This study investigated the prevalence and severity of gingivitis and plaque in a representative Chinese population of adults.
Methods: Using the Loe-Silness gingivitis index (GI) and the modified Quigley-Hein plaque index (PULI), researchers examined 1143 patients from Guangzhou, Shenyang, and Nanjing for the presence of gingivitis and plaque. A two-tailed t-test was used to determine significant differences in the GI and PLI scores between gender and urban/rural areas. The data pertaining to study sites and age groups were compared using the Kruskal-Wallis one-way analysis of variances (ANOVA) by ranks. The correlation between GI/PLI and age was examined using the Pearson correlation coefficient. Age differences among three sites were analyzed with the one-way ANOVA.
Results: The age and urban/rural compositions (mean age 42.2 years) paralleled the 2008 China census. The overall average and standard deviation of GI and PLI were 1.101 +/- 0.239 and 3.394 +/- 0.578, respectively. Age significantly correlated with GI and PLI (P < .0001). The PLI in males was significantly higher (P < .0001) than in females; however, no significant difference was noted between GI in males compared to females. Patients in rural areas showed a significantly higher GI and PLI (t = 7.723, P < .0001; t = 7.072, P < .0001) than those in urban ones.
Conclusions: Clinical trials evaluating a product's antigingivitis efficacy should recruit participants from a population that represents accurately the intended product users. Variables should include gender, race, age, and geography.