渗透树脂治疗早期龋的研究新进展

早期龋的发生是牙釉质脱矿与再矿化交替进行的动态过程,阻止脱矿的进展是治疗早期龋的关键。渗透树脂作为一种新型材料,具有粘性低,表面张力小的特点,可进入龋损的微小孔隙并堵塞封闭形成屏障,阻止龋损的进展。树脂渗透技术是近年来治疗早期龋的新技术,具有微创,无痛的优点,易于被患者接受。近年来国内外学者针对渗透树脂的渗透原理、临床效果做了大量研究,该文将对上述研究进展进行综述。     

树脂渗透技术治疗早期釉质脱矿的研究进展

早期釉质脱矿是龋病防治的有效阶段,传统的治疗方法主要包括药物治疗和修复治疗。树脂渗透技术是一种采用特殊低黏度树脂渗透到早期龋齿多孔病变体层中的微创技术,为早期釉质脱矿的治疗提供了新的选择。相较于传统的治疗方法,树脂渗透治疗无痛、微创、对患者依从性要求低,远期疗效好。文章就树脂渗透技术的原理、优势、适应证以及与其他牙科材料的联合应用做一综述。     

乳牙釉质发育缺陷与儿童早期龋相关研究

釉质发育缺陷是一种临床常见疾病,是由成釉器的损伤引起的牙釉质质量和数量的异常。该疾病在乳牙及恒牙中均可发生,乳牙的釉质发育缺陷常导致儿童早期龋的发生,因此受到更多儿童口腔科医生的关注。本文汇总了近15年有关于乳牙釉质发育缺陷与儿童早期龋相关性内容的中英文文献,从乳牙釉质发育缺陷的诊断、导致儿童早期龋发生的原因、治疗方法以及预防措施等方面进行综述。     

ICON渗透树脂修复人工釉质龋白斑的效果研究

目的：评价ICON渗透树脂修复人工釉质龋白斑的效果。方法：选取因正畸而拔除的前磨牙28颗,制备人工釉质龋后,随机分为实验组和对照组,实验组采用ICON渗透树脂修复人工釉质龋白斑,对照组采用涂氟处理,测量并比较釉质龋白斑修复后的表面微硬度和龋白斑面积减少百分比,最后采用SPSS17．0软件进行统计分析。结果：治疗修复后实验组釉质龋的表面微硬度值显著高于对照组,差异具有统计学意义（P＜0．05）;修复后实验组龋白斑所占面积百分比低于对照组,差异具有统计学意义（P＜0．05）。结论：ICON渗透树脂能提高人工釉质龋白斑表面的微硬度,并能大大降低龋白斑的面积百分比,推荐临床使用。     

护牙素对放射线照射下牙釉质显微硬度的影响

目的:探讨护牙素对放射线照射下釉质脱矿与再矿化的影响。方法:挑选佛山市第一人民医院医院口腔医学中心因正畸减数拔除的上颌第一前磨牙40颗,分开颊舌两侧,制成80个釉质块,随机分为A、B、C、D组,采用Co-60放疗仪在20℃对每个釉质表面进行放射线照射。A组为单纯照射组,直接采用放射线照射开窗区;B组为涂膜照射组,照射前先在开窗区涂上护牙素,再进行放射线照射,照射结束后去离子水冲洗釉质面;C组为照射后再矿化组,放射线照射开窗区6周后再应用护牙素,30min/d,持续4周;D组为对照组,只在相同环境中保存,开窗区表面不做任何处理。处理前后分别测量各组的显微硬度值。采用SPSS16.0统计软件进行数据分析。结果:4组样本按照相应的处理方式处理后,测量结果显示单纯照射组的牙釉质表面HV明显低于其它3组(P<0.05),而涂膜照射组和照射后再矿化组的HV与对照组没有显著差异。结论:应用护牙素能够有效地预防放射线所致的釉质脱矿,并能促进釉质再矿化。     

渗透树脂治疗早期龋的研究进展

渗透治疗是一种新兴、微创的早期龋治疗方法,主要通过渗透树脂与脱矿釉质晶体结合,阻断釉质内部进一步脱矿并对病损结构进行增强,进而遏制龋病发展。与传统树脂充填治疗相比,具有无需钻磨、最大程度保留牙体组织、无痛、一次完成治疗、经济成本低等优点。本文就渗透树脂的体系形成、性能评价及成分改进进行综述。     

