Assessing microleakage at the junction between amalgam and composite resin: a new method in vitro.

A new dye-diffusion test method was utilized to evaluate the microleakage between amalgam and composite resin. An amalgam cylinder was made to which a base of composite was added. The effects of several factors upon the microleakage were investigated. The test results indicated less microleakage when bonding agent was applied directly to the roughened amalgam prior to placement of composite resin. The most microleakage was found when roughened amalgam surface was acid-etched before placement of bonding agent and composite resin.     

Effect of flexural load cycling on microleakage of extended root caries restorations

This study evaluated the microleakage of resin-modified glass ionomer, flowable compomer and flowable resin composite restorations on a Class V cavity of simulated advanced root caries under a flexural load cycling condition. Thirty-six non-carious human maxillary premolars were mounted in cylindrical acrylic resin molds. The cavities were prepared in the proximal root surface, from the middle of the buccal surface to the middle of the lingual surface, approximately 1 mm below the cemento-enamel junction, 2 mm axial width and 1.2 mm in depth. The teeth were randomly assigned to one of three groups with 12 teeth in each group: Group 1: Cavity conditioner and Fuji II LC (GC America), Group 2: Prime & Bond NT and Dyract Flow (Caulk-Dentsply), Group 3: Excite and Tetric flow (Ivoclar/Vivadent). Specimens were settled laterally on a fatigue-testing machine that was adjusted to deliver a force of 60N. The specimens were load cycled at 1 Hz for 5000 cycles, placed in a staining solution and sectioned to evaluate microleakage penetration. Results indicate that the coronal and gingival margins showed significant microleakage differences among the three restorations (p<0.05). At the coronal margin, there was no significant difference between Groups 2 and 3. At the gingival margin, there was no significant difference between Groups 1 and 2. It was concluded that the marginal sealing ability of a flowable resin composite under a flexural cycling load was better than in other selected materials and that flowable resin composite with dentin adhesive was a desirable alternative for root caries restorations extended to the proximal surface.     

Effect of eccentric load cycling on microleakage of Class V flowable and packable composite resin restorations.

Class V composite restorations are subject to the stresses that induce non-carious cervical lesions. This study evaluated the effect of eccentric oblique load on microleakage of restorations. Class V cavities were randomly prepared on the buccal surfaces of 40 recently extracted premolars and restored with composite resin according to manufacturers' directions. Teeth were randomly assigned to one of four treatment groups with 10 teeth per group: (1) flowable resin (Revolution) without load cycling; (2) packable resin (Prodigy Condensable) without load cycling; (3) flowable resin with load cycling (200,000 cycles) and (4) packable resin with load cycling (200,000 cycles). All teeth were then immersed in 2% methylene blue solution for 24 hours after thermocycling (500 cycles). Dye penetration was measured (scores 0-3). The results indicated that adding load cycling significantly increased microleakage (p < 0.05). No significant differences in microleakage were observed for flowable resin vs packable resin. Gingival margins had significantly more microleakage (p < 0.05) than occlusal margins.     

The marginal seal of Class II restorations: flowable composite resin compared to injectable glass ionomer

The objective of this study was to investigate the effect of a flowable composite resin (Tetric Flow) versus an injectable glass ionomer (Fuji II LC) on microleakage at the cavosurface margin of the proximal box of Class II restorations in permanent teeth in-vitro. Thirty caries and restoration-free human bicuspids were prepared with mesial and distal slot preparations and were filled either with a bonding agent (Optibond) plus a flowable composite resin (Tetric Flow), Group I; bonding agent (Optibond) plus a flowable glass ionomer (Fuji II LC), Group II; or a flowable glass ionomer (Fuji II LC) with no bonding agent, Group III. All specimens were then immersed in a 2% solution of basic fuschin dye for 24 hours to allow for dye penetration into possible existing gaps. These teeth were then carefully sectioned mesially/distally into two pieces using an Isomet saw. The teeth were then studied under a binocular microscope to measure depths of dye penetrations as an indication of marginal microleakage at the gingival cavosurface margin and scored as follows: 0 = no dye penetration, 1 = dye penetration into enamel only, 2 = dye penetration into enamel and dentin, 3 = dye penetration into the pulp. The specimens were also evaluated using a SEM. The results showed that there were statistically significant differences between Groups I (Tetric Flow) and (Fuji II LC plus bonding agent), II in favor of Group I; between Groups I and (Fuji II LC with no bonding agent), III in favor of Group I; as well as Groups II and III in favor of Group II (Fuji II LC plus bonding agent). Group I (bonding agent plus flowable composite resin) showed significantly less microleakage. Group II (bonding agent plus flowable glass ionomer) demonstrated a bond that existed between the bonding agent and the glass ionomer but microleakage within microgaps of the glass ionomer itself Group III (flowable glass ionomer plus no bonding agent) demonstrated significant microleakage between the glass ionomer and tooth structure, microgaps within the glass ionomer, and lack of retention of the restoration. It appears that the use of a flowable composite resin (Tetric Flow) plus a bonding agent (Optibond) in the proximal box of a Class II restoration in permanent teeth will significantly reduce the microleakage at the cavosurface margin when compared with an injectable glass ionomer (Fuji II LC) with or without a bonding agent (Optibond).     

