GSTM1 and periodontal disorder: People who had information about the effect of periodontal disease on diabetes had the highest Hb A1c <7% (p= 0.032).The most recent Hb A1c <7% was higher in people who brushed their teeth twice a day or more, as well as those who used dental floss oncea day or more (p< 0.001 and p= 0.014 respectively)(Table 2).