Early caries detection on smooth surfaces by QLF in children

Objective: This study is to explore the prevalence of very early caries on smooth surface in the maxillary anterior teeth in Chinese school children of Chengdu City using quantitative light-induced fluorescence (QLF). Methods: The total number of 9583 children of 11, 13, 14-year-old from 18 primary schools and 6 middle schools were examined. All the students brushed their teeth using no fluoride toothpastes at first. The plaque and calculus on the maxillary anterior teeth surfaces were eliminated by one examiner in daylight. Then these surfaces were dried for 30 seconds using air syringe. QLF images were taken in the dark room and saved in the PC hard drive for analyses. The difference of the prevalence was analyzed by SPSS software. Results: In QLF examination 3.58 percent of the examined children were found out having very early caries on the maxillary anterior teeth surfaces. Results of the Chi-square test showed that 11-year-old children had a higher prevalence of very early caries on the maxillary anterior teeth surfaces(3.94%) than that of 13-year-old children(2.59%) and P<0.01. However, there was no significant difference of the prevalence of very early caries in 11 and 14-year-old, neither had 13 and 14-year-old children. There was no significant difference of the prevalence by the sex among the three age groups. Conclusion: The study was suggested that although the prevalence of very early caries on smooth surface in the maxillary anterior teeth was not very high, oral health preventive programs still should be strengthened in primary schools and middle schools. In addition, QLF is a trustworthy, speedy, safe and noninvasive diagnosed method of very early caries and was worthy extending and applying in the examination.