三种充填剂治疗根面龋的微渗漏研究

目的：研究不同充填剂对根面龋治疗的微渗漏影响.方法：选择30个离体磨牙,用Dyract复合体,银汞合金,FujiII玻璃离子水门汀对根面龋进行充填治疗随机分为三组,对样本进行冷热循环、染液渗透实验,通过扫描电镜观察和测定充填体与牙体边缘微渗漏情况,进行统计分析.结果：FujiⅡ玻璃离子水门汀组（29.94-35.90）的缝隙宽度大于其它两组,银汞合金组（4.35-5.64）的缝隙宽度大于Dyract复合体组（1.91-4.91）.结论：Dyract复合体充填材料的微渗漏较小,能更好地预防继发龋和充填物的脱落,是治疗根面龋的良好材料.     

玻璃离子水门汀牙体充填后边缘封闭性的观察

目的：比较三种玻璃离子水门汀牙体充填修复后边缘封闭性的差别。方法：离体前磨牙80颗按要求制备洞型,随机分成4组,分别用三种玻璃离子水门汀（新世纪齿科材料有限公司玻璃离子水门汀I型、II型,日本GCFujiII）充填修复,另外一组用玻璃离子水门汀II型修复后再涂隔湿剂（凡士林）。经冷热交替试验（0℃～55℃,循环500次）,采用1%亚甲蓝染料渗入法观察充填体与牙体洞壁间边缘微渗漏的情况。结果：玻璃离子水门汀I型（普通型）边缘封闭性与其他各组存在显著差异（P〈0.01）;玻璃离子水门汀II型（树脂增强型）、GCFujiII与隔湿剂组边缘封闭性存在差异（P〈0.05）;玻璃离子水门汀II型与GCFujiII边缘封闭性比较不存在差异（P〉0.05）。结论：玻璃离子水门汀II型与GCFujiII边缘封闭效果相同;隔湿剂能降低微渗漏。     

超声龈上洁治术对全瓷冠边缘微渗漏的影响

目的：探讨超声龈上洁治术对全瓷冠边缘微渗漏的影响。方法：收集形态、大小基本一致的前磨牙48颗,全瓷冠牙体预备后随机分为2组（二氧化锆冠组和玻璃陶瓷冠组,每组24颗）,每组再随机分为2个亚组（树脂水门汀组和树脂改性玻璃水门汀组）。修复体粘接、固化、人工唾液保存24 h后,每个亚组内随机抽取3个样本进行超声龈上洁治60 s,另外3个样本为阴性对照组。将所有样本于室温下用5%品红溶液浸泡48 h,沿颊舌向切开,对样本冠边缘微渗漏情况进行双盲评分。采用SPSS 17.0软件包进行独立样本t检验,比较各组样本中修复体冠边缘微渗漏差异。结果：使用树脂加强型玻璃水门汀粘接的冠边缘微渗漏在超声龈上洁治后与阴性组有显著差异（P<0.05）,而使用树脂水门汀粘接的冠边缘微渗漏在超声龈上洁治后与阴性组无显著差异（P>0.05）。采用同种粘接剂时,无论是否接受超声龈上洁治术,二氧化锆全瓷冠与玻璃陶瓷冠之间微渗漏均有统计学差异（P<0.05）。结论：超声龈上洁治对树脂加强型玻璃水门汀粘接的二氧化锆和玻璃陶瓷冠边缘微渗漏有显著影响,而对树脂水门汀粘接的二氧化锆和玻璃陶瓷冠边缘微渗漏无显著影响。     

