自制透明硅胶导板在前牙树脂嵌体修复中的微渗漏研究

目的:研究自制透明硅橡胶导板在前牙微创美学修复中对树脂嵌体与牙体之间微渗漏的影响,以期为临床修复方法提供更丰富的选择及理论依据。方法:选择30颗离体前牙作为实验对象,按嵌体制作标准预备成Ⅳ类牙体缺损洞型,随机分为3组:A组(自制透明硅橡胶导板制作树脂嵌体);B组(传统硅橡胶导板制作树脂嵌体);C组为对照组(全酸蚀直接法树脂充填),其中A组嵌体借助透明硅橡胶导板辅助就位粘接,所有标本经冷热循环和染色处理后,体式显微镜下观察试件的微渗漏情况。结果:3组均产生了微渗漏,A、B两组的微渗漏值均较C组小(P＜0.05),有统计学意义。A组的微渗漏值略小于B组,但差异无统计学意义。结论:自制透明硅橡胶导板能够减少修复体与牙体之间的微渗漏。     

Influence of different restorative techniques on marginal seal of class II composite restorations

Objective

To evaluate the gingival marginal seal in class II composite restorations using different restorative techniques.

Material and Methods

Class II box cavities were prepared in both proximal faces of 32 sound human third molars with gingival margins located in either enamel or dentin/cementum. Restorations were performed as follows: G1 (control): composite, conventional light curing technique; G2: composite, soft-start technique; G3: amalgam/composite association (amalcomp); and G4: resin-modified glass ionomer cement/ composite, open sandwich technique. The restored specimens were thermocycled. Epoxy resin replicas were made and coated for scanning electron microscopy examination. For microleakage evaluation, teeth were coated with nail polish and immersed in dye solution. Teeth were cut in 3 slices and dye penetration was recorded (mm), digitized and analyzed with Image Tool software. Microleakage data were analyzed statistically by non-parametric Kruskal-Wallis and Mann-Whitney tests.

Results

Leakage in enamel was lower than in dentin (p<0.001). G2 exhibited the lowest leakage values (p<0.05) in enamel margins, with no differences between the other groups. In dentin margins, groups G1 and G2 had similar behavior and both showed less leakage (p<0.05) than groups G3 and G4. SEM micrographs revealed different marginal adaptation patterns for the different techniques and for the different substrates.

Conclusion

The soft-start technique showed no leakage in enamel margins and produced similar values to those of the conventional (control) technique for dentin margins.     

玻璃离子水门汀边缘封闭性的研究

玻璃离子水门汀作为齿科充填和黏结材料,以其优良的性能在口腔临床得到广泛应用。随着材料学的发展,出现了更适于临床应用的改良型玻璃离子水门汀。边缘封闭性是评价修复充填材料的重要标准,其好坏影响了黏结修复的稳定性。目前认为,改良型玻璃离子水门汀具有良好的边缘封闭性和更少的微渗漏,可以应用于口腔黏结修复。现就传统型和改良型玻璃离子水门汀及其在不同口腔黏结修复应用中的边缘封闭性进行综述。     

SonicFill系统对II类洞充填后微渗漏影响的研究

目的:探讨树脂充填系统SonicFill对Ⅱ类洞树脂充填后微渗漏的影响。方法:收集口腔颌面外科门诊拔除的各类恒磨牙15例,每例样本中2个Ⅱ类洞随机分为实验组、对照组。实验组:用SonicFill超声树脂充填系统充填窝洞;对照组:用HerculitePrécis纳米树脂斜向分层充填窝洞。500次冷热循环实验后保存于0.5%碱性品红溶液中,24 h后沿近远中向剖开,体视显微镜观察染色情况并记录评分(0-3);扫描电镜测量树脂与牙体组织间微缝隙宽度。轴壁和龈壁染料渗入深度采用Mann-Whitney U检验进行评估;采用两个样本t检验比较微缝隙的宽度,检验水准α设为0.05。结果:染料渗入评分结果表明:SonicFill组与对照组相比,染料渗入的深度明显不同,差异具有统计学意义(P＜0.05);各组内轴壁染料渗入深度明显少于龈壁(P＜0.05)。扫描电镜2000倍视野下微缝隙宽度测量结果表明:SonicFill组与对照组的微缝隙宽度存在明显不同,差异具有统计学意义(P＜0.01);各组内轴壁与龈壁相比,轴壁微缝隙的宽度明显小于龈壁(P＜0.01)。结论:SonicFill超声树脂充填系统能够有效减少Ⅱ类洞树脂充填术后微渗漏的发生。轴壁与龈壁相比,轴壁微渗漏明显小于龈壁。     

