This study aimed at evaluating the effectiveness and feasibility of adding cavity fillings for the first permanent molars to the Comprehensive Intervention Project of Oral Diseases in school-age children.

A total of 411 children aged from 7 to 9 (208 in the control group and 203 in the experimental group) from Daqing Road Primary School in Xiangyang City, Hubei Province were recruited by cluster random sampling as the research subjects in class units. At baseline, all children recruited received prevention practice including oral health education, oral examination, and pit and fissure sealants for the non-cavitied fully-erupted first permanent molars. For the cavitied lesions, cavity fillings were provided to the experimental group, while only treatment advice was provided to the control group. At the follow-up for 2 years, the caries prevalence and caries filling ratio of the first permanent molars were compared between the two groups. In addition, all teeth were divided into two groups (the treated group and the non-treated group) according to whether they were treated or not, and the risk of caries in the two groups was compared. Chi-square test and t-test were used to compare the difference in caries rate between the control and experimental groups. The risk of caries was compared between the treated group and non-treated groups by calculating RR and 95% CI.

A total of 408 children (206 in the control group and 202 in the experimental group) completed this study. At 2 years, the prevalence rate of dental caries in the experimental group was 11.9%, lower than that in the control group (22.3%) , with statistically significant difference (χ² = 7.712, P = 0.006) . The filling ratio of the experimental group (64.2%) was higher than that of the control group (22.5%) , and the difference was statistically significant (χ² = 32.485, P<0.001) . The non-treated group had a higher risk of new caries (RR for teeth = 6.52, 95% CI = 3.51-12.09; RR for surfaces = 9.98, 95% CI = 5.86-17.00) compared with the treated group.

As the cavity fillings could effectively control the occurrence and development of caries, it is feasible and effective to incorporate cavity fillings into public oral health program.