Abstract
Two kinds of sewing needles (Sokyu), No. 1 (Diameter 1.14 mm) and No. 4 (Diameter 0.89mm), were used to examine the dental caries of 295 children in elementary schools. Caries was detected at occlusal pits and fissures of permanent molars (including buccal surface pits of 1st and 2nd molars) and at lingual pits of permanent anterior teeth, and cavity detection rates were calculated. Cavity detection rate by No. 4 needle was higher than by No. 1 needle, and No. 4 needle detected 1.7 to 2.5 times more cavities than No. 1 needle in each school grade. There were statistically significant differences at a probability of less than 0.001 in each school grade.