万能金相显微镜在牙体充填材料微渗漏研究中的应用

目的:定量观测玻璃离子在人离体牙充填后的微渗漏情况,比较传统型玻璃离子水门汀和树脂改性玻璃离子水门汀的边缘封闭性;试用万能金相显微镜为观测仪器,评价其应用效果.方法:选取新鲜无龋前磨牙,备洞,充填玻璃离子水门汀,37℃水浴条件下置于1%甲基蓝溶液浸染,万能金相显微镜下测量染液渗入深度,定量评价微渗漏程度.结果:在分别充填传统型玻璃离子水门汀和树脂改性玻璃离子水门汀的情况下,万能金相显微镜下测得的渗漏值分别为(27.11±6.23)μm和(26.92±5.02)μm,P>0.05,二者比较差异无统计学意义.结论:传统型玻璃离子水门汀和树脂改性玻璃离子水门汀充填后的边缘封闭性无显著差异;万能金相显微镜可用于牙体充填材料微渗漏的观测.     

两种玻璃离子水门汀边缘封闭性的体外比较

目的:比较两种玻璃离子水门汀体外充填后的边缘微渗漏现象,为GCFuji-Ⅱ型玻璃离子水门汀材料在临床的使用提供一定的参考和资料。方法:选择健康离体前磨牙80颗,随机分为2组,即实验组和对照组,分别进行微渗漏实验和密合度实验。每个样本的颊面近龈1/3处制备3mm×3mm×2mm的V类洞,实验组充填GCFuji-Ⅱ型玻璃离子水门汀,对照组充填上海青浦尼康齿科器械厂生产玻璃离子水门汀,采用染料渗透实验,用光学显微镜观测染料渗入牙齿的程度及扫描电子显微镜观测充填体边缘的密合状况。结果:染料渗透实验表明两组充填物边缘均有不同程度染料渗入,但GCFuji-Ⅱ型玻璃离子水门汀少于对照组玻璃离子水门汀;扫描电镜观测显示两组充填物与牙体的间隙宽度平均值分别为:GCFuji-Ⅱ型玻璃离子(13.48±1.089)μm,对照组玻璃离子水门汀(39.54±5.82)μm,两组相比有统计学差异(P<0.01)。结论:GCFuji-Ⅱ型玻璃离子水门汀边缘封闭性优于对照组玻璃离子水门汀。     

The accuracy of electrical method for microleakage evaluation by a three-dimensional analysis

OBJECTIVES: This in vitro study aimed to investigate the accuracy of an electrical method for the evaluation of microleakage by a three-dimensional analysis of dye penetration. METHODS: Coronal cavities were prepared on buccal, palatal or lingual surfaces in extracted human molars. The cavities were then filled with resin composites and were subjected to 10,000 load cycles (425g). Before cavity preparation and after load cycling, physiological saline was applied and wiped off, and the change in conductance was measured across the margin of the restoration in each specimen. After dye penetration, the specimens were reduced by 100 microm in a direction parallel to the cavity floor, from the surface of the restoration to the cavity floor. The sequence of reducing the sections by 100 microm and image taking was repeated. Three-dimensional images of dye penetration were made and the proportions of the interface showing penetration were calculated. RESULTS: Pearson's correlation coefficients between changes in conductance and the surface area of dye penetration, between these and the rate of dye penetration, and between these and the depth of dye penetration were 0.932, 0.920 and 0.732, respectively. The correlations were significant (p<0.05). CONCLUSIONS: The results of this electrical method for microleakage evaluation showed stronger correlations with the three-dimensional amount of marginal leakage (surface area of dye penetration and rate of dye penetration) than the two-dimensional amount (depth of dye penetration).     