乳牙釉质混浊的偏光特点及其与龋齿易感性的研究

目的 从临床和实验研究两方面探讨乳牙釉质混浊对龋齿的易感性。方法 选择176名3-8岁的低出生体重儿和早产儿，分析乳牙釉质混浊与龋齿的相关性；将5颗自然脱落的釉质混浊乳前牙用于偏光显微镜的研究，发现其组织学特点，并探讨乳牙釉质混浊的发生机制。结果 临床研究发现乳牙釉质混浊与龋齿的发生显著相关；进一步的偏光显微镜研究的发现乳牙釉质混浊为表层下矿化缺陷，且矿化缺陷区域釉柱横纹加重。结论 乳牙釉质混浊因其表层下矿化缺陷增加了牙齿对龋的易感性，乳牙釉质混浊其发生为在牙齿矿化阶段的第三矿化期的中晚期出现全身或局紊乱所致。     

渗透树脂和多乐氟处理脱矿釉质后的抗酸性和再矿化能力比较

目的 通过观察渗透树脂与多乐氟处理脱矿釉质后其牙齿表面显微硬度和粗糙度的变化,对两种材料在釉质抗酸性和再矿化能力方面的性能进行评估。方法 选择正畸拔除的健康前磨牙48颗,建立釉质表面脱矿模型,按照不同材料的处理条件随机分为4组,A（不做任何处理）,B（渗透树脂）,C（多乐氟）;D（渗透树脂+多乐氟）,分别经脱矿液组（1d,3d）和再矿化液组（7d）浸泡处理后,测定牙齿表面的显微硬度和粗糙度。结果 不同材料处理脱矿模型后即刻,B、D组的显微硬度、粗糙度均明显增加（P<0.001）,B、D组之间无统计学差异（P>0.05）;而C组显微硬度、粗糙度均明显减低（P<0.001）。继续脱矿（1d,3d）后,各组的显微硬度均下降,而粗糙度却明显增加;再矿化7d后,A、C组显微硬度和粗糙度均显著增加（P<0.001）,B、D组增加不明显（P>0.05）。结论 渗透树脂具有良好的改善牙齿表面硬度的作用,但在抗酸性和促进牙齿再矿化方面无明显优势。而氟化物则在抗酸性和促进再矿化方面有突出表现。当两者联合应用时,可以起到较好协同作用,明显增强牙齿的硬度、抗酸性和再矿化性能。     

Surface conditioning of natural enamel caries lesions in deciduous teeth in preparation for resin infiltration

Objectives

As a conditioning step for resin infiltration into caries lesions, the relatively impermeable surface layer should be removed using hydrochloric acid gel (15%) to achieve improved infiltration, as it could be shown for permanent teeth. It is unclear whether this etching regimen can be transferred to the deciduous dentition, where differences in surface structure have been reported. Thus, the aim of the present study was to evaluate the effect of phosphoric and hydrochloric acid gels on the surface layer reduction of natural lesions of primary teeth.

Methods

Thirty-two extracted or exfoliated primary molars with lesions confined to enamel were selected. Paired lesion halves were partially etched with either 37% phosphoric (H₃PO₄) or 15% hydrochloric acid gel (HCl) for 30 s, 60 s, 90 s, or 120 s, respectively.

Results

Etching with H₃PO₄ resulted in incomplete reduction of the surface layers in all groups [highest percentage reduction (SD) at 120 s: 54 (28)%] as observed with confocal microscopy. In contrast, surface layers could be eroded almost completely [99 (3)%] by etching with HCl for 120 s.

Conclusion

An effective erosion of the surface layer of natural enamel caries in deciduous teeth can be achieved by etching with 15% hydrochloric acid gel for 90–120 s.     