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目的对比4种充填材料的边缘微渗漏情况,为其临床应用提供合理指导。方法选择2013年1—6月青岛大学医学院附属医院口腔科因牙周病或阻生齿而拔除的健康新鲜后牙60颗,备洞后随机分为6组,每组10颗,分别使用Fihek Z250复合树脂（A1、A2组）、Ketac N100树脂加强型玻璃离子（B1组）、Ketac MolarEasymix型玻璃离子（B2、B3组）、F2000Compomer玻璃离子复合体（B4组）充填窝洞。其中A2组充填后充填体表面涂布AdperSingleBond2粘接剂,B3组充填后充填体表面涂布凡士林,而其他各组充填后表面不做任何处理。经冷热交替实验后,记录各组染料渗入窝洞壁与充填体之间的深度,并进行统计分析。结果A2组微渗漏最小,B2组微渗漏最大,与其他组（A1、B1、B3、B4）相比差异有统计学意义（P〈0．05）;A1、B1、B3、B4组间两两比较差异均无统计学意义（P〉0．05）。结论复合树脂、树脂加强型玻璃离子、玻璃离子复合体的边缘微渗漏均小于传统型玻璃离子;表面涂布隔湿剂后能增强上述材料的边缘封闭性能。     

根管充填材料边缘微渗漏体外实验研究

目的 对比4种充填材料的边缘微渗漏情况,为其临床应用提供合理指导。方法 选择2013年1—6月青岛大学医学院附属医院口腔科因牙周病或阻生齿而拔除的健康新鲜后牙60颗,备洞后随机分为6组,每组10颗,分别使用FiltekTM Z250复合树脂（A1、A2组）、KetacTM N100树脂加强型玻璃离子（B1组）、KetacTM Molar Easymix型玻璃离子（B2、B3组）、F2000 Compomer玻璃离子复合体（B4组）充填窝洞。其中A2组充填后充填体表面涂布Adper Single Bond 2粘接剂,B3组充填后充填体表面涂布凡士林,而其他各组充填后表面不做任何处理。经冷热交替实验后,记录各组染料渗入窝洞壁与充填体之间的深度,并进行统计分析。结果 A2组微渗漏最小,B2组微渗漏最大,与其他组（A1、B1、B3、B4）相比差异有统计学意义（P < 0.05）;A1、B1、B3、B4组间两两比较差异均无统计学意义（P > 0.05）。结论 复合树脂、树脂加强型玻璃离子、玻璃离子复合体的边缘微渗漏均小于传统型玻璃离子;表面涂布隔湿剂后能增强上述材料的边缘封闭性能。     

脱敏剂对水门汀边缘封闭性的影响

目的:评价脱敏剂对水门汀边缘封闭性的影响.方法:对48 颗离体牙进行牙体预备,暴露牙本质,随机分为4组:聚羧酸锌水门汀组、玻璃离子水门汀组、树脂加强型玻璃离子水门汀组、树脂水门汀组,每组根据脱敏剂不同再分为Gluma小组、SingleBond2小组、BisBlock小组和对照小组.应用水门汀粘固树脂被粘体于脱敏处理后的牙本质表面.每小组3 个样本.所有样本在50% 硝酸银溶液中渗透6 h,荧光显影12 h 后剖开,测量显微镜下记录银离子渗透距离.采用SPSS 13.0统计软件对实验数值进行分析,取α=0.05.结果:SingleBond2组的微渗漏最低;Gluma脱敏剂减少了树脂和玻璃离子水门汀的微渗漏;BisBlock 使树脂和玻璃离子水门汀的微渗漏增加.结论:SingleBond2表现出最好的封闭效果;Gluma和Bisblock脱敏剂对微渗漏的影响与联用的水门汀相关.     

根管充填后3种暂时充填材料的冠部封闭性能比较

目的：探讨根管充填后暂时充填材料的冠部封闭性能.方法：取105颗单根离体牙,分为12组,常规根管充填,并分别采用磷酸锌水门汀、玻璃离子水门汀和Dyract AP复合体封闭后,置于次甲基蓝液体和^125I标记的IgG溶液进行从冠方向根方的渗漏,1周、2周和6周后分别运用自显影技术或直接测量渗漏深度,统计分析.结果：各组均有渗漏,^125I标记IgG渗漏实验显示在6周时磷酸锌水门汀组的渗漏深度明显大于玻璃离子水门汀组和Dyract AP复合体组（P=0.008＜0.01）.结论：Dyract AP复合体和玻璃离子水门汀可能是远期效果较好的暂封材料.     

