Interproximal stains and plaque are often hard to reach with scalers, and the use of abrasive finishing and polishing strips to remove surface stains damages tooth enamel.
After the cementation of crowns, all the visible cement is removed and floss passes smoothly, making it easy to assume that all of the cement has been cleaned up. But as a final check, when an x-ray is taken, a little piece of resin cement is found just below the proximal contact area, hidden in the subgingival area and stuck to the enamel surface.
Tea or coffee stains between crowded, lower anterior teeth are very common and can be hard to reach with scaler tips. My hygienists worked diligently to remove tiny traces of stains that were inevitably left, but found the task very difficult. This on-going problem inspired me to develop the ContacEZ Pink Strip.