光固化型和化学固化型玻璃离子水门汀与光固化复合树脂间的抗剪粘接强度

测定两种光固化型玻璃离子水门汀（ＬＧＩＣ）和两种化学固化型玻璃离子水门汀（ＧＩＣ）与光固化复合树脂间的抗剪粘接强度。结果显示：不论对ＬＧＣ，ＧＩＣ表面酸蚀与否，ＬＧＩＣ与光固化复合树脂间的粘接强度均比ＧＩＣ高，且相互极显著（Ｐ＜０．０１）；酸蚀ＬＧＩＣ，ＧＩＣ表面，其与光固化复合树脂间的粘接强度都会提高，相差极显著（Ｐ＜０．０１）。     

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目的评价不同黏结剂用于光固化复合树脂充填体表面托槽黏结的效果。方法2012年3月于中国医科大学口腔医学院正畸科制作10个自凝树脂长方体试件,在其4个表面制备窝洞并行光固化复合树脂充填。将40个树脂充填体随机分为A、B、C、D组（每组10个）,分别用京津釉质黏结剂、3M Unite化学固化黏结剂、3M Transbond光固化黏结剂和可乐丽菲露AP—X光固化复合树脂黏结金属托槽,进行抗剪切强度测试,并测评光固化树脂面黏结剂残留指数（ARI积分）。结果4种黏结剂的抗剪切强度分别为：A组（7．763±1．240）MPa;B组（8．231±0．338）MPa;C组（8．654±0．916）MPa;D组（8．349±0．820）MPa。4种黏结剂的抗剪切强度均达到临床要求,其中c组与A组的抗剪切强度差异有统计学意义（P〈0．05）,其余各组间的抗剪切强度差异无统计学意义（P〉0．05）。各组的ARI积分差异无统计学意义（P〉0．05）。结论在经过打磨粗糙表面处理后的光固化复合树脂表面黏结托槽时,4种黏结剂均能满足临床要求。其中3MTransbond“光固化黏结剂产生的抗剪切强度最大。     

Nd：YAG激光处理与磷酸酸蚀牙本质后抗剪切粘结强度的比较研究

应用４组能量参数不同的Ｎｄ：ＹＡＧ激光处理及磷酸酸蚀牙本质表面后，分别与光固化复合树脂粘结，比较各激光处理组与酸蚀组之间抗剪切粘结强度的差别。结果表明：激光处理组的抗剪切粘结强度高于酸蚀组，其中，４０ｍＪ１５ｐｐｓ激光处理组的抗剪切粘结强度明显高于酸蚀组（Ｐ〈０．０１），并高于其它激光处理组（Ｐ〉０．０５）。讨论了Ｎｄ：ＹＡＧ激光对牙本质表面的作用，及其与光固化复合树脂良好粘结机理和其临床应用的安     

激光处理牙釉质,牙本质与复合树脂的粘结研究

对脉冲钕玻璃激光辐射离体牙釉质，牙本质进行表面扫描电镜观察及测定辐射面与光固化复合树脂间粘结强度。结果表明：激光处理牙轴质表面呈云絮状熔融，与复合树脂粘结强度高于对照组，有非常显著性差异（Ｐ〈０．０１），低于酸蚀组，有显著性差异（Ｐ〈０．０５），激光处理牙本质表面呈重叠蜂窝状熔融，与复合树脂粘结强度高于对照组，有非常显著性差异（Ｐ〈０．０１），与酸蚀组无显著性差异（Ｐ〉０．０５），激光处理牙釉质及     

