不同制洞方法及充填材料对乳牙充填体边缘微渗漏的影响

目的了解乳牙采用牙钻和Er.YAG激光制洞后充填不同材料边缘微渗漏情况。方法下颌乳中切牙120颗,随机分为十组,采用牙钻和Er.YAG激光制洞后充填不同材料,各组随机取出两颗,扫描电镜观察充填物与洞壁结合情况。其余样本染色,体式显微镜下观察微渗漏情况并记分。结果扫描电镜观察结果:机械备洞组充填物与牙体之间存在明显缝隙,激光制洞充填物与牙体之间无明显缝隙,局部出现融合;前四组明显观察到激光制洞充填物边缘密合度优于牙钻制洞充填物边缘;机械备洞和激光制洞结合酸蚀粘接复合树脂充填,密合度最好。体式显微镜边缘微渗漏观察结果:(1)不同制洞方法,同种充填材料充填边缘微渗漏染料渗入程度不等,结果均无显著性差异(0.05)。(2)不同制洞方法,玻璃离子充填边缘微渗漏均明显高于其余材料充填,有显著性差异(P<0.05);自酸蚀粘接复合体充填边缘微渗漏均高于酸蚀粘接复合树脂充填,有显著性差异(P<0.05);激光制洞,酸蚀粘接复合体充填边缘微渗漏明显高于酸蚀粘接复合树脂充填,有显著性差异(P<0.05)。结论 (1)不同制洞方法,对充填体边缘密合及微渗漏有一定影响。Er.YAG激光制洞优...     

Nd:YAG激光对不同充填材料牙本质边缘微渗漏的影响

目的 评价Nd:YAG激光对不同充填材料与牙本质之间边缘微渗漏的影响。方法 选用人离体前磨牙36颗,制备V类洞,随机分为激光组和对照组,激光组使用80 rnJ、10 Hz脉冲Nd:YAG激光照射后,分别用全酸蚀粘接树脂、自酸蚀粘接树脂和玻璃离子充填洞型,对照组不使用激光,同样用如前所述的3种材料充填洞型。将所有标本浸泡在2%亚甲基蓝溶液中24 h后,用金刚砂片从颊舌向通过充填物中央纵向切开牙体,显微镜下观察龈壁染料渗透的深度。采用SAS8.0软件对数据进行统计学处理。结果 经Nd:YAG激光照射后尽管3种材料与牙本质之间微渗漏程度均有降低趋势,但只有玻璃离子组激光照射后较未照射组微渗漏降低具有统计学意义(P<0.05)。结论 脉冲Nd:YAG激光照射牙本质壁,在一定程度上可能会减少玻璃离子充填材料与洞壁的微渗漏。     

脉冲Nd:YAG激光照射牙本质后对光固化树脂充填体边缘微渗漏的影响

目的研究脉冲Nd：YAG激光照射牙本质后对光固化树脂充填体边缘微渗漏的影响，以探讨脉冲Nd-YAG激光在龋病治疗中的临床应用意义。方法选用正畸要求拔除的正常双尖牙30颗，随机分为A。B，C三组，每组10颗，用高速裂钻备洞（洞长、宽为3mm；洞深为2mm），A组为对照组，常规酸蚀树脂充填；B，C两组分别用50mJ，10Hz和100mJ，10Hz的脉冲Nd：YAG激光能量照射窝洞牙本质壁30s后树脂充填，分别用体视显微镜和扫描电镜观察充填体边缘和洞壁结合情况。结果．体视显微镜下观察：A组的牙本质洞壁与光固化树脂充填体间染料渗入较多，着色较深；B、C组的牙本质洞壁与光固化树脂充填体间染料渗入较少，着色较浅。扫描电镜下观察：B、C组的牙本质洞壁与光固化树脂充填体间裂隙明显小于未经激光处理的对照组。结论脉冲Nd：YAG激光处理牙本质后进行光固化复合树脂充填，可以减少充填体微渗漏，有利于充填的成功．     

