Microleakage of Compoglass-F and Dyract-AP compomers in Class V preparations after salivary contamination

PURPOSE: The purpose of this study was to investigate the effect of salivary contamination on the microleakage within Class V preparations of teeth restored with either Compoglass-F/Syntac SC and Dyract-AP/Prime and Bond 2.1. METHODS: Class V cavity preparations with occlusal margins in enamel and gingival margins in cementum were prepared on the buccal and lingual surfaces of extracted human permanent molar teeth. Preparations were distributed randomly into 4 treatment groups (N = 16) consisting of the two compomers and their respective bonding agents with and without salivary contamination. After treatment, the samples were stored in tap water for 24 hours, thermocycled, stained with dye, sectioned, and scored for microleakage. RESULTS: Salivary contamination had no significant effect on enamel microleakage but significantly increased both linear and penetrating microleakage versus non-contaminated for both compomer/dentin bonding systems. CONCLUSION: These data indicate salivary contamination adversely effects gingival but not enamel microleakage when Class V restorations are restored with either Compoglass F/Syntac SC or Dyract-AP/Prime and Bond 2.1.     

An in vitro comparison of marginal microleakage of alternative restorative treatment and conventional glass ionomer restorations in extracted permanent molars

PURPOSE: The objective of this study was to compare the marginal leakage of cervical restorations made using alternative restorative treatment (ART) and conventional glass ionomer restorations. METHODS: Sixteen permanent maxillary and mandibular first and second molars extracted for periodontal reasons with Class V carious dentin on the buccal surfaces were prepared using ART while a second set of 29 noncarious molars had Class V preparations made with a high-speed handpiece. The occlusal margin was located in the enamel, and the gingival margin was located in the dentin/cementum. All teeth were restored with glass ionomer cement (GIC). The teeth were thermally stressed for 300 cycles and stained with methylene blue. Samples were sectioned and evaluated for microleakage. RESULTS: One-way analysis of variance on ranks revealed no significant difference in leakage at both the dentin and enamel margins between the conventional and ART groups. The microleakage at the dentin margin, however, was significantly greater (P < .001) than at the enamel margins in the conventional group. CONCLUSION: Alternative restorative treatment with GIC provides enamel and dentin margins that show comparable marginal leakage to conventionally restored permanent teeth. For the conventional restorations, leakage at the dentin margins occurs to a significantly higher extent than at the enamel margins.     

The influence of matrix use on microleakage in Class 5 glass-ionomer restorations.

This in vitro study examined the relationship of matrix use to microleakage in class 5 Ketal-Fil glass-ionomer restorations. Class 5 glass-ionomer restorations were placed on the facial and lingual surfaces of 40 extracted human molars. The occlusal margin was located on enamel, and the cervical margin was located on cementum or dentin. Each tooth had one restoration placed with and without the aid of a soft metal matrix. Specimens were thermocycled (1234 cycles, 6 degrees C -60 degrees C, 30-second dwell time) and immersed in 5% methylene blue dye for four hours. The teeth were sectioned occlusogingivally through the center of each restoration, viewed with an optical microscope (X10), and each restoration was scored for dye penetration around the cavity walls. The enamel and cementum margins were scored separately for the extent of marginal leakage. No difference in leakage was found between restorations placed with or without a matrix (P > 0.05). Enamel restorations leaked significantly less than nonenamel margins, regardless of matrix use (P > 0.05).     

Influence of flowable liner and margin location on microleakage of conventional and packable class II resin composites

