Statistical analysis Age, FPG, HbA1C, tooth, and sounding depth were presented in means and standard deviation. The intra-group differences were calculated with Wilcoxon rank test. The inter-group differences were calculated with Mann-Whitney test. Sex, bacterial plaque, and bleed to the sounding were summarized using proportions and analyzed with the chi-square method. In all analyses, a P-value of <0.05 (two tailed) was considered statistically significant. All statistical analyses were conducted using SPSS software (IBM Corporation, Armonk, NY, USA) version 21.