洞形设计对Ⅴ类洞充填体边缘微渗漏影响的实验研究

目的:探讨5种洞形设计对复合体及光固化玻璃离子水门汀(LGIC)充填的V类洞边缘微渗漏的影响。方法:选用100颗人离体恒后牙,制备5种不同洞形,用复合体及LGIC分别充填。在体视显微镜下测量染液在龈壁渗入深度。2例标本在扫描电镜下观察材料与牙体的结合情况。结果:1.复合体充填的洞壁封闭性较LGIC更佳; 2.同种材料龈壁微渗漏高于壁;3.同种材料不同洞形微渗漏深度的比较,在壁无统计学差异,在龈壁,复合体充填的洞缘角为150b的V形洞微渗漏较盒状洞严重, LGIC充填的洞缘角为120b和135b的V形洞微渗漏较盒状洞轻。结论:复合体充填的洞壁封闭性较LGIC更佳。建议V形洞洞缘角不可制备过大。     

几种市售商品充填材料密合度的实验研究

选用几种市售牙体充填复合树脂和玻璃离子水门汀充填Ⅴ类洞(龈壁由牙骨质和牙本质组成),采用染色法观察其边缘微漏的离体牙实验。发现不同充填材料存在不同程度的边缘微漏,酸处理洞缘可显著降低边缘微漏(P<0.05),窝洞的牙釉质壁渗漏显著低于牙骨质壁渗漏(P<0.01)。实验结果提示,充填材料的粘附性能,窝洞边缘的位置以及酸处理技术,都将影响牙体充填的治疗效果。     

可流动复合树脂充填楔状缺损的体外微渗漏研究

目的　研究可流动复合树脂充填楔状缺损离体牙模型的边缘微渗漏情况。方法　选择因正畸拔除的上颌前磨牙2 4个,于颊侧颈部釉牙骨质界处备V型洞后,随机分为3组,分别采用Aelieteflo可流动复合树脂,DyractAP复合体,GICTYPEII化学固化玻璃离子进行充填。经力循环、热循环后,2 %亚甲基蓝染色2 4h ,将每个牙齿自颊舌向沿长轴连续切3片。体视显微镜放大4 0倍观察充填体边缘染液渗漏情况。结果　3组间充填体微渗率差异有显著性(P <0 .0 0 1) ,以Aelieteflo材料的边缘微渗率最低(P <0 .0 5 )。3组牙合侧壁与龈侧壁微渗率间差异无显著性(P =0 .2 6 3)。结论　可流动复合树脂用于楔状缺损充填可以获得较好的边缘封闭性。     

Postoperative dental bleaching: effect of microleakage on Class V tooth colored restorative materials

The effect of 3 percent, 11 percent, and 16 percent carbamide peroxide bleaching solutions and 35 percent hydrogen peroxide bleaching gel on microleakage of Class V composite resins, resin modified glass ionomer cements, and compomer restorative materials together with corresponding (if indicated) fourth/fifth generation bonding agents was evaluated using previously extracted human teeth. Five groups of Class V cavity preparations were placed in enamel of the facial surfaces of 200 teeth. Groups A through D included 40 restorations each (4 different restorative materials and their accompanying bonding agent multiplied by 10 teeth) treated with 3 percent, 11 percent, and 16 percent carbamide peroxide bleach and 35 percent hydrogen peroxide bleach. Group E included 40 restorations without treatment of bleach and stood as the control. The restorative materials included were: Fuji II LC resin modified glass ionomer cement, Helioprogress composite resin/-Heliobond adhesive system, Aelitefil composite resin/Allbond 2 adhesive and Dyract compomer material/Prime & Bond adhesive system. Bleaching agents included were Rembrandt 3 percent peroxide gel, Perfecta 16 percent carbamide peroxide gel, White & Brite 11 percent carbamide peroxide solution and Superoxyl 35 percent hydrogen peroxide gel. All teeth were thermally stressed for 100 cycles and microleakage were assessed by dye penetration. The results were tabulated using Analysis of Variance (ANOVA) testing procedures. The Aelitefil composite resin material behaved the least favorably (relative to microleakage) compared to the other materials when exposed to various concentrations of dental bleaching agents.     

