Investigation of Factors Influencing Stain Formation Utilizing an in Situ Model

Abstract

In order to understand the factors of extrinsic stain formation more fully, we have developed an in situ stain model. This consists of polished bovine enamel blocks attached to partial or full dentures worn by adult volunteers for 24 h per day. The dentures were cleaned twice daily with a commercial dentifrice and toothbrush, with care taken to avoid brushing the inserts. A Minolta CR321 Chroma Meter in the L*a*b* mode was used for taking reflectance measurements of the stain formed on the enamel inserts. From these values, changes in the color of the inserts were calculated and the level of stain determined. In general, the stain formed on the enamel inserts was yellow and increased in intensity and darkness with time. The enamel inserts with the largest stain increases were from smokers rather than non-smokers. No correlation was observed between amount of stain and quantity of tea and coffee consumed. When the effects of surface roughness on in situ stain formation were considered, the major variable in this study was found to be the location of the enamel insert in the denture rather than the surface roughness.