变形链球菌在三种直接修复用牙色材料抛光表面的早期黏附观察

目的 研究变形链球菌在直接修复用牙色材料表面的早期黏附情况,以期为临床工作提供参考.方法 选用3种直接修复用牙色材料,复合树脂(CR)、玻璃复合体(Giomer)和树脂改性玻璃离子(RMGIC),每种材料制备5个试样,试样(8 mm×8 mm×2 mm)经表面抛光和被覆人工唾液后,进行变形链球菌(Streptococcus mutans,Sm)黏附实验.2h后应用激光共聚焦显微镜(confocal laser scanning microscope,CLSM)和荧光染色技术观察材料表面细菌黏附情况,并采用多独立样本非参数检验方法分别对死菌、活菌黏附面积百分比(Ad、Av)及二者比值(Ad/Av)进行统计学分析,检验水准为双侧α =0.05.结果 CLSM下可见所有材料表面均有细菌黏附,其中主要为活菌.3种材料间的Ad、Av差异均有统计学意义(P＜0.05).复合树脂、玻璃复合体Ad[M(Q)] [0.007％(0.037％)、0.011％(0.028％)]显著小于树脂改性玻璃离子[0.082％(0.082％)],P＜0.05;复合树脂、玻璃复合体Av[M(Q)][0.103％ (0.162％)、0.067％ (0.181％)]显著小于树脂改性玻璃离子[0.690％(0.482％)],P＜0.05.但玻璃复合体的Ad/Av[M(Q)] [0.250(0.188)]显著高于复合树脂[0.069(0.125)]和树脂改性玻璃离子[0.114(0.051)],P＜0.05.结论 变形链球菌在直接修复用牙色材料表面的早期黏附与材料种类密切相关.     

十种纳米填料光固化复合树脂聚合收缩性能的比较与评价

目的 探讨10种纳米填料光固化复合树脂的聚合收缩情况,评价纳米填料在光固化复合树脂聚合收缩性能中的作用.方法 采用激光位移传感器进行非接触式测量,实时监测10种纳米填料光固化树脂(CM:Clearfil Majesty; CX:Ceram·X;F:Fulfil;E:Estelite α;PM:Premisa; TN:Tetric N-Ceram restorative;S:Spectrum TPH3;TB:Tetric Bulk Fill;Z:Z350XT;P:P90)的聚合收缩情况.测量光固化时的体积收缩率、收缩速率峰值以及到达峰值的时间.采用单因素方差分析10种材料的差异.结果 10种纳米填料光固化树脂的体积收缩率差异有统计学意义(P＜0.01).10种纳米填料光固化树脂的体积收缩率范围为1.20％ ～ 3.09％,P＜PM ＜Z≈E ＜TN≈CM≈TB ＜CX ＜S ＜F,其中Z与E、TN与CM间差异无统计学意义,体积收缩率较接近.收缩速率峰值范围为2.14～ 14.76 μm/s,到达峰值的时间范围为3.29～5.39 s.结论 10种纳米填料复合树脂的聚合收缩差异显著,填料含量和粒径对复合树脂聚合收缩有一定影响作用,增加填料含量,减小纳米填料的粒径,有助于降低聚合收缩率.     

5种后牙复合树脂耐磨耗性能的体外评价

目的：比较5种后牙复合树脂的耐磨耗性能,探讨影响耐磨耗性能的因素。方法：取Helio-molar HB（A）、Solitaire 2（B）、Filtek P60（C）、Ecusphere－Carat（D）、Tetric Ceram HB（E）5种后牙复合树脂和银汞合金（F）,制成磨耗试样,用显微硬度计测定其表面硬度后,分别置于V型牙科磨耗试验机上,以不锈钢球为对磨偶件、萤石粉为磨耗介质,在磨耗压力为3N的条件下对试样摩擦6万次;然后,用三维形貌仪测定试样的体积磨损量和磨损面粗糙度,SEM观察其磨损表面形貌。结果：各材料体积磨损量由小到大依次为：F＜C＜B≈E≈A＜D（P＜0．05）;各材料硬度由低到高依次为：A＜B＜D＜E＜C＜F（P＜0．05）;C、D磨损表面较为平整,呈现典型的磨料磨损特征,A、B、E表面较为粗糙,有明显的材料疲劳磨损特征;各树脂的体积磨损量和磨损面粗糙度均与其硬度值呈负相关性（P＜0．05）。结论：后牙复合树脂的硬度越高,耐磨耗性越好,磨损面粗糙度越低;超微填料含量多者主要表现为疲劳磨损,超微填料含量少者主要表现为磨料磨损。     

光固化型和化学固化型玻璃离子水门汀与光固化复合树脂间的…

测定两种光固化型玻璃离子水门汀（ＬＧＩＣ）和两种化学固化型玻璃离子水门汀（ＧＬＣ）与光固化复合树脂间的抗剪粘接强度。结果显示，不论对ＬＧＩＣ，ＧＩＣ表面酸蚀与否，ＬＧＩＣ与光固化复合树脂间的粘接强度均化ＧＩＣ高，且相差极显著；酸蚀ＬＧＩＣ，ＧＩＣ表面，其与光固化复合树脂间的粘接强度都会提高，相差极显著。     

