Authors' reply

Thank you for your very pertinent questions which are highly relevant. The fact is that we do not know how often to disturb the biofilm. We do not know if it alone is sufficient to influence initiation of lesions. All we know is that, if you ensure that fluoride is available in the oral cavity (from fluoride toothpastes, water, etc) whenever there are pH fluctuations in the biofilm we can influence the de- and re-mineralization dynamics. However, regular (once or twice daily) oral hygiene removes excessive amounts of what we used to call dental plaque or disturbs the biofilm so that this facilitates fluoride ion access to the interface between enamel and biofilm.

When it comes to established cavities, we have since the days of Black and later Anderson, Massler and others, known that removal of the plaque/biofilm in the cavities is sufficient to arrest further lesion progression. Again, if the fluoride ion activity is slightly elevated in the oral fluids, it helps significantly. Example: occlusal cavities should be ‘opened up’ to facilitate keeping the cavity clean – eventually by mastication – and further lesion progression is inhibited. This is ‘old’ knowledge which has been largely ignored since we had the high-speed drill entering the market almost 60 years ago. This is the case in both dentitions and, if appreciated, could prevent children from having a lot of drilling and filling.