more effective than manual brushes in plaque removal and control of gingivitis (Heanue et al. 2003 , Robinson et al. 2005 , Yacoob et al. 2014 , Van der Weijden & Slot 2015 ). Although the total amount of tooth brushing over time has been thought to play a causal role in the development of gingival recession (Hirschfeld 1931 ), in the present 3‐year study no group differences emerged and neither the use of a power brush nor a manual brush was accompanied by increased gingival recession. On the contrary, there was evidence of reduced gingival recession with both brushes. It seemed likely that the procedures followed in this study resulted in improved tooth brushing behaviour and that this, in turn, reduced gingival recession. It has been suggested that with an improved technique, along with some slight reduction in gingival inflammation, there can be an element of creeping buccal attachment more usually seen after mucogingival surgery (Rajapakse et al. 2007 ). This offers a possible explanation for the reversal of gingival recession found in this study. Conclusions The findings of this study of the effects of toothbrushing on pre‐existing gingival recession are clear and compelling: Over a period of approximately 3 years of regular twice‐daily brushing, there was a significant and sustained reduction in gingival recession in both the group using a power toothbrush and the group using a manual brush. Over the same period, there was no difference in the amount of gingival recession between the two groups. Long‐term reductions in gingival recession may have been caused by sustained improvements in brushing technique due to the “Hawthorne Effect”. A regimen of 2 min. power or manual tooth brushing carried out daily, appears to have no adverse effects on gingival recession; it may even serve to improve the condition. Clinical Relevance. Scientific rationale for the study : Toothbrushing, especially power toothbrushing, was suspected to account for progressive gingival re