This in vitro study evaluated gingival wall microleakage in packable and microhybrid conventional composite restorations with and without a flowable composite liner. Each group was evaluated with gingival margins situated in both enamel and cementum/dentin. Two hundred and forty Class II cavities were prepared in extracted third molars, half with gingival margins in enamel and half with margins in dentin/cementum. In groups of 30, restoration was undertaken with packable alone (3M Filtek P60), conventional alone (3M Z250), packable plus flowable liner (3M Filtek Flow) and conventional plus flowable liner. All used 37% phosphoric acid etch and Scotchbond 1 (3M) as the bonding system. After restoration, the teeth were thermocycled (between 5 degrees C, 37 degrees C and 60 degrees C) 1,500 times, soaked in 0.1% methylene blue, sectioned and microleakage from the gingival margin scored. Statistical analysis was performed using Kruskal Wallis and Mann-Whitney U tests. There was no significant difference between systems in terms of leakage scores when gingival margins were situated in enamel (p=0.70). All restorations with margins in cementum/dentin leaked significantly more than those with margins in enamel (p<0.001). There was no significant difference between leakage scores of 3M Z250 and Filtek P60 with cementum/dentin gingival margins (p=0.68). Use of a flowable composite liner (3M Filtek Flow) against cementum/dentin was associated with increased microleakage (p<0.001). In this study, leakage scores suggest that gingival margins should be placed in enamel. The conventional and packable resin composites tested were not associated with differences in microleakage. Leakage data do not support the use of flowable resin composite linings in Class II resin composite restorations.     

Comparison of microleakage of three acid-base luting cements versus one resin-bonded cement for Class V direct composite inlays

STATEMENT OF PROBLEM: Demineralized dentin beneath set cement may adversely affect microleakage under fixed restorations. PURPOSE: Microleakage of direct composite inlays cemented with acid-base cements and a methyl methacrylate resin cement were evaluated to determine their effect on the integrity of the underlying hybridized dentin. MATERIALS AND METHODS: Sixty Class V box preparations (3 mm x 3 mm x 1.5 mm) were precisely prepared in previously frozen bovine teeth with one margin in enamel and another margin in dentin. Direct composite inlays (EPIC-TMPT) for each preparation were divided into 4 groups of 15 specimens each and cemented with 3 acid-base cements (control group): Elite, Ketac-Cem, Hy-Bond Carbo-Cem, and 1 adhesive resin cement: C&B Metabond. All specimens were stored in distilled water for 24 hours at 37 degrees C before immersion in 0.5% basic fuchsin for 24 hours. The dye penetration was measured on the sectioned specimens at the tooth-cement interface of enamel and cementum margins and recorded with graded criteria under light microscopy (Olympus Vanox-T) at original magnification x 50, 100, and 200. A Kruskal-Wallis and the Mann-Whitney test at P<.05 were used to analyze leakage score. RESULTS: All cementum margins of the 3 acid-base cements tested demonstrated significantly higher leakage scores than cementum margins for inlays cemented with the resin cement tested(P<.01). No leakage along the tooth-cement interface was found for inlays retained with the adhesive resin cement. CONCLUSIONS: Within the limitations of this study, the 3 acid-base cements tested exhibited greater microleakage at the cementum margins than did the adhesive resin cement that was tested.     

Influence of ZOE temporary restorations on microleakage in composite restorations

This study investigated the influence of zinc-oxide eugenol (ZOE) temporary restorations on microleakage in composite restorations. Class V cavities were prepared on the buccal surfaces of 32 freshly extracted, non-carious human premolars. The teeth were randomly divided into four groups of eight teeth. Specimens in Group 1 (control) received no temporary restoration. Group 2 and 3 specimens were covered with IRM (Type III ZOE cement) mixed at powder:liquid (P:L) ratio of 10g:1g and 10g:2g, respectively. Specimens in Group 4 were covered with poly-carboxylate cement (eugenol-free) mixed at a P:L ratio of 2.85g:1g. The temporary restorations were removed mechanically with an ultrasonic scaler after one week storage in distilled water at 37 degrees C. The preparations were washed and restored with Scotchbond Multi-Purpose Plus and Z100 according to manufacturers' instructions. The restorations were finished, thermally stressed for 400 cycles and subjected to dye penetration testing. Results were analyzed using Kruskal-Wallis and Mann-Whitney tests at a significance level of 0.05. At both enamel and dentin margins, the microleakage associated with Group 3 was significantly greater than for Groups 1, 2 and 4. For Groups 1 and 4, leakage at the dentin margins was significantly greater than in enamel margins. For the groups pretreated with IRM, no significant difference in dye penetration scores was observed between enamel and dentin. Pre-treatment with IRM mixed at a P:L ratio of 10g:2g significantly increased microleakage and is not recommended clinically.     