乳牙空气喷磨对三种材料充填微渗漏的影响

目的体外评价乳牙空气喷磨备洞后,三种材料充填微渗漏情况的比较。方法30颗离体乳磨牙分为3组,均空气喷磨备洞。组Ⅰ(n=10):纳米复合树脂充填。组Ⅱ(n=10):流动纳米树脂充填。组Ⅲ(n=10):光固化纳米玻璃离子充填。热循环处理后亚甲基蓝溶液染色观察。结果三组间充填体微渗漏率差异有显著性(P<0.001),以流动树脂微渗漏率最低(P<0.05)。结论可流动纳米树脂用于乳牙空气喷磨备洞后充填可获得较好的边缘封闭性。     

Microleakage of posterior packable resin composites with and without flowable liners

The use of flowable composites as liners in Class II packable composites has been suggested by some manufacturers. However, the contributions of this technique are unproven. This study evaluated marginal microleakage in Class II packable composite restorations with and without the use of a flowable composite liner. A conventional microhybrid composite was used as a control. Microleakage at occlusal and gingival margins of Class II cavities was evaluated using 45Ca and autoradiographs. Fifty non-carious, restoration-free human molar teeth were used. Separate mesio-occlusal and disto-occlusal Class II cavity preparations were made in each tooth. Gingival margins of all cavities were placed 1 mm apical to the cementoenamel junction (CEJ). Four Packable composites (Alert, Surefil, Pyramid and Solitaire) and one conventional microhybrid composite (Renew) with their respective manufacturer's bonding agents were used to restore the cavities. One side of each tooth was restored with composite alone, while the other side was restored with the composite lined with that manufacturer's flowable liner. The restored teeth were thermally stressed and 45Ca was used to evaluate microleakage. Two independent evaluators scored leakage based on the autoradiographs. The results showed flowable composites helped reduce microleakage at gingival margins of Class II restorations (p < 0.05). Gingival margins had higher microleakage than occlusal margins (p < 0.05). Without flowable liners, three packable composites (Alert, Pyramid and Surefil) showed higher leakage (p < 0.05) than the microhybrid control. Only Solitaire packable composite without liner showed no significant difference in microleakage to the control (p > 0.05). Although the flowable liners help reduce microleakage, Alert and Pyramid packable composites with liners still showed higher leakage than the control (p < 0.05). Surefil and Solitaire packable composites with flowable liners showed no significant difference in microleakage (p > 0.05) to the control.     

排龈联合流动树脂衬层技术修复楔状缺损临床疗效观察

目的：评估采用排龈联合流动树脂衬层技术修复楔状缺损的临床疗效。方法选择65例楔状缺损患者,每个患者的双侧上颌前磨牙均存在齐龈的4个楔状缺损（共260颗牙）,将每个患者的4颗楔状缺损牙随机分为Ⅰ、Ⅱ、Ⅲ、Ⅳ4组,分别用光固化复合树脂直接充填,排龈+光固化复合树脂直接充填,光固化流动树脂衬层+复合树脂充填,排龈+光固化流动树脂衬层+复合树脂充填4种方式进行修复,于修复后1年进行观察对比。以改良的美国公共卫生署的直接临床评价系统（USPHS）评估疗效,数据进行卡方检验。结果1年复查结果显示,色泽协调性、边缘着色、边缘密合性、表面形态4个方面,4组间A、B分级间差异均无统计学意义（P>0.05）。成功率方面Ⅰ组和Ⅳ组间差异有统计学意义（P<0.05）,Ⅳ组排龈+光固化流动树脂衬层+复合树脂充填临床疗效最好。结论排龈联合光固化流动树脂衬层技术,然后再行复合树脂充填是比较好的楔状缺损修复方式。     

