Effect of desensitising toothpastes on dentinal tubule occlusion: A dentine permeability measurement and SEM in vitro study Zhejun Wang a , Yue Sa a , Salvatore Sauro b , Hao Chen a , Wenzhong Xing a , Xiao Ma a , Tao Jiang a,1, *, Yining Wang a,1, * a Key Laboratory for Oral Biomedical Engineering, Ministry of Education, School and Hospital of Stomatology, Wuhan University, 237 Luoyu Road, Wuhan 430079, PR China b Biomaterials, Biomimetics & Biophotonics Department, King’s College London Dental Institute, Guy’s Dental Hospital, London, UK 1. Introduction Dentine hypersensitivity is a common dental problem caused by the exposure of dentinal tubules which allow the movement of intradentinal fluid leading to dentine hypersen- sitivity. 1,2 The hydrodynamic hypothesis, proposed by Bra ¨ nn- stro ¨m et al., 3 has stimulated clinical research by suggesting two methods for desensitising dentine: (1) reduce the ability of journal of dentistry 38 (2010) 400–410 article info Article history: Received 20 October 2009 Received in revised form 10 January 2010 Accepted 15 January 2010 Keywords: Dentine hypersensitivity Desensitising toothpastes Dentine permeability Toothbrushing Citric acid Artificial saliva abstract Objectives: The purpose of this study was to evaluate the in vitro effectiveness of a new bioglass-containing and two commercial desensitising toothpastes on dentinal tubule occlusion after citric acid challenge or artificial saliva (AS) immersion. Methods: One hundred dentin discs from human third molars were used. Specimens were randomly divided into five groups (n = 20), Group 1: EDTA-treated dentin; Group 2: brushing with distilled water; Group 3: brushing with Novamin; Group 4: brushing with Sensodyne Freshmint; Group 5: brushing with Colgate Sensitive. In each group, samples were then equally split into two subgroups (n = 10) to test two post-treatments: 6% citric acid challenge or 24 h immersion in artificial saliva. Dentine permeability of each specimen was measured before and after each treatment using a hydrostatic device working at 20 cm H 2 O pressure. Data were analysed by two-way repeated measures ANOVA to determine if there were any significant differences within or between groups. Dentine morphology and surface deposits were observed by SEM. Results: All three desensitising toothpastes significantly reduced dentine permeability and created precipitates on the treated dentine surfaces. Moreover, the reductions in dentine permeability showed partial recovery after a citric acid and artificial saliva immersion. Sensodyne showed significant resistant to acid attack and Novamin exhibited the lowest permeability after artificial saliva immersion for 24 h. Conclusions: The application of the three toothpastes resulted in effective dentinal tubule occlusion. However, the new bioglass-containing toothpaste (Novamin) represented excel- lent occlusion effects after brushing treatment and AS immersion, while Sensodyne dem- onstrated more reduction in permeability when citric acid challenged. # 2010 Elsevier Ltd. All rights reserved. * Corresponding authors. Tel.: +86 27 87646315; fax: +86 27 87873260. E-mail addresses: jiangtao2006@whu.edu.cn (T. Jiang), wang.yn@whu.edu.cn (Y. Wang). 1 Both authors contributed equally to this work. available at www.sciencedirect.com journal homepage: www.intl.elsevierhealth.com/journals/jden 0300-5712/$ – see front matter # 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.jdent.2010.01.007