The effect of acid primer or conventional acid etching on microleakage in a photoactivated sealant

PURPOSE: The purpose of this study was to examine differences in microleakage in extracted human teeth when placing sealants using conventional acid etching or an acidic primer resin. METHODS: Three experimental groupings were used: group 1--conventional acid etching with placement of light-cured sealant; group 2--application of acidic primer resin (Prompt-L-Pop) and light curing, followed by sealant placement; group 3--similar to group 2, but acidic primer and sealant were photocured after placement of sealant. Teeth were thermocycled, stained, sectioned and examined for marginal microleakage. RESULTS: In group 1, 94% of the enamel-sealant interfaces were free of microleakage. For groups 2 and 3, only 28% showed no leakage, with most leakage occurring at both margin and base areas. Nonparametric data analysis indicated acid etching demonstrated significantly lower microleakage than either treatment using the acidic primer resin (P<.001) and that leakage scores in the acidic primer groups were identical (P=.4011). CONCLUSIONS: Use of this specific acidic resin primer in lieu of conventional acid etching (whether cured prior to or subsequent to sealant placement) demonstrated greater incidence of microleakage and would not be advocated over traditional etching procedures.     

In vitro evaluation of two microleakage detection tests.

Two microleakage detection tests were evaluated to compare their capabilities for revealing the extent of leakage at the interface between amalgam restorations and tooth structure. Class V cavities were prepared in the buccal surfaces of extracted human canine and premolar teeth and were treated in one of the following ways: no liner or varnish, a copal varnish, or an adhesive resin liner. The cavities were restored with a high-copper single composition spherical amalgam alloy and the specimens thermally cycled. Following storage for 6 months, the teeth were exposed to separate solutions of 45Ca and an ultraviolet fluorescing dye. The teeth were hemisected longitudinally and leakage was evaluated by determining the degree of penetration of the two tracers at the occlusal and gingival margins. Statistical analysis revealed a significant difference between the two leakage techniques (P less than 0.05). The radioisotope test generally indicated a greater degree of leakage than did the ultraviolet dye test.     

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 study of microleakage of fissure sealant with different previous treatments

The purpose of this work was to evaluate microleakeage of a sealant after using three different techniques for conditioning the surface to be sealed. Twenty-four caries-free upper and lower premolars were used, which were preserved in distilled water at room temperature. The structural faults were enlarged using a cylindrical conical diamond (ISO 007). Teeth were randomly assigned into three groups of eight. Group I (control) was conditioned with 37% phosphoric acid (Vivadent) for 15 seconds after which the sealant Helioseal F (Vivadent) was applied and cured for 40 seconds. Group II was conditioned in the same way, after which one-step adhesive Te-econom (Vivadent) and the sealant were applied. Group III was conditioned using a self-etching adhesive, Go (SDI), after which the sealant was applied. Adhesive was applied according to the manufacturer's instructions. The samples were thermocycled for 300 cycles between 5 degrees and 55 degreesC and immersed in a 2% methylene blue solution for 48 hs. at standardized temperature of 37 degreesC +/- 1 degree. Then they were rinsed with tap water and ground longitudinally in V-P direction with silica carbide rotatory disks of decreasing grit. The amount of leakage was evaluated under stereoscopic microscope at 40X magnification. The longitudinal penetration of dye into the tooth-sealant interface was scored on a scale of 0 to 3. The results were analyzed by a Kruskal-Wallis non-parametric test. In Group II, 100% of the samples showed low (50%) or no (50%) leakage. Both the other groups had a higher percentage of specimens with high leakage (scores 2 and 3) (P = 0.000). Group II had the best performance, with significant differences (P = 0.0028) compared to the other experimental groups. Marginal leakage was lowest when the tooth was conditioned with phosphoric acid and subsequent application of an adhesive, prior to sealant.     

In vitro microleakage of dentin adhesives.

This in vitro study measured the microleakage of current dentin bonding agents and glass-ionomer bases. Freshly extracted human molars were prepared to a flat surface, and dentin adhesives and composite resins were applied in a plastic matrix. Samples were stored in water at 37 degrees C, thermocycled, stained with AgNO3, embedded in epoxy resin, and sectioned for evaluation of stain penetration at the composite resin/tooth interface. The reliability index of the dentin adhesives varied significantly between materials. The enamel control had essentially no microleakage, and the aluminum oxalate dentin adhesive on dentin had significantly less microleakage than other dentin adhesives tested. Present dentin adhesives were unable to prevent, but may reduce, microleakage.     