Microleakage of composite restorations bonded with three new dentin bonding agents.

This report evaluates the impact of two dentin bonding techniques on microleakage of Class V restorations bonded with three new dentin bonding systems. Forty-eight extracted human premolar and molar teeth were randomly assigned to four groups for bonding with EBS Bonding System (ESPE, Seefeld, Germany); Syntac Single-Component (Ivoclar-Vivadent, Schaan, Liechtenstein); Scotchbond 1 (3M Dental Products, St. Paul, Minnesota); and a control, Prime and Bond 2.1 (Dentsply, DeTrey, Konstanz, Germany). Cavities were cut in both the buccal and lingual surfaces. The coronal half of each preparation was in enamel, and the gingival half was in cementum or dentin. The cavities were restored with composite after the application of dentin bonding agents, using two different drying techniques for each material. The teeth were stored in distilled water for 6 days at 37 degrees C and then thermocycled. The restorations were examined microscopically for leakage, using Procion brilliant red as a marker. All groups showed microleakage at both the enamel and dentin margins. At the gingival margin, there was no significant difference between any of the experimental materials and the control for either wet bonding (Kruskal-Wallis: p = .8920) or dry bonding (Kruskal-Wallis: p .9973); or between the two techniques for each material (Mann-Whitney U in all cases p > .05). Scanning electron microscopic examination confirmed that the zones of microleakage, as indicated by dye penetration, were principally resincohesive failures within the collagen-rich hybrid layer. Three water-based bonding agents were unable to prevent microleakage at either the enamel or dentin margins of Class V cavities regardless of which bonding technique was employed. All systems behaved equally.     

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.     

Microleakage in class V gingiva-shaded composite resin restorations

The purpose of this study was to evaluate the microleakage in Class V cavities restored with a new gingiva-shaded microhybrid composite resin and with a conventional microhybrid composite resin using three different dentin bonding systems (DBS). Class V cavities were prepared in sixty freshly extracted human teeth with the incisal margin in enamel and the apical margin in dentin/cementum. Restored specimens, after thermocycling, were placed in 2% methylene blue solution for 24 hours. Longitudinal sections were obtained and studied with a stereomicroscope for assessment of the microleakage according to degree of dye penetration (scale 0-3). Data were analyzed with Kruskal-Wallis test and with Mann-Whitney U-test.IN THIS STUDY THERE WAS NO LEAKAGE IN ENAMEL: all the cavities showed no dye penetration at the incisal margins (located in enamel). None of the DBS used eliminated microleakage in apical margins (located in dentin or cementum): three-step total-etch and single-step self-etch were more effective in reducing microleakage in dentin margins when compared with two-step total-etch. This in vitro study concluded that microleakage in Class V cavities restored with the composite resins tested is similar.     

Influence of time and thermocycling on marginal sealing of several dentin adhesive systems.

This study evaluated the in vitro microleakage of six dentin adhesive systems. Triangle-shaped Class V cavities with coronal margin in enamel and gingival margin in cementum or root dentin were cut in the buccal surfaces of 90 non-carious single-root human teeth. These teeth were randomly assigned into six groups (n = 15) for the evaluation of six different dentin adhesive systems: One Step, Prime & Bond 2.0, Syntac Single, Single Bond, Optibond Solo and Syntac Sprint. The preparations were restored with Degufill Ultra composite and polished using the Enhance system. Each group was randomly divided into three subgroups (n = 5): samples of the first subgroup were immersed in 2% methylene blue solution for seven days; those of the second subgroup remained in a similar solution for 31 days; those of the third subgroup were thermocycled 500x at 5-55 degrees C and immersed in 2% methylene blue for seven days. All 90 teeth were then embedded in methacrylate and bucco-lingually sectioned; the dye penetration was evaluated using an 0-4 ordinal scale. All of the dentin adhesive groups showed minimal leakage at the enamel margins with increased leakage at the gingival margins. Optibond Solo showed the best outcomes among the dentin adhesives tested.     

