Skip to main content

Table 2 Main results

From: In-office bacteria test for a microbial monitoring during the conventional and self-ligating orthodontic treatment

Plaque Index (PI) PI (T0) PI (T1) PI (T2) T0 versus T1 T0 versus T2 T1 versus T2
Self-ligating brackets group 0 23 28 W= 153.06 P=0.001 W= 97.53 P=0.001 NS
Conventional brackets group 0 33 37 ** W= 133.06 P=0.001 W= 178.0 P=0.001 NS
Control group 0 14 ** 27 W= 127.88 P=0.001 W= 188.0 P=0.001 NS
  Buffering capacity (indicated as the more frequent nominal value for each group) Self-ligating group VERSUS Control group Conventional group VERSUS Control group Self-ligating group VERSUS Cnventional group
Self-ligating brackets group 3 (middle boffering capacity)    NS
Conventional brackets group 4 (middle-high capacity) NS   
Control group 3 (middle capacity)   NS  
  Salivary Flow (T0) Salivary Flow (T1) Salivary Flow (T2) T0 versus T1 T0 versus T2 T1 versus T2
Self-ligating brackets group 59 69 69 W= 10.7 P=0.05 W= 97.53 P=0.001 NS
Conventional brackets group 51 59 59 NS NS NS
Control group 50 50 ** 50 * NS NS NS
  % of subjects with abnormal value (>10 5 ) T0 % of subjects with abnormal value (>10 5 ) T1 % of subjects with abnormal value (>10 5 ) T2 T0 versus T1 T0 versus T2 T1 versus T2
Self-ligating brackets group 0% 25% 45% NS Chi-square= 10.17 P= 0.01 NS
Conventional brackets group 0% 60% ** 20% ** Chi-square = 97.53 P=0.001 Chi-square= 24.47 P= 0.001 Chi-square= 88.6 P=0.001
Control group 0% 5% 35% NS Chi-square= 10.75 p=0.001 Chi-square= 14.25 P=0.01
  % of subjects with abnormal value (>10 5 ) T0 % of subjects with abnormal value (>10 5 ) T1 % of subjects with abnormal value (>10 5 ) T2 T0 versus T1 T0 versus T2 T1 versus T2
Self-ligating brackets group 0% 10% 25% Chi-square=5 P=0.03 Chi-square=4.27 P=0.04 Chi-square=27.22 P=0.001
Conventional brackets group 0% 50% 70% Chi-square=35.5 P=0.001 Chi-square=80 P=0.001 NS
Control group 0% 10% 30% NS Chi-square=8.8 P=0.001 Chi-square=8.8 P=0.001
  1. The total PI (Plaque Index) for each group, expressed as the sum of the individual scores for each group. Significant differences among the three groups were assessed with the Friedman test for each group and the Mann-Whithney U test to assess inter-group differences and Wilcoxon signed rank test (W) for intra-group differences. Buffering capacity of saliva, expressed as the more frequent evaluation in each group, recorded before the beginning of the study. Significant differences were assessed with Chi-square test comparing five categories (low, middle-low, middle, middle-high, and high). Salivary flow expressed as the sum of the single rates for each subject. Significant differences were assessed with Friedman test and the Mann–Whitney U test and the Wilcoxon signed rank test (W) for inter-groups and intra-group differences, respectively. Prevalence of subjects with abnormal values of microbial colonization calculated as percentage respect to the numerosity of each group.