Trial of Nano-hydroxyapatite-Containing Toothpastes for Relief of Dentin Hypersensitivity

Inclusion Criteria: * Males or females between the age of 20 and 80 years, of any socio-economic status * Diagnosed as having DHS, i.e. having at least one sensitive tooth with demonstrated cervical erosion/abrasion or gingival recession * Showing a sensitivity response to both tactile and cold air stimulus delivered by a Yeaple probe and a one-second blast of cold air respectively * Patients must be reliable, cooperative and of adequate intelligence to read and understand the rating scales and other study instructions * Patients must be able to read, comprehend, and sign the informed consent form * The teeth and sites to be tested should be on the buccal/labial surfaces of incisors, canines, premolars or molars where the affected sites are accessible * Teeth selected for testing should have a plaque index of ≤ 2 Exclusion Criteria: * The sensitive tooth is associated with concomitant oral pain due to any other condition such as soft-tissue lesions, tooth-ache ascribable to dental caries, tooth fracture, or cracked tooth syndrome, or pain due to other surgical procedures or injuries. * The sensitive tooth is associated with a periodontal abscess as diagnosed from an X-ray or clinical examination of the tooth * The sensitive tooth is associated with mobility \>1 * The sensitive tooth is associated with gum pain from gingivitis, occlusal trauma, thermal or chemical burns * Patients having pain from periodontal-related causes but not DHS * Previous professional desensitizing treatment * Patients using medication which could interfere with the perception of pain * Medical histories marked by chronic use of anti-inflammatory agents, daily analgesics, anticonvulsants, antihistamines, antidepressants, sedatives and/or other psychotropic drugs * Pregnancy or breastfeeding * Allergies and idiosyncratic responses to toothpaste ingredients * Eating disorders or conditions associated with vomiting * Systemic conditions that are etiologic or predisposing to DHS * Excessive dietary or environmental exposure to acids * The sensitive tooth was restored in the preceding three months * The sensitive tooth is an abutment tooth for fixed or removable prostheses * The sensitive tooth has extensive restoration or restorations extending into the test area * Patients below 20 years or above 80 years of age * Smokers