运用色度学分析技术对离体乳牙脱矿与再矿化时间的实验研究

目的运用数码照相和色度分析技术观测不同酸蚀时间对离体乳牙釉质脱矿以及再矿化时间的影响,以寻找乳牙合适的脱矿及再矿化时间。方法将60颗离体上颌乳中切牙牙冠唇面开窗包埋。标本随机分为4个处理组,32%的磷酸凝胶分别酸蚀开窗面15s(组1)、30s(组2)、45s(组3)和60s(组4),使开窗面脱矿,再将其置于人工唾液中分别再矿化8h、24h、48h、72h及1周。脱矿后采用2%亚甲基蓝对开窗面进行染色,数码照相,运用图像分析软件对图像进行色度分析,记录色度参数,运用SPSS19.0对实验数据进行统计学分析。结果酸蚀15s后染色,其色度值变化即可被计算机所识别;酸蚀15s再矿化72h、酸蚀30s再矿化48h、酸蚀45s和60s再矿化24h时的色度值与矿化前的色度值相比,差异具有统计学意义,其P值分别为0.01、0.037、0.047和0.011。结论运用色度学技术分析乳牙脱矿与再矿化的时间,提示乳牙釉质最合适的酸蚀时间为15s,再矿化时间为72h。     

Micro-hardness and mineral loss of enamel lesions after infiltration with various resins: Influence of infiltrant composition and application frequency in vitro

Objectives

The aim of this in vitro study was to evaluate the influence of infiltrant composition and application frequency on micro-hardness and lesion progression after resin infiltration of artificial enamel lesions.

Methods

In each of 100 bovine enamel samples, three artificial caries lesions were created (pH = 4.95, 50 days). After etching two of the lesions (37% phosphoric acid) specimens were randomly allocated to five infiltrants (four experimental infiltrants with different monomer and solvent compositions and penetration coefficients, and one commercial infiltrant [Icon, DMG]). Lesions were then infiltrated and light-cured, and infiltration repeated afterwards for one of the lesions. Infiltrated samples were cut into halves, with one half being demineralised for further 50 days. Micro-hardness (VHN) and integrated mineral loss (ΔZ) were evaluated at baseline and after second demineralisation. Repeated measures ANOVA and paired t-tests were used to analyse influence of material composition and application frequency on micro-hardness and lesion progression (integrated mineral loss difference ΔΔZ).

Results

Resin infiltration significantly increased micro-hardness and reduced lesion progression compared to untreated artificial lesions (p < 0.05, t-test). Neither micro-hardness nor lesion progression were significantly influenced by material composition (p > 0.05, ANOVA). In contrast, twice application resulted in significantly increased micro-hardness and demineralisation resistance of infiltrated lesions (p < 0.05, ANOVA).

Conclusion

Resin infiltration significantly improves micro-hardness and demineralisation resistance of enamel lesions; these effects are significantly enhanced if resins are applied twice. Experimental resins did not outperform the commercial infiltrant.

Clinical significance

This in vitro study demonstrated that resin infiltration significantly increases both micro-hardness and demineralisation resistance of enamel caries lesions. Twice application of the infiltrant seems to increase these effects. In contrast, the composition of the infiltrant had no significant influence on investigated parameters.     

Response of pulp cells to resin infiltration of enamel white spot-like lesions

ObjectivesTo investigate the trans-enamel and trans-dentinal biological effects of treating enamel white spot-like lesions (EWSLs) with resin infiltration components (RICs) on odontoblast-like cells (MDPC-23) and human dental pulp cells (HDPCs).MethodsEWSLs were induced in 60 enamel/dentin discs (4.0 ± 0.2 mm thick) using S. mutans. The discs were adapted into artificial pulp chambers and MDPC-23 were seeded on the dentin surface. The components of a resin infiltration system (Icon) were applied individually or in combination on the enamel surface as following (n = 10/treatment): Etch, Infiltrant, Etch+Infiltrant, or Etch+Dry+Infiltrant. The application of water or hydrogen peroxide served as negative and positive controls, respectively. After 72 h, MDPC-23 viability was evaluated. The extracts were exposed for 72 h to pre-cultured MDPC-23 and HDPCs in 96-well plates to evaluate cell viability, alkaline phosphatase activity (ALP), mineralized nodule formation (MN), and the expression of inflammatory cytokines (ICs) and mineralization-related genes (MRs). Data were analyzed by ANOVA complemented with Tukey or Games-Howell post-hocs (α = 5%).ResultsCell viability, ALP activity, and MN formation were significantly reduced in response to the RICs, presenting intermediate values compared to positive and negative controls. Likewise, ICs were upregulated, whereas MRs were downregulated. Among the RICs, the Etch component caused the most notorious detrimental effects.SignificanceResin infiltration of EWSLs negatively affected the metabolism of pulp cells in vitro. Therefore, even though resin infiltration is a micro-invasive therapy for non-cavitated caries in enamel, it should be closely followed up seen that components may diffuse and unbalance pulp homeostasis.     