Microleakage of capsulated glass ionomer cements

The purpose of this study was to compare marginal leakage in Class V preparations restored and finished within 20 minutes with two different capsulated and syringeable restorative glass ionomer cements. The materials were inserted and finished following manufacturer's specifications. Specimens were thermocycled 125x in fuchsin dye at 5 degrees C and 55 degrees C, mounted in acrylic and sectioned faciolingually. Microleakage was observed and rated on a scale of 0 to 3 at both enamel and cervical margins. The results of this study indicate that: 1) both materials exhibit marginal leakage at enamel and cervical margins, 2) no significant difference in microleakage was found between these materials, and 3) enamel margins leaked less than cementum/dentin margins with each material.     

Comparison of microleakage for three one-bottle and three multiple-step dentin bonding agents.

PURPOSE: This in vitro study compared the ability of several recently introduced 1-bottle adhesives to their preceding multiple-step dentin bonding agents in reducing microleakage around Class V composite restorations. MATERIAL AND METHODS: Facial and lingual Class V cavities were prepared in 48 molar teeth, which were randomly divided into 6 equal groups. Three groups used the fourth-generation multiple-step systems, and 3 used the fifth-generation single-bottle adhesives. All cavities were restored by composite and subjected to thermocycling and intermittent occlusal loading. After immersion in 0.5% basic fuchsin, the teeth were cut faciolingually in 5 consecutive sections and evaluated for dye penetration using a binocular stereomicroscope. RESULTS: There was no statistically significant difference in the degree of microleakage comparing the adhesive's generation and manufacturer and the location of the cavity margins. A significant interaction was found between margin location and manufacturer, which implied that the sealing capacity at the enamel and cementum margins was material-specific. CONCLUSION: Scotchbond Multi-Purpose and Single Bond adhesives provided the best seal for enamel margins, and One-Step and Optibond FL adhesives were best for cementum margins.     

Microleakage of direct and indirect composite restorations with three dentin bonding agents

This study evaluated the marginal sealing ability of direct and indirect (inlay) resin composite restorations with three dentin bonding systems. Forty-eight freshly extracted bovine incisor teeth were randomly assigned to four groups for bonding with Syntac Single-Component, Excite (Vivadent, Liechtenstein), ScotchBond Multi-Purpose Plus (3M Dental Products, St Paul, MN 55144, USA) and a control with no bonding agents. Class V cavities were cut in both buccal and lingual surfaces. The coronal half of each preparation was in enamel and the gingival half was in cementum or dentin. Half of the specimens in each group were restored with direct and the remainder with indirect technique. The teeth were stored in 37 degrees C water for 30 days, then thermocycled. After immersion in 0.5% basic fuchsin, the teeth were cut faciolingually and evaluated for dye penetration using a binocular stereomicroscope. There was no significant difference among the bonding systems for either the direct or indirect technique or between the two techniques used for each system, however, the indirect technique showed significantly (p = 0.001) less microleakage than the direct technique in control groups. All groups showed more leakage at the cementum margins except Excite with direct technique, where microleakage at the incisal and gingival margins was almost equal.     

Microleakage of Composite Restorations Bonded with Three New Dentin Bonding Agents

ABSTRACT: This report evaluates the impact of two dentin bonding techniques on microleakage of Class V restorations bonded with three new dentin bonding systems. Forty-eight extracted human premolar and molar teeth were randomly assigned to four groups for bonding with EBS Bonding System (ESPE, Seefeld, Germany); Syntac Single-Component (Ivoclar-Vivadent, Schaan, Liechtenstein); Scotchbond 1 (3M Dental Products, St. Paul, Minnesota); and a control, Prime and Bond 2.1 (Dentsply, DeTrey, Konstanz, Germany). Cavities were cut in both the buccal and lingual surfaces. The coronal half of each preparation was in enamel, and the gingival half was in cementum or dentin. The cavities were restored with composite after the application of dentin bonding agents, using two different drying techniques for each material. The teeth were stored in distilled water for 6 days at 37°C and then thermocycled. The restorations were examined microscopically for leakage, using Procion brilliant red as a marker. All groups showed microleakage at both the enamel and dentin margins. At the gingival margin, there was no significant difference between any of the experimental materials and the control for either wet bonding (Kruskal-Wallis: p .8920) or dry bonding (Kruskal-Wallis: p .9973); or between the two techniques for each material (Mann-Whitney U in all cases p > .05). Scanning electron microscopic examination confirmed that the zones of microleakage, as indicated by dye penetration, were principally resin-cohesive failures within the collagen-rich hybrid layer. Three water-based bonding agents were unable to prevent microleakage at either the enamel or dentin margins of Class V cavities regardless of which bonding technique was employed. All systems behaved equally.     