Protective effect of resin coating on the microleakage of Class V restorations following treatment with carbamide peroxide in vitro

This in vitro study evaluated the effects of a resin coating on the microleakage of Class V restorations due to bleaching. One-hundred and sixty Class V cavities were randomly restored with one of four different restorative materials (n = 40): a compomer (Dyract AP), a conventional glass-ionomer cement (Ketac Molar Easymix), a resin modified glass-ionomer cement (Fuji II LC) and a resin composite (Filtek Z350). For each kind of material, 40 restorations were divided into four subgroups: bleached with resin coating (group BC), bleached without resin coating (group B), immersed in artificial saliva with resin coating (group SC), immersed in artificial saliva without resin coating (group S). In groups B and BC, the specimens were bleached with 10% carbamide peroxide gel for eight hours daily, while groups SC and S were stored in artificial saliva instead. After 28-day treatment, all the samples were subjected to a dye penetration test using the multiple-sectioning technique. In addition, one more test was performed to investigate the color difference between the coated and uncoated tooth surface after bleaching. There was a statistically significant increase in cervical microleakage in the group B specimens of Fuji II LC and Ketac Molar Easymix compared to their respective control specimen (group S). These effects on microleakage were not found in the bleached specimens with resin coating (group BC). There was also no visually-detectable color difference between the coated and uncoated tooth surface. In conclusion, resin coating is an effective method for avoiding the bleaching-induced microleakage of glass-ionomer cement.     

Effect of bleaching agents on the microhardness of tooth-colored restorative materials

STATEMENT OF PROBLEM: There is no consensus concerning the effect of bleaching gels on microhardness of restorative materials. Information about the effect of whitening strips on microhardness of restorative materials is also limited. PURPOSE: The purpose of this study was to evaluate the effect of a bleaching gel and a whitening strip on the microhardness of 3 tooth-colored restorative materials. MATERIAL AND METHODS: Forty cylindrical specimens (6 x 2 mm) of each restorative material, including a nanohybrid composite resin (Grandio), a polyacid-modified composite resin (Dyract eXtra), and a glass-ionomer cement (Ionofil Molar AC), were prepared and stored in distilled water at 37 degrees C for 24 hours. The specimens were then polished using medium, fine, and superfine polishing disks and stored in 37 degrees C distilled water for 7 days. Specimens were divided into 4 groups (n=10). One group was selected for baseline Vickers hardness measurements (load 100 g, dwell time 20 seconds) of the top surfaces. The other 3 groups were treated for 21 days with 1 of the following: distilled water (control), bleaching gel (10% carbamide peroxide), or whitening strip (14% hydrogen peroxide). The top surfaces of the treated specimens were also subjected to the same hardness testing performed for the baseline specimens. Data were analyzed with 2-way analysis of variance and Tukey Honestly Significant Difference tests (alpha=.05). RESULTS: There were no significant differences in microhardness between the test groups of each restorative material. However, significant differences in microhardness were observed among restorative materials. For all test groups, composite resin showed the highest hardness values, whereas glass-ionomer cement presented the lowest (P<.05). CONCLUSION: The bleaching products used in this study did not adversely affect the microhardness of the restorative materials.     

Post-operative bleaching: effect on microleakage.

The effect of a carbamide peroxide bleaching gel on the microleakage of Class V resin composite restorations with two dentin bonding agents was evaluated using extracted human teeth. Class V cavity preparations were placed at the cementoenamel junction of the facial and lingual surfaces of 20 teeth for a total of 40 preparations. Half of the teeth were restored with Scotchbond 2/Silux Plus and half were restored with Prisma Universal Bond 3/AP.H. Five teeth were randomly selected from each of the two groups and were stored in water at 37 degrees C to serve as controls. The remaining teeth were exposed to a carbamide peroxide gel for three 2-hour periods per day for 9 days. The specimens were stored in distilled water at 37 degrees C except during treatment periods. All teeth were then thermally stressed for 100 cycles. Microleakage was assessed by dye penetration. The results demonstrated that the carbamide peroxide agent adversely affected the marginal seal of both restorative systems.     

