An Investigation of the Clinical and Histologic Effects of Selected Dentifrices on Human Palatal Mucosa

Abstract

A study was undertaken in 24 human volunteer subjects to determine the possible effects of selected commercially available dentifrices on clinically normal masticatory mucosa. An acrylic stent was fabricated which was designed to hold four test dentifrices in close apposition to the palatal tissues for 1 hour. Evaluation approximately 8 hours later revealed pathologic responses which were evident clinically and histologically. 1. Clinically, palatal tissues exposed to Crest were not distinguishable from control areas, while Colgate (mfp), MacCleans, and Ultra Brite produced erythematous changes which were statistically significant when compared with adjacent control sites. 2. Histologically, epithelial changes were seen within the test sites which ranged from a parakeratin-like surface layer to necrosis and intraepithelial abcess formation. Control sites consisted of normal orthokeratinized palatal mucosa in all cases. 3. The more severe microscopic reactions were noted with MacCleans and Ultra Brite, while the milder reactions were associated with Colgate (MFP). Crest infrequently produced a parakeratin-like response. The response was not statistically significant when compared with controls. 4. The clinical and histologic reactions were generalized throughout the test population, suggesting that the responses were not due to individual hypersensitivity but due to irritation from one or more of the dentifrice components. Although the clinical significance of these findings could not be readily assessed, the potential for irritation of human palatal mucosa by selected dentifrices has been demonstrated. These findings support the suggestion by the World Workshop in Periodontics (1966)20 that efforts should be directed to the development of dentifrice materials less harsh to the oral tissues.