3种充填材料应用于牙颈部非龋性缺损的边缘封闭性研究

目的　比较3种不同材料充填牙颈部非龋性硬组织缺损后的密合度及微渗漏情况,为临床选择合适的修复材料提供借鉴。方法　拟收集临床即刻拔除的无龋前磨牙120颗,随机分为3组,每颗牙颊面近颈1/3处制备V类洞,分别充填GC Fuji Ⅱ光固化玻璃离子、Polofil Supra（波洛菲）通用型光固化树脂及3M z350纳米树脂。通过染料渗透实验,倒置金相显微镜下测量充填体边缘微缝隙的宽度及染料渗漏程度。结果　3种充填材料边缘均有染料渗入,渗入深度由小到大排序依次为:3M z350树脂＜波洛菲通用型光固化树脂＜GC Fuji II光固化玻璃离子,3组比较均有统计学差异（P＜0.01）;显微镜下测量3种充填物边缘与牙体间的缝隙宽度分别为:GC Fuji II光固化玻璃离子（22.62±2.46）μm、波洛菲通用型光固化树脂（15.91±2.51）μm、3M z350纳米树脂（15.16±2.12）μm。波洛菲与z350纳米树脂相比无差异（P＞0.05）,2种复合树脂材料与GC玻璃离子均有差异（P＜0.05）。结论　波洛菲树脂与z350纳米树脂边缘封闭性优于GC Fuji II光固化玻璃离子。     

含氟涂料和含氟牙膏对釉面再矿化和抗酸作用的实验研究

目的：观察含氟涂料与含氟牙膏对釉质表面再矿化和抗酸作用。方法：取牛恒切牙制备釉质片;统一酸蚀脱矿后随机分为4组（n＝3）;分别为生理盐水（A组对照）、Duraphat含氟涂料（B组）、Fluor Protector含氟涂料（C组）、含氟牙膏规律处理（D组）;处理期间标本置于人工唾液孵育2周;再次酸蚀;各阶段均用显微硬度仪测定釉面显微硬度、扫描电镜观察釉面,图像分析电镜下釉面微孔隙面积差异;统计分析。结果：首次酸蚀后釉面明显脱矿。分组处理2周,A组釉面再矿化不明显;B组和C组釉面形成涂料保护层;D组釉面可见明显再矿化。再次酸蚀后：A组和D组显微硬度下降,B组和C组涂料保护层有明显抗酸作用。再次酸蚀后,A组和D组釉面微孔隙面积增加（P＜0．05）,但D组小于A组（P＜0．05）;B组、C组无显著变化（P＞0．05）。结论：含氟涂料在釉面形成保护层,具有抗酸蚀和促进釉面再矿化作用;含氟牙膏能促进脱矿釉面再矿化,抗酸作用较弱。     

Effect of topical fluoride application on toothbrushing abrasion of resin composites.

OBJECTIVES: This in vitro study assesses toothbrushing abrasion of a microfill (Heliomolar Radioopaque) and a hybrid composite (Herculite XRV) after application of two acidic fluoride agents. METHODS: Thirty-six specimens of each resin composite were fabricated, ground flat and polished. Subsequently the 36 samples of each material were evenly assigned to three groups. In the first group, samples were treated with the fluoride varnish Bifluorid 12 (5.5% F, pH 5.6), in the second group with Elmex Fluid (1.25% F, pH 4.3). In the third group, specimens remained unfluoridated (controls). After 8h, the samples were subjected to toothbrushing abrasion (2000 brushing strokes, load: 250 g) in an abrasive slurry. Fluoridation and brushing abrasion were repeated twice. Afterwards, abrasion of the materials was quantitatively determined with a laser profilometer and statistically analyzed (ANOVA). RESULTS AND SIGNIFICANCE: With Herculite both, Bifluorid 12 (P = 0.0001) and Elmex Fluid (P = 0.0001) led to a significant increase of brushing abrasion compared to the non-fluoridated group. However, no significant difference was observed between the two fluoridation regimes. Heliomolar showed a tendency towards higher abrasion after treatment with Elmex Fluid compared to Bifluorid 12 (P = 0.0496) and the non-fluoridated group (P = 0.0496), whereas treatment with Bifluorid 12 yielded no significant difference compared to the non-fluoridated Heliomolar specimens. Fluoridation of Herculite resulted in a 106-121% increase of abrasion, whereas Heliomolar only showed an increase by 5-30%. Application of the acidic fluoride products used led to an increase in toothbrushing abrasion of the tested composite restorative materials. However, clinical long-term studies are needed to determine the effect of topical fluoride regimes on resin composite materials.     