Nd：YAG激光照射对根尖倒充填术窝洞封闭性影响的初步研究

目的:探讨Nd:YAG激光照射对根尖倒充填术封闭性的影响.方法:将根管形态相近的52 颗牙齿(前牙35 颗,前磨牙17 颗)随机分成5 组,每组10 颗,其余2 颗为电镜观察标本备用牙.去除牙冠,进行常规根管充填后去除根尖2 mm,用高速球钻将截面预备成碟形洞面.除第1 组外,分别用Nd:YAG激光以不同的时间和不同的方式(涂墨水与不涂墨水)照射洞面,用玻璃离子倒充填后进行微渗漏实验.扫描电镜观察激光处理后窝洞表面结构的改变,分析激光改善窝洞密封性的可能机制.结果:Nd:YAG激光照射组微渗漏程度显著低于对照组(P<0.01),并且涂墨汁组的微渗漏比未涂墨汁组的微渗漏明显减少(P<0.01).激光照射20 s组微渗漏明显低于照射10 s组(P<0.01).结论:Nd:YAG激光照射倒充填窝洞可以增加玻璃离子倒充填窝洞的封闭性.     

铒激光备洞对牙体与充填体间纳米渗漏和粘结强度的影响

目的评价铒(Er:YAG)激光和高速涡轮手机备洞,对复合树脂充填后牙体与充填体间纳米渗漏和粘结强度的影响。方法选32颗离体前磨牙平均分成两组,对照组用高速涡轮手机备洞;实验组用Er:YAG激光备洞,随后进行光固化复合树脂充填。两组各取8颗,进行纳米渗漏测试,扫描电镜(scanning electron micrographic,SEM)观察渗漏情况。其余样本检测微拉伸强度。使用SPSS 20.0统计软件对各组微拉伸强度进行独立样本t检验。结果在牙体与充填体间,实验组几乎没有纳米渗漏产生,对照组则产生纳米渗漏带。微拉伸强度:对照组(16.10±4.91)MPa,实验组(26.53±3.61)MPa,实验组微拉伸强度大于对照组,两组间差别有统计学意义(P<0.05)。结论与涡轮手机相比,Er:YAG激光备洞的纳米渗漏程度更低,粘结强度更好。     

Nd:YAG激光辅助复合体治疗根面龋的即刻脱敏作用及临床效果观察

目的：观察Nd：YAG激光辅助Dyract复合体治疗老年人根面龋的即刻脱敏效果及充填修复效果。方法：选择66例老年忠者的162颗临床诊断为根面龋并有牙本质过敏症的患牙，随机分成2组，实验组用脉冲Nd：YAG激光照射窝洞后，用光固化Dyract复合体充填修复，对照组用光固化Dyract复合体直接充填修复。观察2组的即刻脱敏效果及半年、一年的临床充填修复效果，井进行统计学分析。结果：实验组即刻脱敏显效率为90．2％，半年成功率为96．3％，一年成功宰为92．7％；对照组的即刻脱敏显效率、半年成功率、一年成功率分别为76．3％、92．7％，82．5％。2组的即刻脱敏显效率和一年成功率差异有统计学意义。结论：选择合适参数谩置，用脉冲Nd：YAG激光辅助Dyract复合体治疗老年根龋，能减轻术后牙本质敏感症状和提高充填修复的效果，具有临床使用价值。     

脉冲Nd:YAG激光对复合树脂与牙体硬组织密合度的影响

目的 :探讨脉冲 Nd:YAG激光对复合树脂与牙体硬组织之间密合度的影响 ,为临床上解决微渗漏提供参考依据。方法 :收集离体的人前磨牙 60个 ,随机分成 6组。分别选择牙合壁和龈壁作为观察对象 ,按分组分别对洞壁进行表面处理 ,复合树脂充填 ,观察染料的渗入情况。结果 :牙合壁 6个组中 ,不处理组的微渗漏百分数 ( MP)显著高于其它 5组 ( P<0 .0 5 ) ,激光 +酸蚀组的 MP显著低于激光组、酸蚀 +激光组及不处理组( P<0 .0 5 ) ;其余 4组间无显著差异 ( P>0 .0 5 )。龈壁 6个组中 ,无论釉牙骨质界上或下 ,激光组、1 0 -3液组和酸蚀组之间均亦无显著性差异 ( P>0 .0 5 )。对比观察中 ,牙合壁的密合度优于龈壁 ;釉牙骨质界上的龈壁优于釉牙骨质界下的龈壁。结论 :脉冲 Nd:YAG激光照射可在一定程度上改善牙合壁的密合度 ,激光照射后再酸蚀能更好地防止微渗漏。脉冲 Nd:YAG激光照射龈壁 ,不仅能提高洞壁的密合度 ,并能较好地封闭洞壁表面的牙本质小管口 ,减少有害物质对牙髓的不良刺激 ,具有一定的临床应用价值。     