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目的评价自制洗必泰凝胶对粪肠球菌的抑菌效果。方法于2011年9月至2012年3月在辽宁省疾病控制中心微生物实验室采用纸片扩散法药敏实验测定生理盐水（A组）、Vitepex（B组）、2％洗必泰溶液（c组）和洗必泰凝胶（D组）对粪肠球菌形成的抑菌环直径并进行统计学分析。结果C组和D组的抑菌环直径明显大于B组,差异有统计学意义（p〈0．01）;C组和D组抑菌环直径的差异无统计学意义（P〉0．05）;4组组内各时间点抑菌环直径差异均无统计学意义（P〉0．05）。结论洗必泰凝胶是根管再治疗的理想消毒药物。     

In vitro evaluation of microleakage of a flowable composite in Class V restorations

The aim of this study was to evaluate microleakage around class V restorations using a flowable composite compared to a hybrid composite. Forty class V cavities were prepared on buccal and lingual surfaces of 20 human teeth, with occlusal and cervical margins at the enamel and cementum/dentin levels, respectively. Specimens were divided into 2 groups with 10 samples each. Group 1: buccal cavities received Paama 2 (conventional bonding agent) + Wave (flowable composite); lingual cavities were restored with Paama 2 + Glacier (hybrid composite). Group 2: buccal cavities received Optibond Solo (self-priming bonding agent) + Wave; lingual cavities were restored with Optibond Solo + Glacier. After being stored in distilled water and finished, the teeth were thermocycled, immersed in a 50% silver nitrate solution and embedded in resin. They were sectioned and the depth of tracer penetration was scored. The results were analyzed using Kruskal-Wallis and Wilcoxon tests. The restorations with flowable composite and those with hybrid composite from the same group showed similar results of microleakage for both occlusal and cervical margins. Optibond Solo improved the sealing of the restorations when compared with Paama 2 (p < 0.01). None of the restorative materials completely sealed the tooth/restoration interface at the cervical margins.     

Degree of microleakage of a self-etch sealant

The purpose of this study was to compare the microleakage of a new self-etch sealant (Enamel Loc), with and without acid etching, to a traditional sealant (UltraSeal XT Plus) with acid etching in occlusal fissures. The self-etch sealant had significantly more microleakage than the traditional sealant or the self-etch sealant with acid-etching of the enamel.     

In vitro evaluation of microleakage of different materials used as pit-and-fissure sealants

The aim of this study was to evaluate in vitro the marginal microleakage of different materials used as pit-and-fissure sealants (Delton, Filtek Flow, Dyract Flow and Vitremer). Fifty-six extracted sound human third molars were randomly assigned to 4 groups (n=14). After sealant placement, the teeth were thermocycled (500 cycles; 5 degrees C, 37 degrees C and 55 degrees C), isolated, immersed in 2% buffered methylene blue dye for 4 h, included in acrylic resin and sectioned longitudinally in a buccolingual direction. The sections were analyzed for leakage using an stereomicroscope. A 4-criteria ranked scale was used to score dye penetration. All materials exhibited dye penetration to some extension and no statistically significant difference was observed among the groups (p>0.05). In conclusion, the findings of this study showed that a flowable composite resin, a flowable compomer and resin-modified glass ionomer placed on occlusal pits and fissures had similar marginal sealing as the unfilled self-cured resin-based sealant.     

In vitro microleakage of a fissure sealant polymerized by either a quartz tungsten halogen curing light or a plasma arc curing light

BACKGROUND: The benefits of using plasma arc curing lights with their shorter curing times in the management of children are potentially great, provided there are no adverse effects. OBJECTIVE: The aim of this study was to investigate whether the microleakage of a resin-based sealant is influenced by polymerization with either a conventional quartz tungsten halogen or a plasma arc curing light. DESIGN: This study took the form of an in vitro randomized control trial. Seventy extracted human first and second permanent premolars and molars were randomly allocated into two groups. Their occlusal surfaces were sealed with a light-cured fissure sealant using either a quartz tungsten halogen curing light or a plasma arc curing light. The teeth were then sectioned, resulting in four surfaces per tooth, which were examined for microleakage under x 15 magnification with a light microscope. The principal unit of analysis was the tooth (worst section score) and not the section microleakage score. RESULTS: No statistical significant difference in microleakage scoring between the two groups was demonstrated. CONCLUSION: This study found no difference in the degree of microleakage of fissure sealants polymerized by either light source.     

