Influence of finishing technique on microleakage

Four different finishing techniques were used in a dentin bonding agent/composite resin restoration to evaluate the possible influence of finishing technique on microleakage. Results indicated that finishing technique affects the ability of the restorative system to resist microleakage. Under the conditions of this study, best results were achieved with a 30-fluted bur followed by a short wet polish. Samples finished dry with polishing disks demonstrated considerable microleakage. This study also suggests that homogeneous nonagglomerated microfilled composite resin does not require disk finishing.     

Effect of aluminum chloride hemostatic agent on microleakage of class V composite resin restorations bonded with all-in-one adhesive

Objectives: Since hemostatic agents can induce changes on enamel and dentin surfaces and influence composite resin adhesion, the aim of the present study was to evaluate the effect of the aluminum chloride hemostatic agent on the gingival margin microleakage of class V (Cl V) composite resin restorations bonded with all-in-one adhesive. Study design: Cl V cavities were prepared on the buccal surfaces of 60 sound bovine permanent incisors. Gingival margins of the cavities were placed 1.5 mm apical to the cemento-enamel junction (CEJ). The teeth were randomly divided into two groups of 30. In group 1, the cavities were restored without the application of a hemostatic agent; in group 2, the cavities were restored after the application of the hemostatic agent. In both groups all-in-one adhesive and Z250 composite resin were used to restore the cavities with the incremental technique. After finishing and polishing, the samples underwent a thermocycling procedure, followed by immersion in 2% basic fuschin solution for 24 hours. The samples were sectioned and gingival microleakage was evaluated under a stereomicroscope. The non-parametric Mann-Whitney U test was used to compare microleakage between the two groups. Statistical significance was defined at P<0.05. Results: A statistically significant difference was observed in microleakage between the two groups (P<0.001). Conclusions: Contamination of Cl V composite resin restorations bonded with all-in-one adhesive with aluminum chloride hemostatic agent significantly increases restoration gingival margin microleakage. Key words:All-in-one adhesive resin, composite resin restoration, hemostatic agent, microleakage.     

Effect of aluminum chloride hemostatic agent on microleakage of class V composite resin restorations bonded with all-in-one adhesive

Objectives: Since hemostatic agents can induce changes on enamel and dentin surfaces and influence composite resin adhesion, the aim of the present study was to evaluate the effect of the aluminum chloride hemostatic agent on the gingival margin microleakage of class V (Cl V) composite resin restorations bonded with all-in-one adhesive. Study design: Cl V cavities were prepared on the buccal surfaces of 60 sound bovine permanent incisors. Gingival margins of the cavities were placed 1.5 mm apical to the cemento-enamel junction (CEJ). The teeth were randomly divided into two groups of 30. In group 1, the cavities were restored without the application of a hemostatic agent; in group 2, the cavities were restored after the application of the hemostatic agent. In both groups all-in-one adhesive and Z250 composite resin were used to restore the cavities with the incremental technique. After finishing and polishing, the samples underwent a thermocycling procedure, followed by immersion in 2% basic fuschin solution for 24 hours. The samples were sectioned and gingival microleakage was evaluated under a stereomicroscope. The non-parametric Mann-Whitney U test was used to compare microleakage between the two groups. Statistical significance was defined at P<0.05. Results: A statistically significant difference was observed in microleakage between the two groups (P<0.001). Conclusions: Contamination of Cl V composite resin restorations bonded with all-in-one adhesive with aluminum chloride hemostatic agent significantly increases restoration gingival margin microleakage.     

Assessing microleakage in resin composite restorations rebonded with a surface sealant and three low-viscosity resin systems.

