2. Materials and Methods
caries
BLIND, CARIES
This study was conducted in a southern Thai province and included 15 eligible sub-district health promoting hospitals (SHPHs) in rural areas that performed dental sealants in schools. The study design was a single blind (outcome assessors) cluster randomized control trial and parallel group study with balanced randomization (1:1). The clusters were SHPHs that included groups of dental nurses who implemented school dental sealant programs. The cluster study was designed because the children were treated by responsible dental nurses in each SHPH. The children included according to the criteria: at least one caries-free lower first permanent molar with deep pits and fissures, and good cooperation. The sealant material used in this study was ConciseThe outcome as an indicator of school sealant quality was the presence of caries on the sealed surfaces. The outcome was assessed at 15–18 months after sealing. After the start of the study, the results and methods were changed from 6 and 12 months to 15–18 months due to the COVID-19 pandemic situation. The evidence of caries or the final outcome was discoloration of the occlusal surface and sticking with gentle probing according to Simonsen criteria [Data analysis was performed using the program R, version 4.2.1 (R Development Core Team, Vienna, Austria) [