Fluoride bioactive glass paste improves bond durability and remineralizes tooth structure prior to adhesive restoration

ObjectiveThe current study aimed at examining a fluoride containing bioactive glass (BiominF®) paste as a temporary filling material capable of remineralizing the demineralized enamel or dentin, and its ability to decrease a simulated dentinal fluids pressure on the resin/dentin interface, without affecting the shear bond strength of a universal bonding agent to enamel and dentin.Methods60 premolars were utilized for the acid resistance, trans-microradiography (TMR) and shear bond strength (SBS) experiments. Enamel and dentin discs were demineralized for 4 days to create a subsurface demineralized zone followed by applying BiominF® paste, 1.23% acidulated phosphate fluoride, or a temporary filling material for 24 h.30 extracted human non-carious third molars were utilized for the pulpal pressure experiment in which direct communication to the pulp chamber was created by cutting at a level approximately 1 mm below the cemento-enamel junction while the coronal enamel was ground to expose mid coronal dentin. The dentin surface was exposed to a simulated pulpal pressure. The dentin surfaces had BiominF® paste, an oxalate desensitizing agent, or temporary filling material followed by application of a universal adhesive system.ResultsOne way ANOVA showed that BiominF® paste remineralized effectively the demineralized enamel or dentin, did not affect the bond strength of the enamel and dentin surfaces to the tested adhesive system p < 0.05, and improved the acid resistance of the demineralized enamel and dentin against a secondary erosive challenge. Moreover, BiominF® paste decreased the nanoleakage expression in the dentin/adhesive interface exposed to a simulated pulpal pressure.SignificanceBiominF® paste may serve as a temporary filling material that may improve the longevity of adhesive restorations and help to conserve tooth structures by preserving the demineralized enamel and dentin form cutting during cavity preparation.     

釉质龋的非破坏性治疗方法

釉质龋是一种非细胞反应性病变,可导致牙齿硬组织的破坏.传统治疗釉质龋的方法往往会损害到正常的牙体组织,因此目前非破坏性修复釉质龋的新方法成为了研究的热点和难点,本文就非破坏性治疗釉质龋的2种方法——再矿化和仿生矿化法的最新进展作一综述.     

Effect of dentifrice containing fTCP,CPP-ACP and fluoride in the prevention of enamel demineralization

Objective: To evaluate the effect of different fluoride- and calcium- and/or phosphate-containing products on their ability to prevent enamel demineralization under pH cycling conditions.

Material and methods: Enamel bovine specimens were assigned to the following groups: G1-MPP (MI Paste Plus, 0.2% NaF, Recaldent?, GC Corporation Tokyo, Japan); G2-FD (Crest? Cavity Protection, 0.243% NaF, Procter &; Gamble, USA); G3-CLP (Clinpro? 5000, 1.1% NaF, 3M ESPE, USA); and G4-CO (Control without fluoride, Silica-based dentifrice; Daudt Ltda, Brazil). The specimens were soaked in demineralizing solution for 6?h and remineralizing solution for 18?h alternatively for 10 days. The toothpaste was prepared with deionized water in a 1:3 ratio (w/v) for three minutes daily. The solutions were renewed every 48?h. After cycling, enamel changes were analysed by percentage change of SMH (%SMH) and energy-dispersive X-ray spectroscopy (EDS). The %SMH value observed for G3-CLP (2.9?±?39.2) was higher than that found in G4-CO (?13.0?±?20.7), G1-MPP (?8.9?±?20.9) and G2-FD (?3.9?±?27.1). The %SMH was similar for all treatment groups (one-way ANOVA and Tukey’s HSD; p?2+ and P_total in the remineralization solutions were not different among all groups (Kruskal–Wallis; p?2+ concentration in the demineralization solution was significantly lower in G1-MPP. Ca²⁺ concentration increased in all groups after 48?h, except for G3-CLP. The EDX quantitative analysis showed that the atomic % of elements is lower level at G4-CO.

Conclusions: The Clinpro? 5000 demonstrated having the most protective effect against demineralization; however, the % SMH was similar for all groups.     

