Statistical analysis
PD, tooth
REGRESSION
Mean values and standard deviations were used to describe continuous variables. For categorical variables frequencies and percentages were used. Quantitative variables such as PD and CAL were sectioned into three distinct groups: 0–3 mm [For continuous variables at patient level, two-group t-test was used to test statistical differences, while chi-square tests were used for the categorical variables. Continuous variables were analysed using linear regression models reporting beta coefficients with 95% confidence intervals (95% CI). The categorical (dichotomous) outcome variables were analysed using logistic regression models, reporting odds ratios (ORs) with 95% CI. For tooth and site-specific outcomes variables, the regression analyses were performed using cluster robust variance estimates to adjust for multiple measures per individual. Stata version 17 (TX, USA) was used for the statistical analyses. P-values less than 0.05 were considered statistically significant.