Comparison of Mechanism of Action of Desensitizing Treatments

Sequential application of ACP-forming solutions, consisting of, first, calcium chloride and, then, potassium phosphate/sodium fluoride, is approved as a professional desensitizer, which relieves hypersensitivity by occluding tubules. Objective: The study compared tubule occlusion by a single application of the clinically-proven professional desensitizer with multiple treatments by each of three clinically-proven desensitizing toothpastes, which also deliver Ca++ and phosphate ions to the tooth surface. Method: Fluid flow through coronal dentin disks mounted in Pashley cells was measured before and after a single treatment with a professionally applied desensitizer, Quell®, or multiple treatments by one of three desensitizing fluoride-dentifrices, Enamelon ®, Arm & Hammer® Enamel Care®, and a new sensitive toothpaste being marketed in the UK, Arm &Hammer Dental Care Sensitive®, all of which deliver calcium, phosphate, and fluoride to the tooth surface. SEM and EDX analyses of untreated dentin and the dentin after treatment were performed. Results: SEM scans show the professional desensitizer and all three toothpastes deposit mineral on the surface of the dentin and block the tubules. EDX indicates the mineral to contain Ca++ and phosphate in a ratio consistent with ACP formation. The loss of the carbon peak in treated dentin indicates coverage of the dentin by mineral. All compositions reduced fluid flow in dentinal tubules to a greater degree than a conventional toothpaste (Crest®). Conclusion: The desensitizing mechanism of the toothpastes is similar to that of the professional desensitizer. ACP formed on the dentin surface blocks tubules thereby desensitizing teeth.