Enamel remineralization effect of a dentifrice containing calcium sodium phosphosilicate: an optical coherence tomography observation

Objective: The purpose of this study was to examine the effects of a dentifrice containing 5% calcium sodium phosphosilicate (CSP) on the remineralization of the enamel using optical coherence tomography (OCT).

Materials and methods: Bovine incisors were sliced and shaped in a rectangular form. One group of five specimens was treated with undersaturated 0.1 M lactic acid buffer solution (pH 4.75) for 10?min and then placed in artificial saliva (pH 7.0) (De group). Other specimens were stored in solutions of toothpaste containing CSP for 10?min, followed by 10-min immersion in the lactic acid buffer solution twice a day before storage in artificial saliva (CSP group). An additional group was stored in only artificial saliva (control group). OCT imaging on the selected location of the enamel surface was performed. The peak intensity and width at 1/e² were recorded in each of the six areas on the sample and averaged, and the sample size of each group was six. The integrated value in units (dB?×?μm) was calculated in the area of peak intensity. The data for each group was subjected to one-way repeated-measures ANOVA and Tukey HSD tests (α?=?0.05).

Results: The changes in integrated values of each group were different. A slight but significant increase in the integrated value was observed in the control group, whereas a slight but significant decrease in the value was observed the De group. Integrated values increased in the CSP group.

Conclusions: Remineralization occurred upon immersion in the toothpaste containing CSP.     

釉基质蛋白对人牙髓细胞成牙本质分化的影响

目的 探讨釉基质蛋白对人牙髓细胞(human dental pulp cells,HDPC)成牙本质分化的影响,为牙本质的组织工程学研究提供有效的生物活性物质.方法 将HDPC接种于6孔板(2×105个/孔)后分为5组,分别加入含1、10、100 mg/L釉基质蛋白(enamel matrix proteins,EMP)(分别为EMP 1、10、100 mg/L组)、10-8 mol/L地塞米松及100 mg/L抗坏血酸(dexamethasone and ascorbic acid,Dex-AA组)、单纯基础培养液(对照组).于培养1、5、10 d分别用碱性磷酸酶(alkaline phosphatase,ALP)试剂盒检测ALP活性,实时荧光定量反转录聚合酶链反应技术检测成牙本质相关基因牙本质基质蛋白1(dentine matrix protein-1,DMP-1)及牙本质涎磷蛋白(dentine sialophosphoprotein,DSPP)的表达,应用2-△△CT方法得出具体数值并进行单因素方差分析与Post Hoe 检验,用茜素红染色检测并定量分析矿化情况.结果 各组ALP水平呈时间依赖性上调,培养1d后各组ALP活性与对照组相比差异均无统计学意义;5 d后EMP 10、100 mg/L组及Dex-AA组ALP活性显著增高,分别达到7.573±0.267、6.119±0.502、5.846±0.096,与对照组相比差异均有统计学意义(P＜0.05);10 d后10 mg/L EMP组及Dex-AA组ALP活性增高更显著,分别达21.035±0.149、13.223±0.797,与对照组(5.825±0.404)相比差异均有统计学意义(P＜0.01).培养1d后各组DMP-1及DSPP mRNA水平均较对照组显著升高,差异均有统计学意义(P＜0.01);培养10 d后10 mg/L EMP组DMP-1和DSPP表达水平均显著增高,分别达到14.791±0.164、12.238±0.421.培养10 d后各组均有矿化,10 mg/L EMP组钙离子浓度[(191.8±2.0) μmol/L]显著高于对照组[(81.1±8.1)μmol/L],差异有统计学意义(P＜0.01).结论 适当浓度的EMP对HDPC的成牙本质分化有一定的促进作用.     