Effects of topical fluoride agents on artificial enamel lesion formation in vitro.

OBJECTIVE: The purpose of this study was to assess the effects of topical fluoride agents on enamel erosion in vitro. METHOD AND MATERIALS: Ten premolars extracted for orthodontic purposes were sectioned buccolingually and then longitudinally into two parts, so that four specimens were obtained from each tooth. The specimens were randomly assigned to one of four groups. The following topical fluoride agents were applied to the specimens: 1% titanium tetrafluoride (0.32 MF) for 1 minute; Duraphat (2.26% F) and Elmex (1.25% F) for 4 minutes. In the control group, no solution was applied. The specimens were treated with an artificial caries solution for 4, 8, 12, and 16 days. Calcium (Ca++) concentration was determined by an atomic absorbtion spectrophotometer, while fluoride (F-) concentration was determined with an ion-selective electrode. One-way analysis of variance tests were performed on cumulative concentrations of calcium and fluoride at days 4, 8, 12, and 16. RESULTS: Specimens treated with titanium tetrafluoride lost significantly less calcium than did specimens in the other two test groups at all time periods. Titanium tetrafluoride-treated specimens released significantly less fluoride than did Duraphat- or Elmex-treated specimens at day 16. CONCLUSION: Titanium tetrafluoride was found to be more effective than the other fluoride agents in preventing artificial enamel lesion formation.     

In vitro effect of topical fluorides on sealant materials.

The purpose of this study was to determine by visual inspection and by scanning electron microscopy (SEM) whether commercially available, topical, acidulated phosphate fluoride (APF) and neutral sodium fluoride (NaF) agents cause surface roughening of five sealant materials: two unfilled resins, two filled resins, and one glass-ionomer material. In addition, the effect of treatment with 1.23% APF and sonification on weight of an unfilled and a filled sealant was compared to treatment with controls. Unfilled sealants exhibited no surface changes visually or on micrographs following any treatment. Filled sealants and the glass-ionomer sealant exhibited visually apparent changes depending on the treatment. SEM inspection of filled sealants with visually apparent changes showed loss of filler particles whereas the glass-ionomer sealant exhibited apparent destruction both of the matrix and the filler particle. No significant differences in weight were found between sonicated and unsonicated specimens. However, significant loss of weight was found with filled sealant specimens, but not unfilled sealant specimens, treated with 1.23% APF gel as compared with the specimens treated with water. The results of this in vitro study indicate that preventive therapies that combine use of topical fluorides and sealants may cause deterioration of filled sealants and glass-ionomer sealant material, but not unfilled sealants.     

In Vitro Effect of Topical Fluorides on Sealant Materials

The purpose of this study was to determine by visual inspection and by scanning electron microscopy (SEM) whether commercially available, topical, acidulated phosphate fluoride (APF) and neutral sodium fluoride (NaF) agents cause surface roughening of five sealant materials: two unfilled resins, two filled resins, and one glass-ionomer material. In addition, the effect of treatment with 1.23% APF and sonification on weight of an unfilled and a filled sealant was compared to treatment with controls. Unfilled sealants exhibited no surface changes visually or on micrographs following any treatment. Filled sealants and the glass-ionomer sealant exhibited visually apparent changes depending on the treatment. SEM inspection of filled sealants with visually apparent changes showed loss of filler particles whereas the glass-ionomer sealant exhibited apparent destruction both of the matrix and the filler particle. No significant differences in weight were found between sonicated and unsonicated specimens. However, significant loss of weight was found with filled sealant specimens, but not unfilled sealant specimens, treated with 1.23% APF gel as compared with the specimens treated with water. The results of this in vitro study indicate that preventive therapies that combine use of topical fluorides and sealants may cause deterioration of filled sealants and glass-ionomer sealant material, but not unfilled sealants.     

