Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 14 4 2017 10 30 212 223 EN Mahshid Saffarpour Assistant Professor, Department of Operative Dentistry, School of Dentistry, Alborz University of Medical Sciences, Karaj, Iran Maryam Mohammadi Assistant Professor, Department of Operative Dentistry, School of Dentistry, Alborz University of Medical Sciences, Karaj, Iran Mohammadreza Tahriri Assistant Professor, Dental Research Center, School of Dentistry, Marquette University, Milwaukee, WI, USA Azadeh Zakerzadeh 3 Assistant Professor, Department of Operative Dentistry, School of Dentistry, Qazvin University of Medical Sciences, Qazvin, Iran 2017 04 16 2017 09 05 Objectives: This study assessed the efficacy of modified bioactive glass (MBG) for dentin remineralization and obstruction of dentinal tubules. Materials and Methods: Thirty-six dentin discs were made from 20 third molars and were stored in 12% lactic acid solution for two weeks to induce demineralization. The samples were divided into three groups (n=12): 1- BG, 2- BG modified with 5% strontium (Sr) and 3- BG modified with 10% Sr. After applying the BG, the samples were stored in artificial saliva for 7, 14 and 21 days. Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy (ATR-FTIR), X-ray Diffraction (XRD) analysis, Scanning Electron Microscopy (SEM), and Energy-Dispersive X-ray (EDX) analysis were used to assess remineralization. Also, 6 dentin discs were divided into three groups of BG, BG modified with 5% Sr and BG modified with 10% Sr, to examine tubular occlusion. The discs were etched using 0.5M of EDTA for two minutes and were stored in artificial saliva for 7 days. Changes in dentin surface morphology were evaluated under SEM. Results: Group 3 showed high rates of remineralization at days 7 and 14, although the rate decreased at day 21. Group 2 exhibited high rates of remineralization at days 7, 14 and 21. Dentinal tubules were partially occluded by BG and BG modified with 5% Sr, while they were almost completely obstructed after the use of BG modified with 10% Sr. Conclusions: Strontium increases remineralization. Addition of 10% Sr to BG enhances apatite formation; however, the apatite dissolves over time. Addition of 5% Sr to BG stabilizes the apatite lattice and increases the remineralization. https://fid.tums.ac.ir/index.php/fid/article/view/1847 https://fid.tums.ac.ir/index.php/fid/article/download/1847/964