Evidence suggests that patients suffer the painful symptoms of
dentine hypersensitivity when dentine is exposed and the dentinal tubule system is opened to the oral cavity to allow stimuli to trigger a neural response in the pulp via a hydrodynamic mechanism. The processes needed to localise lesions of
dentine hypersensitivity include loss of enamel and/or
gingival recession. Whilst tooth brushing with or without
toothpaste appears to cause minimal wear to enamel (in the absence of
acids), circumstantial evidence implicates tooth brushing with
gingival recession and exposure of dentine. Other
tooth wear processes notably attrition and
acid erosion cause loss of enamel and can expose dentine. Therefore sensitivity may result. How lesions of
dentine hypersensitivity are initiated is a matter of conjecture and based on extrapolating data from studies, mainly in vitro, to affect in vivo. Again this circumstantial type of evidence suggests that abrasion by some
toothpastes and erosion by dietary
acid could open the tubule system. Little is known about the actual effect of desensitising
toothpastes on lesions of
dentine hypersensitivity even though they are formulated to either occlude dentinal tubules or block the neural response in the pulp. Clinical studies have produced contradictory findings for the efficacy of products and there have been extremely few evidence based reviews. In conclusion, available evidence supports a probable link of tooth brushing, with or without
toothpaste and an acidic diet to both
tooth wear and
dentine hypersensitivity, and suggests also that
dentine hypersensitivity is a
tooth wear phenomenon. Although there is a need for more direct clinical and scientific evidence for these associations, it is recommended that they be taken into consideration when planning management strategies for the
dentine hypersensitivity sufferer.