The effect of topical fluoride treatment on enamel fluoride uptake and the tensile bond strength of an orthodontic bonding resin

Enamel demineralization occurring adjacent to directly bonded orthodontic attachments is of great concern to orthodontists. The topical application of fluorides to enamel surfaces before acid etching and the bonding of the attachments is not recommended by many investigators. The objective of this study was to determine the enamel fluoride acquired from various topical fluoride agents and to determine the effect of the acquired fluoride on the tensile bond strength of an orthodontic bonding system. Fifty extracted maxillary central incisors were mounted in cups and the facial surfaces of the crowns were polished on 600-grit silicon carbide paper. Enamel microbiopsies were performed just off the midpoint of each tooth. Ten teeth served as controls and received no topical fluoride treatment, while a similar number were treated with either APF, SnF2, Duraphat, or Fluor Protector. The teeth were suspended in synthetic saliva 4 minutes after fluoride application. The topical fluoride agents were removed after 24 hours and the teeth were again suspended in synthetic saliva at 37 degrees C for 7 days. Enamel biopsies were again performed just off the midpoint of each tooth on the side not previously biopsied. The enamel surfaces were etched for 1 minute and the tensile bond strength of Concise orthodontic bonding system to the etched enamel surfaces was determined. The enamel surfaces acquired significantly different amounts of fluoride from the topical fluoride agents, but the bond strengths to these surfaces were not significantly different. The results of this in vitro study suggest that the application of topical fluoride agents to enamel surfaces 7 days before the bonding of orthodontic attachments will not have an adverse effect on bond strength.     

The effect of different bleaching agents on the surface texture of restorative materials

This blind in vitro study evaluated the effect of a home and an in-office bleaching agent on the surface texture of different tooth-colored restorative materials. Four composites (a hybrid, a flowable, a microhybrid and a nano-hybrid), an ormocer and a ceramic were used, and 2 bleaching agents were tested: 38% hydrogen peroxide and 15% carbamide peroxide. For 38% hydrogen peroxide, the surface morphology of the restorative materials was evaluated after the following time periods: before bleaching, after 15, 30 and 45 minutes of bleaching, 24 hours and 1 month after bleaching. For 15% carbamide peroxide, the time periods were: before bleaching, after 8 and 56 hours of bleaching and 24 hours and 1 month after bleaching. For the 4 composite materials and the ormocer, 2 samples groups were prepared; in 1 group, the specimens were polished and in the other, they stayed unpolished. For the ceramic group, polished samples were prepared. For every material, 3 samples per category and time period were prepared, respectively. Subsequently, the appropriate bleaching procedure was performed on samples of every group. Scanning electron micrographs were produced at 60x, 200x and 2000x magnifications of respective areas of the samples. The results showed that the effect of bleaching on the surface texture was material- and time-dependent. Within the limitations of this study, it was concluded that bleaching with 38% hydrogen peroxide and 15% carbamide peroxide did not cause major surface texture changes on the polished surfaces of the restorative materials.     

Effects of professionally applied topical fluorides on surface hardness of composite-based restoratives

This study investigated the effects of professionally applied topical fluorides on the surface hardness of a composite (Spectrum TPH), a compomer (DyractAP) and a giomer (Reactmer). Thirty specimens of each material were fabricated and stored in distilled water at 37 degrees C for one week. These specimens were then randomly divided into five groups of six and treated for 36 hours at 37 degrees C with one of the following: distilled water (control), 1.23% acidulated phosphate fluoride (APF) foam, 0.9% neutral foam, 1.23% APF gel and 0.4% stannous fluoride gel. The treated specimens were subsequently subjected to microhardness testing (load = 500 gf; dwell time = 15 seconds). Results were analyzed using ANOVA/Scheffe's test (p<0.05). The effects of topical fluoride application on surface hardness was material dependent. For all materials, treatment with APF gel and foam significantly reduced surface hardness when compared to the control. KHN values after exposure to APF gel were consistently the lowest and ranged from 4.53 to 15.97. Control KHN values were higher, ranging from 32.88 to 47.47. The surface hardness of the compomer was also significantly reduced after exposure to neutral foam. Therefore, the use of professionally applied topical fluorides, especially APF gel and foam, may be detrimental to the long-term durability of composite-based restoratives.     

