五倍子原液和中性液促进牙釉质人工龋再矿化作用的比较

目的 比较五倍子原液、中性液促进牙釉质人工龋的再矿化作用,探讨五倍子药液pH调节对其促进釉质龋再矿化作用的影响.方法 制备牛牙釉质人工龋标本,配制五倍子多酚化合物原液(pH 3.8)和五倍子多酚化合物中性液(pH 7.0).体外pH循环条件下分别使用NaF(NaF组)、去离子水(去离子水组)、五倍子多酚化合物原液(pH 3.8五倍子组)及中性液(pH 7.0五倍子组)处理龋标本.原子力显微镜下观察pH循环前、后各组标本再矿化层的形貌特点.显微放射照相检测pH循环前后标本的矿物丢失量及龋损深度.结果 pH循环后,原子力显微镜下两个五倍子组牙釉质表面均有明显的不规则突起物,在不规则排列、边界模糊的晶体表面散在分布了大量的颗粒.显微照相检测到NaF组、去离子水组、pH 3.8五倍子组、pH 7.0五倍子组样本的矿物丢失量变化百分率分别为(-38±14)%、(+43±7)%、(-10±4)%和(-11±4)%;龋损深度变化百分率分别为(-27.79±3.51)%、(+21.13±2.83)%、(-8.43±3.32)%和(-9.20±3.89)%,两个五倍子组均表现出整体矿物丢失和龋损深度减小,两组间整体矿物丢失量变化百分率和龋损深度变化百分率差异无统计学意义(P＞0.05).结论 五倍子原液与中性液促进早期釉质龋的再矿化作用无明显差异,五倍子药液pH调节对其促进再矿化作用无明显影响,用药过程中无需将瓦倍子原液调节至中性.

Abstract：

Objective To compare the effect of original and neutral G alla chinensis in promoting the remineralization of initial enamel carious lesions in vitro and to investigate the influence of Galla chinensiswith different pH on the promoting effect. Methods Bovine sound enamel slabs were demineralized to produce initial carious lesion in vitro. Then the lesions were exposed to a pH-cycling regime for 12 days.Each daily cycle included 4 × 1 min application of one of four treatments: distilled and deionized water (DDW), aqueous solutions of NaF, acidic or neutral aqueous solutions of Galla chinensis extract(GCE). Before and after pH-cycling, the surface topography of the enamel slabs was observed by atomic force microscopy( AFM), and the integrated mineral loss and lesion depth of all the specimens were analysed by transverse mieroradiography. Results AFM images revealed the surface topographical changes of GCE- treated enamel. The percentage change of integrated mineral loss ( △IML% ) of the samples of NaF group,DDW group, pH 3.8 GCE group and pH 7.0 GCE group was ( -38 ± 14)%, ( + 43 ± 7 )%, ( - 10 ± 4)% and ( - 11 ± 4)% respectively. The percentage of lesion depth (△LD%) of the samples of NaF group,DDW group, pH 3.8 GCE group and pH 7.0 GCE group was( -27.79 ±3.51 )%, ( +21.13 ±2. 83)%,( -8.43 ± 3.32)% and ( -9.20 ± 3.89)% respectively. There was no significant difference in △IML%and △LD% between pH 3. 8 and pH 7. 0 GCE-treated enamel. Conclusions There is no significant difference in enhancement of remineralization of initial enamel carious lesions between the original and neutral Galla chinensis. Different pH Galla chinensis does not have obvious influence on remineralization. It is unnecessary to regulate the pH value of queous solution of Galla chinensis extract which acts as a anticaries agent.     

Cost‐effectiveness of an experimental caries‐control regimen in a 3.4‐yr randomized clinical trial among 11–12‐yr‐old Finnish schoolchildren

The aim of this study was to assess the cost‐effectiveness of an experimental caries‐control regimen in a randomized clinical trial (RCT) conducted in Pori, Finland, in 2001–2005. Children (n = 497) who were 11–12 yr of age and had at least one active initial caries lesion at baseline were studied. The children in the experimental group (n = 250) were offered an individually designed patient‐centered regimen for caries control. The children in the control group (n = 247) received standard dental care. Furthermore, the whole population was exposed to continuous community‐level oral health promotion. Individual costs of treatment procedures and outcomes (DMFS increment score) for the follow‐up period of 3.4 yr were calculated for each child in both groups. The incremental cost‐effectiveness ratio was €34.07 per averted DMF surface. The experimental regimen was more effective, and also more costly. However, the total costs decreased year after year, and for the last 2 yr the experimental regimen was less expensive than the standard dental care. The experimental regimen would probably have been more cost‐effective than standard dental care if the follow‐up period had been longer, the regimen less comprehensive, and/or if dental nurses had conducted the preventive procedures.     

Quantification and gene expression of Lactobacillus casei group species associated with dentinal lesions in early childhood caries

BackgroundConsidering that the Lactobacillus casei group is strongly associated with caries progression, the use of lactobacilli as probiotics must be balanced due to their possible involvement in dental caries.ObjectiveThis study aimed to detect and quantify L. paracasei, L. rhamnosus, and L. casei group species in the active and arrested dentinal lesions of preschoolers. It also aimed to determine the expression profiles of lactobacilli genes related to adhesion, extracellular polymeric substance regulation, and pyruvate oxidation.MethodsTotal ribonucleic acid (RNA) was extracted from dentinal lesion samples (25 active, 13 arrested) of children between 2 and 5 years of age. The samples were converted to complementary deoxyribonucleic acid (cDNA), and quantitative polymerase chain reaction (qPCR) analyses were performed to quantify and determine the relative abundance (measured by percentage of total bacteria) of L. paracasei, L. rhamnosus, and L. casei group species. The expression profiles of L. paracasei/casei genes (spaC and spxB) and L. rhamnosus genes (spaE and wzb) were assessed. The Student t-test and the Mann-Whitney U test were used for comparisons.ResultsThe L. casei group species were found to be part of the viable microbial community in dentinal caries. L. paracasei (p = 0.001), L. rhamnosus (p = 0.022), and L. casei (p = 0.004) group species were abundant in the active dentinal lesions compared to the arrested dentinal lesions. Only the wzb gene (p = 0.006) exhibited a statistically significant difference between the active and arrested lesions in terms of its expression profile; it was expressed to a higher extent in the active dentinal lesions.ConclusionsThe L. casei group species presented in large numbers in the active dentinal caries lesions, indicating that these microorganisms are related to caries activity, and the wzb gene may play an important role in caries progression.