The effect of bleaching agents on the microhardness of dental aesthetic restorative materials

This study investigated the effects of three home bleaching agents on the microhardness of various dental aesthetic restorative materials. The restorative materials were: feldspatic porcelain, microfilled composite resin and light-cured modified glass-ionomer cement and the bleaching agents Nite-White (16% carbamide peroxide), Opalescence (10% carbamide peroxide and carbapol jel) and Rembrandt (10% carbamide peroxide jel). A total of 90 restorative material samples were prepared 1 cm diameter and 6 mm thick and kept in distilled water for 24 h before commencing bleaching which was carried out for 8 h day-1 for 4 weeks. Microhardness measurements were then made using a Tukon tester. Statistically significant differences with respect to unbleached controls were found only for the feldspatic porcelain and microfilled composite resins (P <0.05) for Nite-White and Opalescence. All the bleaching agents decreased the microhardness of the porcelain and increased that of the light cured modified glass-ionomer cement. For the composite resin, whereas Nite-White increased its microhardness, the other bleaching agents decreased it. There were no significant differences between the bleaching agents for any of the restorative materials.     

An in vitro comparison of the bleaching efficacy of 35% carbamide peroxide with established intracoronal bleaching agents

AIM: To evaluate the bleaching efficacy of 35% carbamide peroxide, 35% hydrogen peroxide and sodium perborate for intracoronal bleaching of root filled discoloured teeth. METHODOLOGY: Extracted premolars were artificially stained using whole blood then root canal treatment was performed. After obturation, a 2 mm intermediate base was placed 1 mm below the buccal amelo-cemental junction. Intracoronal bleaching was performed in 11 teeth per group, using either 35% carbamide peroxide gel (group CP), 35% hydrogen peroxide gel (group HP) or sodium perborate mixed with distilled water (group SP). The bleaching agents were replaced after 7 days. The shade of the teeth was evaluated at day 0, 7 and 14. The results were analysed using Kruskal-Wallis one-way analysis of variance and Mann-Whitney U-test. RESULTS: At the end of 7 days, both groups CP and HP lightened by 8 +/- 3 Vita tab positions, respectively, whereas group SP lightened by 5 +/- 3 tab positions (P < 0.05). At the end of the second bleaching period at day 14, group CP and HP lightened by a further 2 +/- 2 and 2 +/- 3 tab positions, respectively, whereas group SP lightened by a further 3 +/- 4 tab positions. There were no statistical differences between groups at day 14. CONCLUSIONS: Thirty-five per cent carbamide peroxide and 35% hydrogen peroxide were equally effective for intracoronal bleaching, and significantly better than sodium perborate after 7 days. After 14 days, there were no significant differences between the groups. Thirty-five per cent carbamide peroxide can be recommended as an equally effective alternative to hydrogen peroxide for intracoronal bleaching.     

Effect of non-vital tooth bleaching on microleakage of coronal access restorations

This study evaluated the effect of non-vital tooth bleaching on microleakage of composite resin/bovine tooth interface at different post-bleaching times. A total of 320 teeth were cleaned. A pulp chamber access cavity was made at the lingual surface of each tooth. The teeth were randomly divided into four groups: SPH - sodium perborate + 30% hydrogen peroxide; SPW - sodium perborate + distilled water; CP-37% carbamide peroxide; and CON-distilled water (control). The bleaching agents were replaced every 7 days, over 4 weeks. Following bleaching procedures, the groups were divided into four subgroups (n = 20), according to the post-bleaching times: 0 (baseline), 7, 14 and 21 days. After that, the cavities were restored with an adhesive system (Single Bond; 3M Co., St Paul, MN, USA) and a composite resin (Z100/3M). The specimens were thermocycled, stained with 2% methylene blue solution (pH 7), and sectioned longitudinally. The teeth were evaluated blind and independently by three previously calibrated examiners, to provide representative scores. The data were submitted to Kruskal-Wallis and multiple comparison tests (alpha=0.05). At baseline and 7 days, the SPH group showed a higher degree of dye penetration than the CON (P=0.04). At 14 and 21 days, there were no differences among groups. The association of sodium perborate with 30% hydrogen peroxide or with water may affect the sealing ability of composite resin restorations performed up to 7 days after bleaching procedures.     

