STAIN REMOVAL EFFICACY - AN IN-VITRO EVALUATION USING QUANTITATIVE IMAGE-ANALYSIS

Objective: This study developed a computer image analysis technique as a quantitative means to measure changes in dental stain after brushin g with various dentifrices. Method and materials: Enamel specimens wit h naturally occurring mature stain were cut from bovine incisors. The specimens were subjected to in vitro toothbrushing with one of the fou r tested groups, consisting of two dentifrices that make claims of sta in removal (Aquafresh Whitening and Rembrandt Sensitive), a regular de ntifrice, (Aquafresh Triple Protection), and water. Digital images of stain specimens were recorded under standardized lighting conditions a nd analyzed with an image analysis software. The area-intensity stain determinant, which accounted for the reflected intensity and the corre sponding areas of stain, was computed. Stain removal efficacy was calc ulated based on the difference in area-intensity stain determinant bef ore and after brushing. Results: Brushing with any of the tested denti frices removed more stain than did brushing in water alone. The findin g that brushing with a regular dentifrice resulted in a higher stain r emoval efficacy than brushing with water seems to indicate a role for abrasivity. Aquafresh Whitening had a higher stain removal efficacy th an did Rembrandt for the removal of mature calcified stain used in thi s study. However, there were certain stains that none of the dentifric es removed. Conclusion: Computer image analysis provides an objective and quantitative measurement to distinguish in vitro stain removal eff icacy of dentifrices.