Soft-tissue alterations following exposure to tooth-whitening agents.

BACKGROUND: Tooth-whitening agents are widely used, either as self-application products or under the supervision of a dentist. These products may be associated with transient gross morphologic changes in oral soft tissues. However, their potential effects on human keratinocytes and fibroblasts in a stratified squamous epithelium have yet to be elucidated. METHODS: In this study, three-dimensional human tissue equivalents are exposed to varying concentrations of tooth-whitening agents for increasing time periods. Tissue alterations are investigated in terms of morphology, proliferation, apoptosis, and protein expression. RESULTS: All whitening agents tested altered tissue morphology, induced proliferation of basal keratinocytes, and caused apoptosis of cells in all epithelial strata. In addition, whitening agents induced alterations in the expression of cytokines that are linked to inflammation. CONCLUSIONS: These results suggest that whitening agents may induce similar changes in vivo and that these products should be used for limited periods of time or under the supervision of a dental professional.

Do bib clips pose a cross-contamination risk at the dental clinic?

Although multiple-use dental napkin holders have a relatively low risk of transmitting infection, they do require disinfection between patients. This study sought to: 1) determine the presence of bacterial load on two types of clips of reusable bib chains after dental procedures at the Endodontics and Orthodontics clinics at Tufts University School of Dental Medicine; and 2) evaluate the effectiveness of disinfecting the clips. These specialty clinics represent a wide spectrum of patients, procedures, and appointment times. Bacterial load on the bib clips was determined immediately following dental treatments-both before and after their disinfection-during morning and afternoon sessions. The results revealed that, after treatments, there was a statistically significant difference when comparing the two clinics for bacterial burden on the clips. Furthermore, there was a statistically significant difference in bacterial load on the two types of clips. Disinfection of the bib clips was highly effective in both clinics. Clinically, the results suggest that due to the nature of the treatment, the demographic population, and the type of bib clips used, patients in different clinics may be exposed to varying bacterial concentrations on the bib clips, and thus to different possible cross-contamination risks. Future analyses will be performed to identify the bacterial species in samples from both pre- and post-disinfected clips, and to determine if they harbor disease-causing bacterial species that can pose a potential, yet undetermined risk for cross-contamination.