- At Visit 1 (Screening): a) Self-reported history of DH lasting more than six months but not more than 10 years. b) Minimum of 20 natural teeth. c) Minimum of 2 accessible non-adjacent teeth (incisors, canines, pre-molars), preferably in different quadrants, that meet all of the following criteria: -Signs of facial/cervical gingival recession and/or signs of erosion or abrasion (EAR). -Tooth with modified gingival index (MGI) score =0 adjacent to the test area (exposed dentine) only [Lobene, 1986] and a clinical Tooth with signs of sensitivity measured by qualifying evaporative air assessment (Y/N response) mobility of ≤1, -Tooth with signs of sensitivity measured by qualifying evaporative air assessment (Y/N response)