The effect of flowable resin composite on microleakage and internal voids in class II composite restorations

This in vitro study evaluated the influence of two flowable resin composites on marginal microleakage and internal voids in Class II composite restorations with the margins below the cementoenamel junction (CEJ). Class II cavities randomly divided into four groups: Group I-Filtek with Filtek Flow lining; Group II-Filtek; Group III-Tetric Ceram with Tetric Flow lining; Group IV-Tetric Ceram. After thermocycling tests (5-60 x 1500) and dye soaking, the teeth were sectioned in a mesiodistal direction along their longitudinal axis. Gingival-marginal microleakage and internal voids in three separate portions of the restoration (interface, cervical and occlusal voids) were observed with a microscope. Statistical analyses indicated that the use of flowable resin composites (Groups I and III) provided a reduction in marginal microleakage and a reduction in some parts of the internal voids or total voids (p<0.05). The condensable material (Filtek) in combination with the flowable liner showed fewer voids (interface, occlusal, total) than the hybrid resin (Tetric) (p<0.05). There was a correlation between the number of internal voids or total voids and the marginal microleakage (p<0.05). It was concluded that a composite lining in a Class II resin composite with margins below the cementoenamel junction may reduce marginal microleakage and voids in the interface and the total number of voids in the restoration.     

Microleakage of four core materials under complete cast crowns

This study evaluated the microleakage patterns of complete cast-metal crowns cemented onto teeth that were rebuilt with pin-retained cores made from cast metal, composite resin, acrylic resin and amalgam by using four different cements. One hundred extracted human teeth were used to compare the microleakage of composite resin core, metal core, acrylic resin core and amalgam core, and regular crown preparations under a complete cast metal crown cemented with different cements as determined by 2% methylene blue dye solution. Specimens were compared with and without aging after cementation in a thermal bath by cycling some of them between 4 degrees C and 50 degrees C in a 2% methylene blue bath and others in a similar bath held at 37 degrees C. The extent of marginal microleakage was evaluated with a stereomicroscope and scored. It was determined through variance analysis that the type of core used in the substructure, the cement used for cementing and the thermocycling process were all important in microleakage. No significant differences in the degree of microleakage were found under crowns cemented onto teeth rebuilt with the four core materials when cemented with the same luting cement.     

Influence of adhesive system and placement technique on microleakage of resin-based composite restorations

PURPOSE: To analyze the influence of two placement techniques and two adhesive systems on the marginal microleakage of Class II resin-based composite restorations using different resin composite materials. MATERIALS AND METHODS: Two hundred standardized Class II cavities (5 mm x 3 mm x 1.5 mm) were cut in human premolars and restored using five resin composite materials (A.L.E.R.T.-AL, Solitaire-SO, SureFil-SU, Filtek A110-A, and Z100-Z), two adhesive systems (Bond 1-B1 and Etch & Prime 3.0-EP), and two placement techniques (incremental or bulk). Specimens were thermocycled (700 cycles, 5 degrees - 55 degrees C, 1 min dwell time), immersed in 0.5% methylene blue solution for 4 h, and sectioned longitudinally to evaluate the extent of microleakage. Data were submitted to statistical analysis using the Kruskal-Wallis test. RESULTS: It was observed that both adhesive systems presented similar results (p > 0.05), and neither achieved complete marginal sealing. The bulk placement technique led to greater microleakage than the incremental technique (p < 0.001). Restorations prepared using SO resin composite showed greater microleakage than those performed using Z or AL materials. However, SO obtained similar values of microleakage when compared to SU and A materials. CONCLUSION: The use of incremental placement technique resulted in less microleakage for Class II resin-based composite restorations. No difference was observed among adhesive systems regarding prevention of marginal dye penetration. Furthermore, the type of resin composite material employed for restoration may have an influence on the extent of microleakage.     

