Dentine remineralization induced by two bioactive glasses developed for air abrasion purposes Zhejun Wang a,b , Tao Jiang b , Salvatore Sauro c,d , Yining Wang b , Ian Thompson c , Timothy F. Watson c , Yue Sa b , Wenzhong Xing b , Ya Shen a , Markus Haapasalo a, * a Division of Endodontics, Oral Biological & Medical Sciences, School of Dentistry, University of British Columbia, Canada b The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, 237 Luoyu Road, Wuhan 430079, PR China c Biomaterials, Biomimetics & Biophotonics Department, King’s College London Dental Institute, Guy’s Dental Hospital, London UK d Department of Dental Materials, School of Dentistry, University of Granada, Campus de Cartuja s/n. E-18071 Granada, Spain 1. Introduction Dentine is a tubular permeable structure composed of organic matrix embedded in crystalline apatite which accounts for the most part of dental hard tissues. 1 Although a physiological equilibrium exists between remineralization and deminerali- zation of the dental hard tissues in the oral cavity, an increase in organic acids derived from dental plaque or an acidic diet j o u r n a l o f d e n t i s t r y 3 9 ( 2 0 1 1 ) 7 4 6 – 7 5 6 a r t i c l e i n f o Article history: Received 27 April 2011 Received in revised form 30 July 2011 Accepted 7 August 2011 Keywords: Bioactive glass Dentine Remineralization ATR-FTIR a b s t r a c t Objectives: The present study aimed to evaluate dentine remineralization through a 7-day period of artificial saliva (AS) storage induced by bioactive glass 45S5 (BAG) and by bioactive glass modified with soda-lime spherical glass. Methods: Partially demineralized dentine disks were treated by BAG or the spherical-glass modified bioactive glass (M-BAG) and subsequently immersed in AS for 7 days. Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR-FTIR) was used to quantita- tively analyse the mineral variation of the dentine surface by calculating the spectra parameters. X-ray diffraction (XRD) and energy-dispersive X-ray analysis (EDX) were per- formed on completely demineralized dentine to confirm the apatite formation. The rough- ness of the dentine surface was evaluated by atomic force microscopy (AFM) and the morphology was also examined by scanning electron microscopy (SEM). Results: ATR-FTIR showed a significant increase of the mineral matrix area ratio in dentine specimens treated with the two bioactive glasses subsequent to 7 days of AS storage. The XRD spectrum exhibited apatite growth and mineral elements could be found on completely demineralized samples analysed by EDX after remineralization treatments. The dentine specimens treated with bioactive glass showed lower roughness, and most of the dentinal tubules appeared completely occluded during the AFM and SEM examination. Conclusions: Although the concentration of bioactive glass in the M-BAG is 60% of that contained in the original version, both formulations have similar potential in dentine remi- neralization. These bioactive powders developed for air-abrasive use may be considered as innovative bioactive materials for therapeutic remineralization of dental hard tissues. # 2011 Elsevier Ltd. All rights reserved. * Corresponding author at: Division of Endodontics, Oral Biological & Medical Sciences, UBC Faculty of Dentistry, 2199 Wesbrook Mall, Vancouver, BC, Canada V6T 1Z3. Tel.: +1 604 822 5996; fax: +1 604 822 3562. E-mail address: markush@dentistry.ubc.ca (M. Haapasalo). available at w ww.s c ienc ed irec t.c o m journal homepage: www.intl.elsevierhealth.com/journals/jden 0300-5712/$ – see front matter # 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.jdent.2011.08.006