正常唾液及氟化物对脱矿年轻恒牙牙釉质的再矿化作用

目的:用显微硬度测量法研究正常人体唾液及氟化物对碳酸饮料酸蚀的年轻恒牙牙釉质的再矿化作用。方法:收集口腔正畸门诊减数拔牙所拔除的新鲜、健康年轻恒牙23颗,制成牙釉质样本90块,随机分为对照A组、实验B组及实验C组;每组又分为三个亚组(A1、A2、A3、B1、B2、B3、C1、C2、C3),其中A1、B1、C1浸泡在雪碧中1周、A2、B2、C2浸泡在芬达中1周、A3、B3、C3浸在百事可乐中1周,每组10个牙块。A组牙浸泡完后直接用显微硬度仪做表面硬度测试;B组牙用蒸馏水冲洗干净后分别浸泡于装有正常人体唾液的容器中,将容器置于37℃恒温箱中,定期摇动容器,1月后取出用显微硬度仪做表面硬度测试;C组牙则用蒸馏水冲洗干净后,每日早中晚3次用含氟牙膏涂布牙齿开窗处表面10 min,再分别放入装有正常人体唾液的容器中,将容器置于37℃恒温箱中,定期摇动容器,1月后取出用显微硬度仪做表面硬度测试。结果:正常人体唾液及氟化物均能使脱矿后年轻恒牙牙釉质表面硬度明显升高(P<0.05),且两者之间有统计学差异(P<0.05)。结论:正常人体唾液及氟化物对脱矿年轻恒牙的再矿化作用明显。     

Comparison of quantitative light-induced fluorescence, digital photography and transverse microradiography for quantification of enamel remineralization

Background: Quantitative light‐induced fluorescence (QLF) and digital photography (DP) have been proposed as clinical methods for measuring changes in enamel mineral content. The aim of this study was to compare the ability of QLF and DP with the in vitro gold standard transverse microradiography (TMR) to measure the remineralization of enamel subsurface lesions. Methods: Subsurface lesions were formed in enamel (n = 40) and exposed to remineralization solutions for 10 days. Changes were analysed by DP, QLF and TMR to determine percentage changes in luminescence (%L), fluorescence (%F) and mineral content (%R), respectively and correlation between these parameters determined. Results: The correlations between TMR and QLF (r = 0.63), TMR and DP (r = 0.59), and DP and QLF (r = 0.64) were all moderate but statistically significant (p < 0.001). The variability in %L and, to a lesser extent, %F values significantly impacted on the potential role of DP and QLF as methods by which mineral content changes produced by remineralization treatments could be accurately measured. Conclusions: Both QLF and DP provided data that correlated moderately with TMR data. QLF images were easier to analyse, free of glare and had less variability compared with those produced using DP.     

茶多酚对早期龋进展的影响

目的　探讨茶多酚对牙齿早期龋进展的影响。方法　采用体外脱矿的方法建立牛牙牙釉质和牙本质早期龋模型。将釉质龋及牙本质龋标本随机分为4组（n=6）：空白对照组（DW组）、氟化钠组（NaF组）、茶多酚组（TP组）、茶多酚与氟化钠联合应用组（TP+NaF组）,pH循环实验模拟早期龋的进程。检测pH循环后的脱矿液中钙、磷离子浓度,通过显微硬度计检测牙体硬组织表面显微硬度值,X线能谱分析样本表面钙磷比,并测定再矿化液中羟脯氨酸水平。结果　在牙釉质及牙本质的脱矿液中,TP组钙、磷离子相对释放量与DW组差异无统计学意义,明显高于NaF组和TP+NaF组（P＜0.05）。TP组牙釉质表面显微硬度值与DW组差异无统计学意义,牙本质表面显微硬度值高于DW组;DW组、TP组牙釉质及牙本质表面显微硬度值均低于NaF组和TP+NaF组（P＜0.05）。TP组牙釉质及牙本质表面钙磷比均高于DW组（P＜0.05）,牙釉质表面钙磷比与NaF组和TP+NaF组差异无统计学意义,牙本质表面钙磷比低于NaF组和TP+NaF组（P＜0.05）。NaF组和TP+NaF组牙本质再矿化液中羟脯氨酸水平均低于DW组和TP组（P＜0.05）,TP组与DW组以及TP+NaF组与NaF组间差异均无统计学意义。结论　在早期龋的进展过程中,茶多酚无明显抑制牙釉质及牙本质脱矿的作用,但可通过促进钙磷离子的再沉积促进再矿化的发生。