OBJECTIVES: The aim of this study was to assess the ability of three low-viscosity resin systems (Unibond, Single Bond, and Fluorseal), used as rebonding agents, and a specific surface-penetrating sealant (Fortify) to prevent microleakage in Class V resin composite restorations. METHOD AND MATERIALS: Fifty Class V cavities with the occlusal margin in enamel and the cervical margin in dentin and cementum were prepared on both the buccal and lingual surfaces of sound extracted premolars and restored with a hybrid light-cured resin composite. After finishing and polishing, restorations were randomly assigned to one of five equal groups (n = 10): a control, without surface sealing, and four experimental groups in which margins were etched and rebonded. Specimens were thermocycled, immersed in a 50% silver nitrate solution, sectioned longitudinally, and analyzed for leakage at the occlusal and cervical interfaces. RESULTS: Statistical analysis showed significantly less leakage at the enamel margins for all groups. Fortify and Unibond were statistically similar and provided better marginal sealing at dentin and cementum interfaces. Fluorseal showed the poorest ability to prevent microleakage. CONCLUSION: The rebonding technique may substantially minimize microleakage at dentin and cementum margins of composite restorations, when a resin system with sufficiently low viscosity is used as a surface sealant, regardless of whether it has been specified for such a purpose.     

不同桩核和粘接系统冠向微渗漏的实验研究

目的:通过染色法测量冠向微渗漏的大小,比较不同桩核及粘接剂的冠向封闭能力.方法:选择50 颗离体下颌单根管前磨牙,使用ProTaper镍钛锉冠向下法进行根管预备.样本随机分为6 组.A组为暂封组、B组为树脂粘接纤维桩核组, C组为树脂粘接铸造金属桩核组, D组为磷酸锌粘固铸造金属桩核组, E组为阳性对照组,F组为阴性对照组.除阳性对照组,所有根管侧向加压法充填.桩道预备和桩核修复后印度墨水染色1 周,透明处理,体视显微镜下观察冠向染料渗入情况.结果:暂封组冠向微渗漏值明显大于各桩核修复组(P<0.05);树脂粘接的纤维桩组与金属桩组之间无统计学差异(P>0.05);树脂粘接的纤维桩组和金属桩组的冠向微渗漏值均明显小于磷酸锌粘固组(P<0.05).结论:桩核修复可以减小冠向微渗漏,树脂粘接材料封闭效果更好.     

Margin quality and microleakage of Class II composite resin restorations

Margin quality and isotope microleakage analyses of Class II restorations placed in extracted human molars were compared using various composite resins and placement techniques. At occlusal margins, the traditional (experimental) composite resin restoration placed by the incremental technique showed less microleakage than did the traditional (commercial) [corrected] composite resin restoration placed by the bulk technique. In each group, the occlusal and proximal adaptations had significantly higher "excellent margin" than did the cervical adaptation. Thus, the marginal adaptation at the cervical aspect of conventional Class II composite resin restorations may present a problem with respect to microleakage.     

Effect of polishing techniques and time on surface roughness, hardness and microleakage of resin composite restorations

This study evaluated the effects of immediate and delayed polishing on the surface roughness, microhardness and microleakage of a microfilled (Filtek A110) and a hybrid (Filtek Z250) resin composite. Standardized preparations were made on the buccal surfaces of 256 bovine teeth; half were restored with each composite (128 teeth per composite). Immediately after curing, gross finishing was carried out with #280 sandpaper. The specimens restored with each composite were divided into two subgroups. The first group (IM) was polished immediately after gross finishing, using three different systems (n=16): Sequence A, Sof-Lex; Sequence B, Flexicups and Sequence C, Flexicups + Jiffy Polishing Brush + Flexibuffs. The specimens were then stored for three weeks in saline 37 degrees C. The second group (DE) was stored for two weeks, then polished with the same systems and stored for one additional week. The controls (n=16) were analyzed without polishing. Five readings per specimen were taken for surface roughness and hardness. After immersion in basic fuchsin, microleakage was evaluated (40x) using standardized scores. The data were analyzed at a significance level of 0.05, with analysis of variance and an SNK test (surface roughness and microhardness) or with Kruskal-Wallis (microleakage). In both composites, only for the sequential technique was there an influence of delay in polishing on roughness (Ra). Flexicups exhibited the highest Ra of the three systems. The IM and Filtek Z-250 groups showed higher hardness than the DE and Filtek A-110 groups, respectively. Dentin margins showed more leakage than enamel margins; the sequential technique produced more leakage than the other techniques in dentin (p<0.05) and delay of polishing was not significant in the majority of situations. In conclusion, several conditions--composite, time and polishing technique--had a significant influence on surface roughness, hardness and microleakage. Generally, immediate polishing produced no detrimental effect compared to delayed polishing.     