酸蚀处理影响Dyract复合体修复楔状缺损的临床效果的研究

目的：采用改良的USPHS系统评估酸蚀处理对Dyract复合体修复楔状体缺损的临床效果的影响。方法：酸蚀处理后用Dyract修复楔状缺损牙160颗,不酸蚀处理直接用Dyract修复142颗,用改良的USPHS系统对2年后的临床疗效进行评估。结果：实验组的成功率为92．5％,对照组的成功率为80．98％。两组成功率相比差异有显著性,两 组成边缘密合性和边缘着色指标上差异有显著性,实验组优于对照组。结论：在用Dyract复合体充填楔状缺损前用酸蚀处理牙釉质和牙本质可以改善修复体与牙齿的边缘密合程度。     

Er：YAG激光备洞与树脂充填微渗漏的实验研究

目的：评价Er：YAG激光备洞对树脂充填材料边缘微渗漏的影响。方法：选择48颗年轻前磨牙随机分成4组,每组12颗牙,用Er：YAG激光或高速牙钻制备ⅴ类洞。对照组：牙钻备洞＋35%磷酸酸蚀;实验1组：激光备洞＋35%磷酸酸蚀;实验2组：激光备洞＋自酸蚀粘接;实验3组：单纯激光备洞。树脂充填,经冷热循环试验后染色24h,体视显微镜下观察微渗漏,统计学处理数据。结果：龈壁的染料渗透,4组间无统计学差异;壁的染料渗透,以实验3组较明显,与对照组、实验1、2组有统计学差异（P〈0.05）;各组内壁的染料渗透均比龈壁轻,但没有统计学差异。结论：Er：YAG激光备洞,35%磷酸酸蚀或自酸蚀粘接处理可减少洞壁与树脂充填边缘的微渗漏。     

酸蚀处理影响Dyract复合体修复楔状缺损的临床效果的研究

目的 :采用改良的USPHS系统评估酸蚀处理对Dyract复合体修复楔状缺损的临床效果的影响。 方法 :酸蚀处理后用Dyract修复楔状缺损牙 16 0颗 ,不酸蚀处理直接用Dyract修复 142颗 ,用改良的USPHS系统对 2年后的临床疗效进行评估。结果 :实验组的成功率为 92 .5 % ,对照组的成功率为 80 .98%。两组成功率相比差异有显著性 ,两组成边缘密合性和边缘着色指标上差异有显著性 ,实验组优于对照组。结论 :在用Dyract复合体充填楔状缺损前用酸蚀处理牙釉质和牙本质可以改善修复体与牙齿的边缘密合程度     

Marginal integrity of large compomer Class II restorations with cervical margins in dentine