不同窝洞处理剂对银汞合金充填微渗漏的影响

目的：探讨减少银汞合金充填后边缘微渗漏的有效方法。方法：选择无龋的离体磨牙４８个，随机分为４组，每个牙分别制面洞、颊面颈１／３洞。比较几种窝洞洞壁处理后对微渗漏的影响。结果：银汞合金充填１个月后，１０％ＥＤＴＡ处理窝洞组、１０％ＥＤＴＡ加护洞漆组与空白组之间的边缘微渗漏无明显差异，而含３％ＦｅＣｌ３的１０％枸橼酸（１０－３液）处理加银汞合金粘结剂组则明显减少微渗漏。结论：离体牙实验证明银汞合金粘结修复可明显减少银汞合金充填术后的微渗漏     

Composite restorations: influence of flowable and self-curing resin composite linings on microleakage in vitro

This in vitro study evaluated the microleakage at enamel (occlusal) and dentin (gingival) margins of MOD resin composite restorations made with different incremental insertion techniques. MOD cavities were prepared on 60 extracted human molars with the proximal margins placed 1 mm below the cemento-enamel junction. All teeth were acid-etched and treated with One-Step adhesive, then restored with a hybrid resin composite (Renew) with and without a flowable composite (AEliteflo) or a self-curing composite (Bisfil 2B) as the first increment in the proximal boxes. The time of placement of the second increment in relation to curing of the first increment was also varied. After polishing, the teeth were soaked in 0.5% basic fuchsin for 24 hours, sectioned and evaluated for dye penetration. None of the restorative techniques prevented microleakage at the enamel and dentin margins. However, microleakage at dentin margins were significantly reduced by the use of a flowable composite as the first increment in the proximal boxes. Time of placement in relation to curing had no influence on microleakage. Microleakage was lower at enamel margins than at dentin margins; however, besides microleakage at the enamel-restoration interface, 37 of the 60 restored teeth (62%) displayed at least one white line in enamel adjacent to the composite restoration.     

Microleakage of endodontically treated teeth restored with prefabricated posts and tooth-colored restorative materials

This study evaluated the microleakage of endodontically treated teeth restored with prefabricated dowels and tooth-colored restoratives (Solitaire, Surefil, Filtek P60, Admira, Z-100) as core materials with and without the use of a flowable composite liner. A total of 200 extracted premolars were endodontically treated and prepared for post-core restorations. Prefabricated posts were inserted and cemented with resin cement into the root canals. Each resin system included the corresponding bonding agent for each respective flowable composite. For each group, half of the teeth were restored with composite alone, while the others were restored with the composite lined with flowable liner. Teeth were thermocycled for 1,000 cycles between 5 and 55 degrees C using a 30-second dwell time. The teeth were then coated with nail polish, placed in 5% methylene blue for 24 hours, sectioned, and scored for microleakage. Flowable liners reduced microleakage. Z-100 both with and without flowable liner demonstrated better resistance to leakage. Solitaire, Admira, and Filtek P60 showed more leakage than the other materials.     

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.     

Factors affecting microleakage of a packable resin composite: an in vitro study

This study was designed to determine the effects of three factors on the microleakage of a packable resin composite: different adhesive systems (single-step self-etching adhesive or total-etch and one-bottle adhesive), the use of a flowable resin composite (as a liner) and the different techniques of cavity preparation. Sixty extracted non-carious human first and second molars were selected and randomly divided into six groups. Cervical cavities were prepared using the conventional technique on the distal sides and the air-abrasive technique was used on the mesial sides of the teeth. The experimental groups were restored with PQ1 + SureFil or Prompt L-Pop + SureFil with or without PermaFlo. In the control groups, only SureFil was used on 10 teeth and PermaFlo + SureFil was applied on the remaining 10 teeth. The restored teeth were stored in 100% humidity at 37 degrees C for 24 hours and thermocycled between 5 degrees C and 55 degrees C for 100 cycles. Each tooth was immersed in India ink for 48 hours, then sectioned. Dye penetration at the occlusal and gingival margins was scored by two independent operators. The data were statistically analyzed to assess the differences between the test and control groups. No significant differences among the adhesives in terms of the occlusal margins of the cavities were observed. However, PQ1 led to less microleakage compared to Prompt L-Pop at the gingival margins (p < 0.0062). When flowable resin composite was used with Prompt L-Pop, microleakage was reduced (p < 0.0125). However, no significant difference was observed between the two cavity preparation techniques (p > 0.0125).     

