In vitro and clinical evaluation of optical tooth whitening toothpastes.

OBJECTIVES: To measure tooth whitening effects delivered immediately after brushing with silica-based toothpastes containing either blue covarine or a combination of blue covarine and FD&C Blue No. 1 in vitro and in vivo. METHODS: Salivary pellicle coated human extracted teeth were brushed with either a slurry of a toothpaste containing blue covarine (BC) or a formulation containing a matched level of blue covarine and FD&C Blue No.1 (BC+D). The colour of the specimens were measured in vitro using a colorimeter, before and after brushing and changes in CIELAB and tooth Whiteness Index (WIO) values calculated. In a double-blind cross-over clinical study, subjects brushed with BC toothpaste, a toothpaste containing increased levels of blue covarine (BC+) or BC+D toothpaste and tooth colour changes were measured with a digital image analysis system. RESULTS: The in vitro study demonstrated that BC+D gave a significantly (p=0.002) greater change in WIO value than BC. Clinical results showed that BC, BC+ and BC+D gave a significant increase in WIO (p<0.0001) from baseline. The WIO change was significantly greater when brushing with BC+D toothpaste than with either toothpaste BC (p<0.0001) or BC+ (p<0.05). CONCLUSIONS: Toothpastes containing blue covarine or a combination of blue covarine and FD&C Blue No. 1 gave a statistically significant improvement in tooth whiteness immediately after brushing in both in vitro and clinical studies. In addition, the toothpaste containing both blue covarine and FD&C Blue No. 1 gave statistically significant greater tooth whitening from baseline than the blue covarine containing toothpastes. CLINICAL SIGNIFICANCE: The silica-based toothpastes containing blue covarine or a combination of blue covarine and FD&C Blue No. 1 evaluated in the current study gave significant tooth whitening benefits immediately after one brush.

Mapping biological to clinical phenotypes during the development (21 days) and resolution (21 days) of experimental gingivitis.

AIM: To characterize and map temporal changes in the biological and clinical phenotype during a 21-day experimental gingivitis study. MATERIALS AND METHODS: Experimental gingivitis was induced over 21 days in healthy human volunteers (n = 56), after which normal brushing was resumed (resolution phase). Gingival and plaque indices were assessed. Gingival crevicular fluid was collected from four paired test and contra-lateral control sites in each volunteer during induction (Days 0, 7, 14 and 21) and resolution (Days 28 and 42) of experimental gingivitis. Fluid volumes were measured and a single analyte was quantified from each site-specific, 30s sample. Data were evaluated by analysis of repeated measurements and paired sample tests. RESULTS: Clinical indices and gingival crevicular fluid volumes at test sites increased from Day 0, peaking at Day 21 (test/control differences all p < 0.0001) and decreased back to control levels by Day 28. Levels of four inflammatory markers showed similar patterns, with significant differences between test and control apparent at Day 7 (substance P, cathepsin G, interleukin-1ß, elastase: all p < 0.03) and peaking at Day 21 (all p < 0.002). Levels of α-1-antitrypsin showed no pattern. CONCLUSIONS: Levels of substance P, cathepsin G, interleukin-1ß and neutrophil elastase act as objective biomarkers of gingival inflammation induction and resolution that typically precede phenotypical changes.