OBJECTIVES: The aim of the present study was to investigate the marginal integrity of total-bond Dyract AP restorations in large Class II restorations with cervical margins in dentine. The efficacy of a new non-rinse conditioner and the effect of beveling the enamel margins were also studied. METHODS: Large MOD cavities with cervical margins located 1mm below the CEJ were prepared in 48 extracted human molars. Six groups (n=8) were filled using a total-bond technique with Spectrum TPH or Dyract AP or a sandwich technique with Dyract in combination with Spectrum TPH. For Dyract AP total-bond restorations, a new non-rinse conditioner was tested vs. a total-etch with 36% phosphoric acid in beveled and butt-joint cavities. After water storage for 21 days and thermocycling (2000x, 5-55 degrees C), replicas were produced for quantitative marginal analysis in the SEM. Afterwards, teeth were immersed in 0.5% basic fuchsin for 24h and dried. Percent dye penetration over the total margin length was analysed in three layers using a sequential grinding technique. Statistical analysis was performed with non-parametric tests and the Bonferroni correction for multiple comparisons at p<0.05. RESULTS: All restoration types showed microleakage. On cervical margins in dentine, Dyract AP restorations showed better marginal adaptation than Spectrum TPH total-bond restorations (marginal openings (MO), median 33.8 vs. 79.6%), but were inferior to Dyract/Spectrum TPH sandwich restorations (MO: 0. 0%). The non-rinse conditioner improved the marginal adaptation of Dyract AP restorations in dentine (MO: 4.7 vs. 38.4%, p=0.0206 for beveled cavities, 12.2 vs. 33.8%, p=0.0238, for butt-joint cavities) and yielded similar results in enamel margins provided that enamel margins were beveled. Beveling of enamel significantly reduced the occurrence of enamel microcracks. CONCLUSIONS: The use of a non-rinse conditioner in combination with Dyract AP may improve the marginal adaptation of Class II restorations compared to composite restorations. The sandwich technique with Dyract results in better marginal adaptation in cervical dentine compared to all other restorative techniques tested in this study. However, microleakage cannot predictably be prevented with the sandwich technique.     

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。     

The effect of an additional flowable compomer layer on microleakage of Class V compomer restorations.

BACKGROUND: Polymerisation shrinkage and the associated stress on composite resins and surrounding structures have been regarded as a major cause of leakage and clinical failures in modern polymer restorations. The purpose of this study was to investigate the effect of an additional flowable compomer layer on the microleakage of Class V dental cavities, which were further filled with a compomer. METHOD: Cavities (32) were prepared in human premolars, conditioned with a non-rinsing agent (Prime & Bond NRC) and treated with the bonding agent (Prime & Bond NT). Sixteen of these cavities were then lined with a layer of flowable compomer (Dyract Flow, approximately 0.5 mm) and further filled with Dyract AP. The other 16 cavities were filled without the flowable compomer. The specimens were thermo-cycled in a 0.5% basic fuchsin solution, sectioned and evaluated for dye penetration using a scoring system of 0 to 4. RESULTS: Lower microleakage values were found at the enamel as well as at the dentine sides when a layer of Dyract Flow was used as a liner. Furthermore, significantly (p < 0.05) lower microleakage was found in enamel than in dentine for both layered and unlayered restorations. CONCLUSION: It can be concluded that a layer of flowable compomer (i.e. Dyract Flow) in a cavity under a compomer may be recommended to improve the marginal seal of a restoration.     

超声波预备根管与Nd：YAG激光照射后根管牙本质的SEM研究

目的：评价超声预备根管及Ｎｄ：ＹＡＧ 激光照射根管壁后,根管内壁的清洁度和管壁牙本质微结构的变化。方法：１２ 个离体成人上前牙分为４ 组制备根管：手用器械、超声根管治疗仪、手用器械＋ Ｎｄ：ＹＡＧ 激光照射、超声波＋ Ｎｄ：ＹＡＧ 激光照射,扫描电镜下观察并照像记录。结果：手用扩锉预备的根管内壁有涂层污染和病理组织残留;超声波预备后根管内壁清洁、涂层消除,牙本质小管口开放;手用器械或超声制备后辅以适当能量激光照射的管内壁牙本质小管口封闭,管间牙本质熔融,并形成空泡状结晶。结论：超声波预备根管可达到理想的清洁效果,但牙本质小管口开放易造成根管术后渗漏。而Ｎｄ：ＹＡＧ 激光照射有利于封闭牙本质小管口,减少根尖孔渗漏,还具有封闭根管内壁死腔的作用。     

Dentine bond strength and microleakage of flowable composite,compomer and glass ionomer cement