乳牙牙菌斑脂肪酸的分析研究

目的 了解乳牙菌斑中脂肪酸组成、含量及其与龋病的关系。方法 43名4-6岁幼儿按龋蚀状况分组，气相色谱-质谱联用技术、气相色谱技术测定乳牙菌斑中脂肪酸组成厦含量，将脂肪酸含量与患龋状况作相关性分析。结果乳牙菌斑含有9种直链饱和脂肪酸及3种直链非饱和脂肪酸。总脂肪酸含量在无龋组、高危组间差别有统计学意义（P〈0．05），C16：0脂肪酸含量在有龋组、无龋组间及无龋组、高危组间差别有统计学意义（P〈0．05）。结论 乳牙菌斑总脂肪酸、C16．0脂肪酸含量所示与乳牙龋病之关系可进一步探讨。     

In vitro effect of a resin infiltrant on different artificial caries-like enamel lesions

ObjectivesA resin infiltrant was employed for the treatment of active white spot lesions due to its ability to penetrate into the enamel pores and prevent the progression of the lesion. However, limited information is available about its mechanical effect on different artificial enamel lesions as well as on its resistance to further demineralization. Therefore, this study aimed to evaluate the effects of the Icon® infiltrant on different artificial caries-like enamel lesions and its resistance to new acid challenges.DesignArtificial lesions were produced in bovine enamel using three different protocols (demineralization/remineralization cycling, DE-RE; 8% methylcellulose gel, MC; and methyl ethyl diphosphonate solution, MHDP; n = 13). The specimens were treated with Icon® and subjected to a new acid challenge using DE-RE cycling. The surface and cross-sectional hardness were evaluated in sound, demineralized, treated and further demineralized enamel areas. Data were statistically analyzed using ANOVA and Tukey’s test (p < 0.05).ResultsAll of the demineralizing protocols produced subsurface artificial caries lesions. The infiltrant was able to partially recover the surface hardness and prevent further surface hardness loss in enamel previously demineralized using the DE-RE and MHDP protocols. In regard to cross-sectional hardness, no positive effect was found.ConclusionsThe effect of the infiltrant depends on the type of lesion created in vitro, and its action is limited to the lesion surface.     

离子导人促进乳、恒牙牙釉质表层氟渗透的比较分析

目的：应用离子导入技术对乳牙及恒牙牙釉质进行氟离子导入,观察离子导入对乳牙及恒牙牙釉质表层氟分布及含量的影响,比较离子导入促进氟在不同牙釉质表层的渗透效果。方法：分别收集30例无龋下颌乳中切牙及下颌恒前磨牙,将乳牙及恒牙样本沿唇舌向正中切开,分为对照组与实验组,对照组样本应用2％氟化钠溶液浸润,实验组样本用离子导入仪进行2％氟化钠溶液离子导入。利用电子探针检测乳牙及恒牙牙釉质表层200μm内的氟分布变化并进行统计学分析。结果：电子探针分析显示在对照组与实验组乳牙牙釉质表层均可见高密度氟分布,而恒牙牙釉质,两组样本的氟分布未见明显变化。统计分析显示乳牙实验组样本的氟含量在釉质表层100μm、150μm处明显高于对照组（P〈0．05）,而两组恒牙样本釉质中氟含量无显著差异（P〉0．05）,在釉质表层200μm内离子导入促进乳牙氟渗透的效果明显高于恒牙（p〈0．01）。结论：在实验技术指标相同的情况下,离子导入技术能够有效促进氟离子在乳牙釉质表层的渗透,而对于恒牙釉质表层氟的分布无明显影响。