Uptake of fluoride by sound and artificially carious enamel in vitro following application of topical sodium and amine fluorides

The aim of this investigation was to compare fluoride uptake and retention by sound and artificially carious enamel, after the topical application of a neutral sodium fluoride solution (NaF) or a commercial preparation containing aqueous amine fluorides (AF) 297 and 335 (Elmex Fluid, GABA International, Basel, Switzerland). Ten pairs of extracted premolars were used, one of each pair being treated with NaF and the other with AF. A lactic acid gel technique was used to produce artificial caries lesions on one-half of the buccal surface of the premolar crowns. Estimates at selected depths of pretreatment fluoride concentration, uptake and retention were made using a step-wise acid-etch sampling technique. AF produced much greater uptake than NaF, the difference being most marked in the deeper layers of the artificial lesions, suggesting that the amine fluorides had a strong affinity for demineralized enamel. After storage in normal saline for 1 week during which partial loss of the acquired fluoride occurred, the percentages retained ranged from 37 (NaF) to 65 percent (AF). It was concluded that AF enhanced both uptake and retention of fluoride by (artificial) early enamel caries lesions.     

Comparison of three topical fluorides using computer imaging

The purpose of this in vitro study was to evaluate the short and long-term effectiveness of fluoride varnish and compare it with the two most commonly used topical fluorides, i.e., fluoride gel and foam. A second purpose of the study was to compare the effectiveness of these preparations on primary and permanent teeth. Enamel slabs with a thickness of 500 microns were obtained from caries free primary molars and premolars. They were divided into four groups: control, foam (F), gel (G) and varnish (V). Fluorides were applied to the enamel slabs according to the manufacturer's instructions and were placed in a 5.1 pH acidic gel for one week. The amount of demineralization from the enamel was measured by calculating the amount of light reflected from these surfaces. This was done by using a Charged Couple Device attached to a high resolution microscope with image processing software, Optima 5.22. The enamel slabs were placed in a freshly prepared acidic gel for a second week without application of fluorides. This was done to mimic a situation where fluoride is eventually brushed away from teeth. Reflective images were recorded under the previously described conditions. A two-way analysis of covariance was used to compare the treatments. The results showed no statistically significant difference (with Bonferroni correction) in the effectiveness of different fluoride preparations over the short-term (Week I comparison; p-values: F vs. G 0.079, F vs. V 0.030, G vs. V 0.44). However, the long-term protection provided by fluoride varnish was far more than fluoride gel and foam (Week II comparison; p-values: F vs. G 9X10-5, F vs. V 7X10-8, G vs. V 1X10-4). Fluorides were equally effective for both primary and permanent enamels (p-value 0.24). The results of this study suggest that fluoride varnish is beneficial for use with white spot lesions, newly erupted permanent teeth and early decalcification in primary dentition.     

Enamel fluoride uptake affected by site of application: comparing sodium and amine fluorides

In enamel fluoride uptake studies, the most frequently sampled site is the middle third of the buccal surface. Because different parts of the enamel surface vary in fluoride concentration, the present study investigated fluoride uptake at contrasting sites using two different topical agents. One was a neutral aqueous solution of sodium fluoride containing 2% w/w of fluoride, and the second was an aqueous solution of two amine fluorides containing 1% w/w of fluoride. The enamel of 10 pairs of clinically sound extracted human premolars was etched initially and after treatment with one of these agents on the cervical and middle thirds of the buccal surface and on the proximal surface, yielding the pre- and post-treatment fluoride concentrations of these sites at depths of 5 and 10 microns from the surface. Enamel treated with the amine F solution had significantly higher fluoride uptakes at all sites compared to the NaF-treated specimens. The differences in uptake from the two agents varied with site, being smallest for the buccal middle third enamel and greatest for the proximal enamel. It is suggested that these results relate to possible differences in enamel maturation or to the presence of initial proximal caries, and the greater affinity of amine fluoride for porous enamel. The findings emphasise the importance of obtaining site-specific data in the study of fluoride in enamel.