The effect of bonding agents on the microleakage of sealant following contamination with saliva

Aims : An issue of concern in dentistry is the inadequacy of adhesion and proper sealing following restoration of a tooth, which can lead to marginal leakage. The aim of this study was to evaluate the effect of a bonding agent on the microleakage of a sealant material following contamination with saliva. Materials and Methods : In this experimental research, 48 sound premolars were divided into two groups. The first group received sealant without bonding and the other group was given sealant with bonding. After prophylaxis, the occlusal surfaces were etched with 37% phosphoric acid gel and the teeth were then placed in fresh human saliva for l0 s. Following this, in the first group fissure sealant (Kerr) was applied directly and cured; for the second group sealant was placed and cured after bonding (Single Bond; 3M). All samples were thermocycled (500 cycles; between 5 degrees C and 55 degrees C; dwell time of 30 s). Silver nitrate was used as the leakage tracer. The teeth were sectioned. Microleakage evaluation was made by stereomicroscope at 40x magnification and the results were evaluated with the Mann-Whitney U test. Results : In the group that received sealant without bonding extensive microleakage was seen; placement of sealant with bonding significantly reduced microleakage. Conclusion : In the presence of contamination with saliva, use of bonding under the fissure sealant can reduce microleakage.     

In vitro microleakage of composite restorations after nonvital bleaching.

OBJECTIVE: After bleaching treatment, esthetic restorations often need to be replaced due to color changes. Some papers have shown alterations in the bond of adhesive restorations to bleached teeth. The purpose of this study was to evaluate tooth and resin composite adhesion when submitted to nonvital dental bleaching. METHOD AND MATERIALS: One hundred and twenty bovine teeth were assigned to 3 groups (n = 40); paste of sodium perborate and water; 37% carbamide peroxide gel; and no bleaching (control). After 3 weeks of continuous bleaching treatment, standardized Class V cavities were prepared at the cementoenamel junction and restored with Single Bond adhesive system and Z100 resin composite. The samples were thermocycled 1,500 times (5 +/- 1/55 +/- 1 degrees C) with a 1-minute dwell time. Then, they were immersed in a 2% methylene blue solution (pH 7) for 4 hours, sectioned, and analyzed by stereomicroscopy. Microleakage analyses were done, using scores from 0 to 4, considering leakage on the incisal wall (enamel) and the cervical wall (dentin). Data were analyzed by Kruskal-Wallis and Mann-Whitney tests (alpha = 0.05). RESULTS: The results showed that sodium perborate and carbamide peroxide gel significantly increase the microleakage in Class V resin composite restorations to dentin but not to enamel margins. CONCLUSION: The risk of microleakage in dentin margins is increased soon after bleaching treatment.     

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。     

Marginal microleakage of a sealant applied to permanent enamel: evaluation of 3 application protocols

PURPOSE: The purpose of this in vitro study was to investigate and compare the microleakage-occurring after the placement of a light-curing sealant-to unground permanent enamel which had been previously conditioned using 3 different application protocols. METHODS: Sixty-three molars were randomly distributed in 3 different groups according to the application protocol of the sealant: (1) conditioning of the enamel with 38% phosphoric acid (group 1); (2) conditioning with phosphoric acid and single-bottle dentin bonding agent (group 2); or (3) conditioning with a self-etching adhesive (group 3). Samples were: (1) thermocycled; (2) stained; (3) sectioned; and (4) examined for marginal microleakage. RESULTS: No dye penetration was noted for 25%, 59%, and 40% of cases for groups 1, 2, and 3, respectively. CONCLUSIONS: Placement of a bonding agent layer prior to the sealant allows significantly less microleakage than the traditional conditioning of enamel with phosphoric acid alone. The self-etching adhesive used here seems to be an attractive alternative to the acid-etch and adhesive technique for sealant application in young children, since it would simplify the procedure. Clinical trials should be performed to assess the performance of these products before definitive conclusions can be formulated.     

