Efficacy of mouth rinses and toothpaste on tooth whitening.

OBJECTIVES: People increasingly desire tooth whitening. Considering the wide range of whitening products on the market, this study evaluated the efficacy of whitening toothpastes and mouth rinses compared with the 10% carbamide peroxide (CP) whitening gel. METHODS: We obtained 120 cylindrical specimens from bovine teeth, which were darkened for 24 hours in a coffee solution. The color measurement was performed by a spectrophotometer using the CIE L*a*b* system, and specimens were divided into six groups according to the use of the following agents: group 1, conventional fluoridated toothpaste; group 2, Close Up White Now; group 3, Listerine Whitening; group 4, Colgate Plax Whitening; group 5, experimental mouth rinse with Plasdone; and group 6, 10% CP Whiteness Perfect. After the simulation of 12 weeks of treatment for groups 1 to 5 and 14 days of treatment for group 6, the specimens were subjected to a new color reading. RESULTS: Data were subjected to one-way analysis of variance (α=0.05), which showed significant differences among groups after 12 weeks for ΔE (p=0.001). Results of the Tukey test revealed that groups 3, 4, and 6 presented significantly higher color alteration than groups 1, 2, and 5. CONCLUSIONS: The whitening toothpaste Close Up White Now and the experimental mouth rinse with Plasdone showed similar color alteration as conventional toothpaste after a 12-week treatment simulation. These groups presented significantly lower color alteration compared with whitening mouth rinses Listerine and Colgate Plax Whitening, which showed similar results to those observed after 14 days of bleaching with 10% CP treatment.

Molecular biology of myeloma.

Multiple myeloma (MM) is a B-cell malignancy characterised by the accumulation of clonal plasma cells (PC) in the bone marrow (BM). The molecular bases for this incurable disease have been widely investigated in the last years, and the development of modern genomic technologies has contributed to the understanding of the pathogenesis of MM. The molecular mechanisms that explain the cellular origin of myeloma cells, the cytogenetic abnormalities and their clinical implications, and the biological information provided by gene expression profiling analysis are reviewed in this paper. In addition, a molecular classification of MM in seven groups based on the relationship between gene expression profiling, chromosomal translocations and prognostic outcome is also presented. And finally, the recent hypothesis of a potential unifying event in the pathogenesis of MM, supported by cyclin D deregulation in virtually all MM tumours, will be summarised.