This study is a double-blind, randomized, placebo-and positive-controlled, stratified parallel group clinical trial. The three groups will be randomly assigned to use one of three test toothpastes having an identical base formulation but containing respectively either 0% nano-hydroxyapatite (HAP) (placebo), 15% nano-HAP or 5% KNO3 (positive control). All dental examinations for data collection will be conducted by the same Clinical Examiner.
Subjects will be enrolled into 3 balanced groups each using a different strength toothpaste. Dental hypersensitivity (DHS) will be assessed at study start, midway and study end.