Microleakage of core materials for complete cast gold crowns

This study evaluated the microleakage patterns of complete cast-gold crowns cemented onto teeth rebuilt with pin-retained cores made from cast gold, amalgam, composite resin, and silver-reinforced glass ionomer by using three different cements (zinc phosphate, glass ionomer, and resin cement). Crowns cemented onto unrebuilt tooth preparations with zinc phosphate cement served as controls. The cemented specimens were thermocycled between 4 degrees and 50 degrees C in waterbaths. They were then embedded in epoxy resin and sectioned. The extent of marginal microleakage was evaluated with a stereomicroscope and scored. The findings indicated that the type of luting agent used appeared to affect microleakage more than the core material. No significant differences in the degree of microleakage were found under crowns cemented onto teeth rebuilt with the four core materials when cemented with the same luting cement.     

Microleakage study of flowable composite resin systems

The purpose of this in vitro microleakage study was to evaluate four low-viscosity composite resin systems. Each resin system included the corresponding bonding agent for each respective flowable composite. A hybrid material was used as a control. A total of 75 noncarious, freshly extracted human teeth were prepared with a Class 5 occlusal preparation and a gingival preparation at the cementoenamel junction. The materials were inserted according to the manufacturers' recommendations using the single-component bonding agent for each system. Teeth were thermocycled 800 times between 5 degrees C and 55 degrees C with 30-second dwell times. The teeth were then coated with nail polish 1 mm short of the restoration, placed in a basic fuchsin dye for 24 hours, and sectioned with a diamond wheel. Enamel and dentin/cementum margins were analyzed for microleakage on a scale of 0 (no leakage) to 3 (axial wall). Results were evaluated with the Fisher's exact test. The results of the study indicate that there was no leakage at the enamel margin of any restorations. No statistically significant differences in microleakage were found in dentin/cementum margins among the samples in the experimental group or between the experimental group and control group. The results indicate flowable composites demonstrate resistance to microleakage in both enamel and cementum/dentin margins similar to TPH hybrid composite.     

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.     

流动性充填材料用于预防性树脂充填的实验研究

目的　以传统的复合树脂+窝沟封闭剂的方法为对照组,用体外实验的方法评价流动树脂、流动复合体在预防性树脂充填(preventiveresinrestoration ,PRR)治疗中的情况。方法　患小面积龋被拔除第三恒磨牙9颗,分别用流动树脂(A组)、流动复合体(B组)和传统的复合树脂材料+窝沟封闭剂(C组)的方法进行PRR治疗。5 0 %AgNO3 浸染法检查微渗漏;用SEM观察树脂与牙齿的结合情况。结果　①渗透实验表明各实验组和对照组中均存在一定程度的微渗漏;在微渗漏率方面,A组低于对照的C组(P <0 .0 5 ) ,在树脂渗透率方面A组低于B组和C组(P <0 .0 5 )。②SEM上显示A与B组相似,多数标本树脂与牙齿接触的界面上有结合良好的树脂突样结构,但树脂在和窝沟底部与牙体组织结合较差,特别在极细窝沟处;C组中结合良好的界面所占比例较少,复合树脂勉强压入窝洞后充填不实,在沟底部常见宽大裂纹。结论　在流动复合体和流动树脂在PRR治疗时更适用于沿窝沟走向侵润的窄长形态的窝沟内龋,而传统PRR法更适用于单个龋损直径在1 .5～2mm左右的圆形或卵圆形的小面积龋,流动性充填材料在PRR治疗中可作为传统法的一种补充,最大限度地保留健康牙体组织。     

Microleakage with Gluma: effects of unfilled resin polymerization and storage time

An earlier study showed that the Gluma Bonding System permitted more microleakage than other dentin bonding agents. In that study, the unfilled resin was not polymerized prior to placement of the composite resin, as per manufacturer's instructions. The unfilled resin was cured in the other test groups. To evaluate the effect of unfilled resin polymerization on microleakage, Class V cavity preparations were made in sound extracted teeth. Composite resin restorations were placed using the Gluma Bonding System and a microfilled composite resin. In some samples, the unfilled resin was cured prior to placement of the composite. In others, the unfilled resin and composite were polymerized simultaneously. The samples were stored for either 24 hours or 30 days, then thermocycled. Microleakage was evaluated with a silver nitrate staining method. Specimens in which the unfilled resin had not been cured separately and which had been stored for 24 hours had the most leakage. Significantly less microleakage occurred when the unfilled resin was polymerized separately and/or when storage time was 30 days. To reduce microleakage with the Gluma Bonding System, the authors recommend polymerization of the unfilled resin before placement of the composite.