Background: To assess in vitro the dentine bond strength and microleakage of three Class V restorations viz. flowable composite, compomer and glass ionomer cement. Methods: Eighteen dentine specimens were prepared and randomly distributed among three groups. Three kinds of restoration materials were each bonded on prepared dentine surfaces in three groups as per the manufacturers’ instructions. Group Aelite: Tyrian SPE (a no‐rinse, self‐priming etchant) + One Step Plus (an universal dental adhesive) + Aeliteflo (a flowable composite); Group Dyract: Prime & Bond NT (a no‐rinse, self‐priming dental adhesive) + Dyract AP (a compomer); Group GlasIonomer: GlasIonomer Type II (a self‐cured restorative glass ionomer). Fifteen dentine/restoration microtensile bond test specimens were prepared from each group and were subjected to microtensile bond strength testing. The bond interfaces were observed morphologically using a scanning electron microscope (SEM). Twenty‐four cervical cavities of 4.0 mm mesiodistal length, 2.0 mm occlusogingival height and 1.5 mm depth were prepared at the cemento‐enamel junction (CEJ) on both buccal and lingual surfaces of each tooth. The cavities were each filled with flowable composite (Group Aelite), compomer (Group Dyract) and glass ionomer cement (Group GlasIonomer) using the same material and methods as for the microtensile bond tests. Microleakage of each restoration was evaluated by the ratio of the length of methylene blue penetration along the tooth‐restoration interface and the total length of the dentine cavity wall on the cut surface. Results: One‐way ANOVA and least significant difference (LSD) tests revealed statistically significant differences among the dentine bond strength for Group Aelite (28.4 MPa), Group Dyract (15.1 MPa) and Group GlasIonomer (2.5 MPa). SEM images showed intimate adaptation in the restoration/dentine interfaces of Group Aelite and Group Dyract. All of the systems tested in this study presented microleakage. However, both Group Aelite (0.808) and Group Dyract (0.863) had significantly less microleakage than Group GlasIonomer (0.964). There were no statistically significant microleakage differences between Group Aelite and Group Dyract, and no statistically significant microleakage differences between the occlusal margin and gingival margin. Conclusions: None of the systems tested in this study completely eliminated microleakage. However, both the flowable composite and compomer provided stronger dentine bond strengths and better margin sealing than the conventional glass ionomer cement. Occlusal forces exerted the same effects on microleakage of the occlusal margin and gingival margin in cervical cavities.     

Effects of Nd: YAG laser irradiation on the adaptation of composite resins to root dentin

One of the most important goals of the restoration of endodontically treated teeth with a composite resin post system is to achieve good adaptation of the composite material to dentin walls to prevent microleakage apically and coronally. In post core systems, to avoid microleakage between the dentin wall and resin material, laser irradiation may seem to be an alternative therapy for increasing adaptation quality. The aim of this study was to investigate the adaptation of a packable composite resin to lased root canal dentin when it was used as post material. Forty-five freshly extracted human teeth were selected and post spaces were prepared. The teeth were divided into three groups. In group 1 the dentin of the post spaces were etched with 35% phosphoric acid, in group 2 the dentin surfaces were irradiated with an Nd: YAG laser, and in group 3 the dentin surfaces were initially treated with the laser and then etched. The teeth of all groups were obturated with a bonding agent and composite. The groups were divided into two subgroups: a group for the scanning electron microscope (SEM) study and a group for the microleakage study. The lased group showed poor adaptation and more microleakage was detected (p<0.05; variance analysis). The laser beam and acid-etching showed no advantage compared to the acid-etching alone (p>0.05). The Nd: YAG laser irradiation adversely affects adhesion to dentin for using composite resin as a post material and does not constitute an alternative to acid-etching.     

Microleakage of class V resin composite restorations after bur, air-abrasion or Er:YAG laser preparation

