The case histories of two patients are presented to demonstrate use of soft mouthguard appliances as carries for desensitizing dentifrice when restoration of the teeth or application of densitizing agents is clinically impractical. Potassium nitrate in dentifrice form was a readily available source of potassium ions for altering pulpal nerve sensitivity. Both patients had factitious habits that exacerbated dentinal hypersensitivity and required acute care.