The influence of finishing time on the marginal seal of a resin-modified glass-ionomer and polyacid-modified resin composite

The aim of this study was to compare the effect of immediate and delayed finishing on the microleakage of encapsulated resin-modified glass-ionomer, Fuji II LC and a polyacid-modified resin composite, Dyract compomer at both the enamel and dentine margins. Standardized Class V cavities were prepared along the cemento-enamel junction on buccal and palatal surfaces of 24 freshly extracted non-carious premolars. Equal numbers of buccal and palatal cavities in each group were restored with Fuji II LC and Dyract compomer following the manufacturer's instructions. The groups with delayed finishing were restored 1 week earlier, stored in saline at 37 degrees C and finished on the same day as the groups with immediate finishing. The specimens were then thermocycled 500 times and subjected to dye penetration testing. The results showed that both materials leaked more at the dentine than enamel margins for both regimes of finishing methods. There was no statistical difference in the microleakage of Dyract finished immediately or later at enamel and dentine margins and Fuji II LC finished immediately or later in dentine. However, a statistical difference existed between the microleakage in Fuji II LC finished immediately and later in enamel.     

Effect of finishing time and techniques on marginal sealing ability of two composite restorative materials

STATEMENT OF PROBLEMS: Finishing of composites may adversely influence the sealing ability of direct adhesive restorations. PURPOSE: This study was conducted to determine whether finishing time and techniques under wet or dry conditions affect the microleakage of 2 types of class V composite restorations. MATERIAL AND METHODS: Eighty class V preparations were made in the buccal surfaces of noncarious molars with the occlusal margins ending in enamel and the gingival margins in dentin. Dental adhesive (Single Bond) was applied according to the manufacturer's instructions. Half of the preparations were restored with a microfilled composite (Silux Plus) and the other half with a hybrid composite (Filtek Z250). Within each major composite group (n = 40), 4 subgroups (n = 10) were established based on finishing technique (diamond finishing burs or aluminum oxide discs) and finishing time (immediate or delayed by 24 hours). The specimens were stored for 24 hours in 37 degrees C water, thermocycled for 250 cycles between 5 degrees C and 55 degrees C, immersed in 2% methylene blue solution for another 24 hours, and sectioned longitudinally. For both enamel and dentin margins, dye solution penetration at the tooth/composite interface was scored from 0 to 4 under stereoscopy at original magnification x 20. Data were analyzed with the Kruskal-Wallis test (P<.05). RESULTS: Significantly lower leakage scores were recorded for teeth restored with microfilled composite and finished under wet conditions after 24 hours (P<.01). No significant differences were found among the hybrid composite groups. CONCLUSION: For microfilled composite restorations on dentin margins, delayed wet finishing with diamond burs resulted in significantly lower microleakage scores than all other finishing protocols. Hybrid composite restorations had equivalent levels of microleakage regardless of the finishing method.     