不同预处理方法对龋齿牙本质微渗漏和粘结效果的影响

目的:观察不同预处理方法对龋齿牙本质微渗漏和粘结效果的影响,为临床应用提供依据.方法:收集2020年1月-12月南昌大学附属口腔医院口腔颌面外科门诊拔除的离体有龋牙60颗,沿前体牙长轴正中磨为两半,获得120个牙样本.根据预处理方式不同分为A组(2％NaClO)、B组(2％氯己定)和C组(75％乙醇),比较3组牙体粘结...     

An in vitro evaluation of microleakage of resin based composites bonded to chlorhexidine-pretreated dentin by different protocols of a universal adhesive system

PurposeThis study compared microleakage of different resin based composite (RBC) materials bonded to dentin, after chlorhexidine (CHX) application, by different adhesion protocols of a universal adhesive system.MethodsClass V cavities were prepared on the buccal and lingual surfaces of 40 premolar teeth. The “etch-and-rinse” technique of a universal bond adhesive system (Single Bond Universal Adhesive) was used on buccal preparations, while the “self-etch” protocol was used on the lingual surfaces. Two RBCs, one bulk fill (Filtek Bulk Fill [FBF]) and one conventional (Filtek Z350 XT [Z350XT]), were used. Teeth were divided into two groups of 20 teeth each, 10 per each RBC (n = 10): (1) control; and (2) pretreatment with 2% CHX. For FBF groups, teeth were restored with a single increment; however, for Z350XT, a layering technique was used. Teeth were aged by thermo-cycling and prepared for microleakage testing. Dye penetration was evaluated and scored from 0 to 4. Data were analyzed at a significance level of P < 0.05.ResultsThe highest microleakage mean scores were found in the control group of the etched margins for both RBCs (2.80 ± 1.033 FBF and 2.10 ± 1.370 Z350XT). The CHX-pretreated group showed significantly lower microleakage than the control for FBF only (P = 0.008). No significant difference was found between groups for the “self-etch” protocol (χ² = 0.884, P = 0.08). No significant differences were found between FBF and Z350XT in all study groups (P > 0.2).ConclusionsWhen the “self-etch” protocol of the universal adhesive system was used, dentin microleakage was not affected by CHX-pretreatment when teeth were restored with bulk fill or conventional RBCs. In the “etch-and-rinse” protocol, CHX application improved the marginal seal before restoration with bulk fill material. However, in the absence of CHX, the “etch-and-rinse” protocol negatively affected marginal integrity.     

不同黏结剂和黏结方法对托槽周围微渗漏的影响

目的：观察、比较不同黏结材料、不同酸蚀方法黏结正畸金属托槽后的微渗漏情况。方法：选择因正畸拔除的健康前磨牙36颗,随机分成3组,每组12颗。A组：37％磷酸酸蚀,京津釉质黏结剂黏结金属托槽;B组：37％磷酸酸蚀．3M Transbond光固化黏结剂黏结;C组：自酸蚀系统＋3M Transbond光固化黏结剂。所有样本进行冷热循环,1％亚甲蓝溶液染色后．立体显微镜下观察并测量各组托槽周围微渗漏情况。用SPSS 11．0统计软件对试验结果先进行方差齐性检验,F检验有统计学意义,进一步用Q检验进行组间比较。结果：①3组间微渗漏差别有统计学意义（F=22．462．P〈0．01）,两两比较发现,A组与B组的微渗漏差别无统计学意义（P〉0．05）;而A、B组均较C组的微渗漏小,差别有显著性（P〈0．05）。②3组龈方微渗漏均大于[牙合]方,差别有统计学意义（分别为P〈0．05、P〈0．01、P〈0．01）。结论：①微渗漏的大小与黏结剂的种类无明显关系。②不同酸蚀方法间的微渗漏差别明显,自酸蚀组较磷酸酸蚀组的微渗漏明显大。③同种材料、同种酸蚀方法,托槽龈方微渗漏明显大于[牙合]方。