA in vital pulp therapy. Keywords Tricalcium silicate . Mineral trioxide aggregate . Collagen type I . Multipotent stem cells . Dental pulp . Three-dimensional cell culture Introduction Biocompatible materials play an increasingly important role in the field of dental material science. In regards to tissue re- sponse, they are classified as either bioinert or bioactive [1]. Bioinert materials are tolerated by live tissues but may still elicit interposition of fibrous tissue and passive encapsulation G. Schmalz and K. M. Galler contributed equally to this work. Electronic supplementary material The online version of this article (doi:10.1007/s00784-015-1515-3) contains supplementary material, which is available to authorized users. * M. Widbiller matthias.widbiller@ukr.de 1 Department of Conservative Dentistry and Periodontology, University Medical Center, Franz-Josef-Strauß-Allee 11, D-93053 Regensburg, Germany 2 School of Dental Medicine, University of Bern, Freiburgstrasse 7, CH-3010 Bern, Switzerland Clin Oral Invest (2016) 20:237–246 DOI 10.1007/s00784-015-1515-3