不同桩核微渗漏情况的体外研究

目的 :比较成品桩钉加复合树脂核、传统银汞桩核和粘结银汞桩核冠向微渗漏情况 ,探讨粘结银汞桩核在后牙修复中的应用前景。方法 :30颗新拔除的磨牙分为 3组 ,分别用成品桩钉加复合树脂核、传统银汞桩核和粘结银汞桩核修复后放入印度墨水中 1周 ,另选择 10颗磨牙作为阴性和阳性对照 ,评价冠方微渗漏情况。结果 :粘结银汞桩核微渗漏明显小于传统银汞桩核 (P <0 .0 1) ;传统银汞桩核与成品桩钉加复合树脂核差异无显著性 (P >0 .0 5 )。结论 :粘结银汞桩核修复可有效降低微渗漏 ,预防桩核修复后因微渗漏导致的并发症     

Effect of cooled composite inserts in the sealing ability of resin composite restorations placed at intraoral temperatures: an in vitro study

Polymerization shrinkage causes microleakage of resin composite restorations. New materials and operative techniques should be developed in order to reduce polymerization shrinkage. This research studied the effects of cooled composite inserts and room-temperature composite inserts in the sealing ability of resin composite restorations placed at intraoral temperatures. Forty-eight extracted human molars (providing a total of 155 sections) were kept at intraoral temperatures, and Class V cavities were restored with an ormocer-based resin composite (Admira, Voco). Three restorative techniques were used: conventional bulk insertion (Group I or control group) (n = 53 sections), room-temperature resin composite inserts (Group II) (n = 52) and cooled resin composite inserts (Group III) (n = 50). Microleakage and penetrating microleakage were studied under the microscope. Cooled composite inserts reduce microleakage at the gingival margins with respect to Groups I (p = 0.002) and II (p = 0.014). When small-size cooled composite inserts were used, the sealing ability at the gingival margins of Class V composite restorations was improved with respect to the bulk insertion technique and the room-temperature composite inserts technique.     

Microleakage of resin composite restorations with glass-ceramic inserts.

OBJECTIVE: The purpose of this study was to evaluate the effects of glass-ceramic inserts and different application techniques of resin composites on marginal leakage. METHOD AND MATERIALS: Three groups of 10 standardized, round, Class V cavities were prepared on the buccal surface of 30 extracted human molar teeth. Group 1 received resin composite restorations, placed in one increment (bulk). Group 2 received resin composite restorations that were placed in two increments, and group 3 received resin composite restorations with beta-quartz ceramic inserts. After the teeth were thermocycled and placed in 0.5% basic fuchsin for 24 hours, they were sectioned and examined for microleakage. RESULTS: On the occlusal margins, there was no statistically significant difference between the restorations placed with the incremental technique and the restorations with beta-quartz inserts. The restorations placed with the bulk technique had significantly more microleakage than did the others. On the gingival margins, the restorations with beta-quartz inserts exhibited significantly less microleakage than did the other groups. The restorations placed with the bulk technique showed significantly more dye penetration than did the others. CONCLUSION: The use of a glass-ceramic insert reduced the marginal leakage of Class V resin composite restorations.     

Microleakage of etched-dentin composite resin restorations.

Some clinicians now advocate dentinal etching to eliminate microleakage around composite resin margins. This study evaluated the "Kanca technique" and three commercial dentinal adhesives, including Clearfil Photo Bond, which uses phosphoric acid to etch dentin. The Kanca technique and Tenure were the most effective systems tested. However, none of the bonding systems completely eliminated microleakage. Total sealing of dentinal margins is not predictable with current adhesives and composite resins.     

In vitro microleakage study of a condensable and flowable composite resin

The aim of this study was to evaluate the in vitro microleakage of a condensable composite resin recommended for Class II restorations with and without a flowable composite resin as a liner. There were statistically significant differences between all groups and between individual groups (p < 0.05). The results showed significantly less microleakage in teeth restored with flowable composite resin underneath a condensable composite resin.     

