Dental caries and first permanent molar pit and fissure morphology in 7-to 8-year-old children in Wuhan,China

To obtain the caries experience and, plaque accumulation severity and pit and fissure morphology in first permanent molars in 7-8 children in Wuhan, as a reasonable prediction of caries risk and preventive attention in the future, a convenient sample of five primary schools in the vicinity of the Wuhan University School and Hospital of Stomatology was drawn. Two calibrated examiners orally examined all present grade 2 children in the classroom, using standard caries plaque and tooth morphology criteria. Dental caries was scored at enamel （D2） and dentine （D3） for tooth and surface level. Independent variables were age, gender and school. Data analysis used analysis of variance and t-test. The sample comprised 1 043 7- and 8-year-olds. The prevalence of dental caries in permanent dentition was 8.7% and in primary dentition, 68.7%. Mean Decayed, Missing, Filled Teeth/S （DMFT/S） scores were 0.1 1 and . 14, respectively. Mean dmft/s scores were 2.8 and 5.0. The d-component constituted 75% of the d3mft index, while enamel carious lesions constituted 36% of the total number of carious lesions （d2,3-component）. Prevalence of medium and deep pits and fissures was 84.6%. Prevalence of medium and severe plaque accumulation was 67.4%. Prevalence of dental caries in the deciduous and permanent dentitions of 7- to 8-year-old children was high. Deed oits and fissures in high caries risk children should be sealed_

Evaluation of Ion Release from Four Dental Sealants

The purpose of this study was to determine the ion release from four commercially available pit-and-fissure sealants [3M Clinpro, 3M ConciseTM, BeautiSealant （BS）, and GI FX-Ⅱ）]. With each brand, 18 specimens were prepared. Their fluoride release in de-ionized water was measured by fluoride electrode, while the release of silicate （Si）, aluminum （A1）, sodium （Na）, calcium （Ca）, strontium （Sr）, and phosphorus （P） was measured by inductively coupled plasma atomic emission spectroscopy （ICP-AES） on days 1, 3, 7, 14, 21, and 28. The result showed that fluoride was not released from 3M ConciseTM. GI FX-II displayed the largest fluoride release, which, however, dropped rapidly on day 3.3M Clinpro exhibited less fluoride release than GI FX-II and BS did. At any time during the 28-day experimental period, GI FX-II released more Na than the other sealants （P〈0.001）. BS ranked the second in Na release, and a small amount of Na ions was released from the 3M Clinpro and 3M ConciseTM samples. Al ions were only detected from BS and GI FX-Ⅱ, but not from the 3M Clinpro and 3M ConciseTM. Additionally GI FX-II had the largest Si release among the four brands at any time during the experimental period （P〈0.001）. Ca ions were detected from 3M Clinpro and 3M ConciseTM, but not from GI FX-Ⅱ. BS released more Sr than the other sealants at any time during the experimental period （P〈0.001）. All the samples released similar amounts of P continuously during these 28 days. In conclusion, based on the type and the amount of ion release, BS is the best pit-and-fissure sealant among the four brands.