This in vitro study compared the microleakage of Class V resin composite restorations placed in cavities prepared with a high-speed dental bur, air-abrasion or Er:YAG laser. Twenty sound extracted human third molars were selected and randomly assigned to four equal Groups (n=10): Group I, cavities were cut by dental drill at high-speed; Group II, aluminum oxide air-abrasion was used for cavity preparation, and in Groups III and IV, cavities were prepared by Er:YAG laser. Following cavity preparation, Groups I and II were acid-etched, Group III was treated only by Er:YAG laser and Group IV was conditioned by Er:YAG laser followed by acid-etching. Cavities were restored (Single Bond + Z-100) and the teeth stored for seven days in distilled water. Then, the restorations were polished and the specimens thermocycled, immersed in a 0.2% Rhodamine solution, sectioned and analyzed for leakage at the occlusal (enamel) and cervical (dentin/cementum) interfaces using an optical microscope connected to a video camera. The images were digitized and software was utilized for microleakage assessment. Upon analyzing the results, statistically significant differences (p<0.01) between the occlusal and cervical regions for all groups was observed, and, as a rule, there was better marginal sealing at the enamel margins. The highest degree of infiltration was observed for cavities prepared and treated exclusively by Er:YAG (Group III). The other experimental groups showed statistical similarities in the amount of marginal leakage at the enamel margins. However, at the cervical margins, there was a significant difference (p<0.05) between Group I and the remaining groups. None of the techniques completely eliminated marginal microleakage at the dentin/ cementum margins.     

四种充填材料修复根面龋的微渗漏研究

目的比较四种充填材料修复根面龋的充填体边缘微渗漏情况。方法将制备洞型后的44颗离体牙随机分为4组,每组11个牙,备洞后分别采用复合体(3M F2000,简称Co组)、粘结银汞合金(黏结剂为3M Adper Prompt,简称Ad组)、银汞合金(杭州银亚新高铜球形银汞胶囊,简称Am组)和玻璃离子(3M Ketac,简称Ke组)材料充填,进行染料渗透试验。在Olympus GM型暗视野实体显微镜下观察并测量次甲基兰渗漏深入的部位,取根面龋离体牙20个,采用4种临床常用材料分别充填后在扫描电镜下观察充填材料和牙齿密合度并拍摄照片。结果使用复合体充填产生的微渗漏最小(0．03-0．76mm),其次为黏结银汞(0．44- 0．82mm)和银汞(0．89-1．59mm),玻璃离子产生的微渗漏最大(1．73-2．58mm)。结论复合体充填材料能够更好地预防继发龋和充填物脱落。     

The sealing ability of an epoxy resin root canal sealer after Nd:YAG laser irradiation of the root canal

AIM: To evaluate ex vivo the effect of Nd:YAG laser irradiation with and without black ink on instrumented root canal walls, and the degree of both coronal and apical microleakage of filled root canals. METHODOLOGY: Seventy-two single-rooted teeth were instrumented up to a size 40 K-file, and then divided into six groups of 10 teeth: groups 1 and 4 remained unlased and acted as control groups, groups 2 and 5 were treated with a Nd:YAG laser (Fidelis Plus, Herzele, Belgium), groups 3 and 6 were treated with a laser and black ink; the remaining 12 teeth served as positive and negative controls. The laser was operated at 1.5 W, 15 Hz, four times for 5 s with a 20-s interval. Groups 4-6 were filled using cold lateral condensation of gutta-percha and AH26. After storage in water for 48 h at 37 degrees C, through-and-through leakage (L in microL day-1) was measured for 48 h under a pressure of 1.2 atm using a fluid transport model and recorded as L=0 (L1), 010 (L3). After the assessment of leakage with the fluid transport model, the teeth were immersed in rhodamine B solution for 48 h at 37 degrees C. Apical and coronal dye leakage was scored after longitudinal splitting of these teeth. All teeth of groups 1-3 were split longitudinally and observed under SEM for evaluation of remaining smear layer. RESULTS: Through-and-through leakage was only observed in the group lased with black ink (two samples-L2). Apical and coronal dye leakage was observed in all groups; there were no statistically significant differences amongst the three experimental groups. The through-and-through leakage, measured with the fluid transport model in two teeth of group 6, was confirmed in the dye leakage test (rhodamine B dye was observed along the total length of the root filling). There was evidence of melted and ablated root canal dentine in the laser-treated groups. These findings were more obvious in root canals lased in association with black ink. All apical foramina in the lased group remained patent. CONCLUSIONS: Nd:YAG laser irradiation with black ink increased the amount of melted and ablated dentine areas compared with that without black ink. Nd:YAG lasing in association with black ink did not result in a reduction of either coronal or apical microleakage in root filled teeth.