Er,Cr:YSGG激光制洞对光固化复合树脂边缘微渗漏的影响

目的:比较在自酸蚀黏结剂的应用条件下,Er,Cr:YSGG激光制备与传统牙钻制备离体牙牙颈部洞对光固化复合树脂边缘微渗漏的影响。方法:将20个因正畸拔除的新鲜完整无龋损、无隐裂、无充填物的前磨牙随机分为两组(n=10),分别使用牙钻和Er,Cr:YSGG激光制备牙颈部洞。窝洞制备后均匀涂覆FL-BOND,用TPH复合树脂进行分层充填,打磨、抛光,37℃生理盐水中存放7 d后,进行500次温度循环实验(5±2)℃—(55±2)℃。将上述所有样本置0.5%碱性品红液中室温浸泡24 h后,沿牙体长轴通过修复体正中纵行剖开,采用染料渗入法和扫描电镜方法观察充填体微渗漏情况,运用SPSS 11.0软件包进行统计学处理。结果:牙钻制备组与激光组相比,无论牙合壁还是龈壁的染料渗入评分和边缘微缝隙宽度均无显著性差异(P>0.05)。结论:在自酸蚀黏结剂的应用条件下,Er,Cr:YSGG激光制洞不能显著减少光固化复合树脂边缘微渗漏的发生。     

Marginal microleakage of resin-retained bridges in association with existing resin composite and amalgam restorations

The aim of this study was to determine the microleakage associated with resin-retained bridge retainers cemented over amalgam and resin composite restorations. Cavities prepared on the labial surfaces of bovine incisors were restored with either amalgam or a posterior resin composite. Non-precious nickel-chromium alloy frameworks were then attached to the teeth by use of one of four cements: Conclude, ABC, Panavia Ex, and Superbond. The specimens were then stored for two weeks or six months, thermocycled, and tested for microleakage by use of a radioactive tracer and an autoradiographic technique. The results showed that more leakage was associated with the amalgam restorations than with the teeth filled with resin composite. Leakage scores increased with time with both the amalgam and composite restorations, except for the Panavia Ex and ABC materials, respectively.     

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.     

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.     

Microleakage evaluation of a new low-shrinkage composite restorative material

PURPOSE: This study compared the microleakage of an experimental low-shrinkage resin composite (Hermes), a nanofilled resin composite material (Filtek Supreme) and a hybrid resin composite (Tetric Ceram) using a dye penetration method. METHODS AND MATERIALS: Class I cavities prepared in 60 human molars were randomly divided into 3 groups according to the restorative material used. The preparations were restored using a bulk or an incremental technique. Half of the specimens from each group were subjected to 200,000 cycles of loading at 50 N, while the other half were stored in distilled water for 24 hours at 37 degrees C. All specimens were immersed in 1% methylene blue (pH = 7.0) for 24 hours and sectioned into 3 slabs. The margins were evaluated for microleakage using an ordinal scoring system (0-4) under a stereomicroscope at 40x magnification. Data were subjected to the non-parametric Kruskal-Wallis analysis of variance and Mann-Whitney test (p<0.05). Data were expressed as median leakage scores and mean ranks. RESULTS: All of the restorative systems had microleakage, regardless of the insertion technique and mechanical load cycling. Incremental placement significantly reduced microleakage as compared to the bulk technique, regardless of the restorative system used. Load cycling significantly affected incrementally placed restorations, except for the Hermes system.     

Effect of different application and polymerization techniques on the microleakage of proximal resin composite restorations in vitro

This in vitro study investigated cervical microleakage of proximal resin composite restorations placed with three application and polymerization techniques. Uniform mesio-occlusal-distal (MOD) preparations featuring cervical margins above (mesial) and below (distal) the CEJ suitable for restoration with resin composite were copy milled into 33 recently extracted permanent molars. The teeth were divided randomly into three groups of 11 teeth and restored using a conventional incremental technique (Group A) and two novel curing devices (Groups B and C). After 24 hours, a dye penetration test was used to assess microleakage. Conventional placement in preparations with cervical margins in enamel had significantly lower interfacial leakage scores than those recorded for placement in preparations with margins in cementum regardless of the technique used to place the restorative material. Use of the two novel curing devices conferred no advantage in reducing microleakage irrespective of where preparation margins were placed.