In vitro microleakage of glass-ionomer composite resin hybrid materials.

The purpose of this study was to evaluate the microleakage of six glass-ionomer composite resin hybrid materials compared with a glass-ionomer cement and a composite resin. Standardized class 5 dentin cavities were prepared on root surfaces of 240 extracted human teeth that were randomly assigned to eight groups and restored using the following restorative systems: (I) Vitremer, (II) Compoglass, (III) Photac-Fil Aplicap, (IV) Variglass, (V) Dyract, (VI) Fuji II LC, (VII) Ketac-Fil Aplicap, and (VIII) Z100. The teeth were thermocycled, placed in a 2% methylene blue solution, and sectioned with diamond disks. Dye penetration was scored on a scale of 0-3. Results showed no significant differences among groups VIII, IV, I, V, VI, III, and II. There were also no significant differences among groups VI, III, II, and VII.     

In vitro accelerated aging of composites and a sealant

The in vitro accelerated aging of conventional and microfilled composite restorative materials and a sealant was studied. Volume loss/surface area ranged from 2.0 x 10(-3) mm3/mm2 for I to 7.3 x 10(-3) mm3/mm2 for SF after 900 h of aging. Surface morphology of the conventional composites was characterized by crazing and exposure of filler particles. The surfaces of the microfilled composites also showed crazing. The surface morphology of the sealant appeared unchanged. Comparisons of infrared ATR spectra between zero and 900 h of aging showed that slight chemical changes occurred at the surface of AR but not SF.     

窝沟封闭剂对托槽周围微渗漏影响的实验研究

目的 研究应用窝沟封闭剂封闭后金属托槽周围微渗漏的改变，为临床上应用窝沟封闭剂预防托槽周围釉质脱矿提供理论参考。方法 选择健康双尖牙72颗，随机分成3组，每组24颗，A组：37％磷酸酸蚀，京津釉质粘结剂粘结金属托槽。B组：37％磷酸酸蚀，3M Transbond光固化粘结剂粘结。C组：自酸蚀系统＋3M光固化粘结剂。再将每组的24颗牙随机分成实验组（A2、B2、C2）和对照组（A1、B1、C1），每组12颗，其中A2、B2、C2组用窝沟封闭剂涂布托槽周围，A1、B1、C1组不涂布窝沟封闭剂。所有样本进行冷热循环共500次，然后置于1％亚甲蓝溶液中浸泡染色24小时。将样本沿牙体长轴纵行切开，25倍立体显微镜下测量染料渗入最深点到托槽边缘的距离作为微渗漏的测量值，并对测量值进行方差分析和两两比较。结果 应用窝沟封闭剂与不用窝沟封闭剂组微渗漏的比较结果：A1组：A2组差别有高度统计学意义；B1组：B2组差别有统计学意义；C1组：C2组差别无统计学意义。结论 窝沟封闭剂能够明显减少磷酸酸蚀组的微渗漏而对自酸蚀组的作用不明显。     

In vitro microleakage of adhesive-sealed dentin with lactic acid and saliva exposure: a radio-isotope analysis

OBJECTIVES: The aim of this study was to evaluate the dentin-protective potential of two dentin-bonding systems (Syntac and Clearfil SE Bond) on artificial saliva and lactic acid exposure. METHODS: Radiochemical analysis in combination with polarization-microscopy was used in the current study. Different applications in MOD preparations in irradiated human molars were compared. Untreated cavities and cavities covered with flowable resin served as controls. Forty-eight specimens were immersed in artificial saliva (pH 7.5), 48 in lactic acid (pH 4). Activity of (32)P was measured between days 1 and 21 and loss of mineralized tissue was estimated. RESULTS: In lactic acid, cavities sealed with single bond, double bond or bond plus cavity sealer application resulted in significantly lower mineralized tissue loss compared to negative controls (p < 0.05). Upon both saliva and lactic acid exposure, bonding plus sealer application proved to be the most protective treatment (p < 0.05). CONCLUSIONS: Based on these in vitro findings it may be advisable to use a filled cavity sealer or a flowable resin to protect dentin from demineralization. The radiochemical analysis appeared to be valuable in evaluating the protective potential of bonding agents against dentin demineralization.