Dental effects of home bleaching gels and whitening strips on the surface hardness of resin composites

PURPOSE: To evaluate the effects of two bleaching gels and two whitening strips on surface hardness of four resin composites in vitro. METHODS: 60 cylindrical samples of each composite (Surefil, Charisma, Admira, Flowline) were prepared (4 mm thickness and 6 mm diameter) and stored in distilled water at 37 degrees C for 24 hours. These samples were randomly divided into six test groups (n=10). One group was selected for baseline and Vickers microhardness measurements (load= 100 g, dwell time 20 seconds) were taken immediately. The other groups were treated for 21 days with one of the following: distilled water (control), containing 10% carbamide peroxide bleaching gel (Perfect Bleach), 16% carbamide peroxide bleaching gel (Viva Style), 5.3% hydrogen peroxide whitening strips (Crest Whitestrips) and 14% hydrogen peroxide whitening strips (Crest Whitestrips Supreme). The treated samples were also subsequently subjected to the same microhardness testing by using the same method as applied to the baseline measurements. Data were analyzed statistically (alpha = 0.05). RESULTS: Overall, the lowest surface hardness value was observed in baseline measurements. An increase in surface hardness was noted in all of the other groups. The higher surface hardness values were found in control, whitening strip (5.3% HP) and bleaching gel (10% CP) groups than whitening strip (14% HP) group. Bleaching gel (16% CP) was statistically different from only baseline measurements. In addition, regardless of the tested groups, statistically significant differences in surface hardness were observed between composite materials. Surefil showed the highest hardness values while Flowline presented the lowest hardness values.     

Effect of bleaching on restorative materials and restorations--a systematic review.

OBJECTIVE: Internal and external bleaching procedures utilizing 3-35% hydrogen peroxide solutions or hydrogen peroxide releasing agents, such as carbamide peroxide or sodium perborate, can be used for whitening of teeth. The purpose of the review article was to summarize and discuss the available information concerning the effects of peroxide releasing bleaching agents on dental restorative materials and restorations. SOURCES: Information from all original scientific full papers or reviews listed in PubMed or ISI Web of Science (search term: bleaching AND (composite OR amalgam OR glass ionomer OR compomer OR resin OR alloy) were included in the review. DATA: Existing literature reveals that bleaching therapies may have a negative effect on physical properties, marginal integrity, enamel and dentin bond strength, and color of restorative materials as investigated in numerous in vitro studies. However, there are no reports in literature indicating that bleaching may exert a negative impact on existing restorations requiring renewal of the restorations under clinical conditions. CONCLUSION: Bleaching may exert a negative influence on restorations and restorative materials. Advice is provided based on the current literature to minimize the impact of bleaching therapies on restorative materials and restorations.     

The marginal seal of a flowable composite, an injectable resin modified glass ionomer and a compomer in primary molars--an in vitro study

The present study was carried out to compare the marginal microleakage of some newer materials viz. a flowable composite, an injectable resin modified glass-ionomer and a compomer in Class I cavities of 30 non carious primary molars. After 0.5% basic fuchsin dye penetration and sectioning, the teeth were studied under stereomicroscope. The results obtained revealed that flowable composite showed significantly lower microleakage (p<0.05) as compared to injectable resin-modified glass ionomer and compomer. However, no significant difference was observed when injectable resin modified glass-ionomer cement was compared to compomer. This concludes that flowable composite materials adhere better to the primary teeth than resin modified glass ionomer and compomer.