Effects of finishing/polishing techniques on microleakage of resin-modified glass ilonomer cement restorations

This study investigated the effect of finishing/polishing techniques on the microleakage of resin-modified glass ionomer restorations. Class V preparations were made on the buccal and lingual/palatal surfaces of freshly extracted teeth. The cavities on each tooth were restored with Fuji II LC (FT [GC]) and Photac-Fil Quick (PF [3M-ESPE]) according to manufacturers' instructions. Immediately after light-polymerization, gross finishing was done with eight-fluted tungsten carbide burs. The teeth were then randomly divided into four groups and finishing/polishing was done with one of the following systems: (a) Robot Carbides (RC); (b) Super-Snap system (SS); (c) OneGloss (OG) and (d) CompoSite Polishers (CS). The sample size for each material-finishing/polishing system combination was eight. After finishing/polishing, the teeth were stored in distilled water at 37 degrees C for one week. The root apices were then sealed with acrylic and two coats of varnish was applied 1 mm beyond the restoration margins. The teeth were subsequently subjected to dye penetration testing (0.5% basic fuchsin), sectioned and scored. Data was analyzed using Kruskal-Wallis and Mann-Whitney U tests at a significance level of 0.05. Results of statistical analysis were as follows: Enamel margins: PF-OG相似文献   

Effect of dentin deproteinization on microleakage of Class V composite restorations

The role of the collagen fibers in dentin adhesion has not clearly been established. Therefore, this laboratory study evaluated the microleakage at resin-dentin and resin-enamel interfaces of Class V composite restorations after etching enamel and dentin with phosphoric acid (H3PO4) or after etching with H3PO4 followed by deproteinization with 5% sodium hypochlorite (NaOCl) to prevent the formation of a hybrid layer. Ten extracted human molars were used to prepare standardized Class V cavities on both buccal and lingual surfaces. The teeth were randomly divided in two groups: 1) Class V cavities that were etched with H3PO4 for 15 seconds; b) Class V cavities that were etched with H3PO4 for 15 seconds followed by collagen removal with 5% NaOCl for two minutes. The cavities were restored using the Prime & Bond 2.1 bonding system and TPH resin composite. The specimens were stored in water for 24 hours at 37 degrees C and thermocycled 500 times between water baths kept at 5 degrees C and 55 degrees C. After thermocycling, specimens were immersed in a 0.5% aqueous solution of basic fuchsin for 24 hours. Three longitudinal sections of each restoration were obtained and examined with a stereomicroscope for qualitative evaluation of microleakage. The data were statistically analyzed by Mann-Whitney U and Wilcoxon matched pairs signed ranked tests. Extra specimens were analyzed with the scanning electron microscope (SEM). Occlusal margins (enamel margins) resulted in statistical lower degree of leakage than gingival margins (dentin/cementum margins) in both treatment groups. For each type of margin, there were no statistically significant differences between the etched and the etched and deproteinized groups. Under the SEM, occlusal surfaces showed no detachment between enamel and dentin, while dentin/cementum resulted in gap formation.     

Microleakage and SEM interfacial micromorphology of amalgam restorations using three adhesive systems

OBJECTIVE: This study evaluated the microleakage and interfacial micromorphology of Class V cervical amalgam restorations lined with OptiBond, AElitebond, or Panavia 21. METHODS: Unlined amalgams served as control. Cavities were treated with each dentin bonding system according to the manufacturers' instructions and restored with Tytin non-gamma 2 spherical amalgam. After one week of storage in tap water at 37 degrees C, the specimens were thermocycled (1000 cycles, 6-60 degrees C, 30s dwell time). Microleakage was assessed by means of basic fuchsin dye penetration and recorded according to an ordinal scale. RESULTS: None of the systems tested in this study completely eliminated microleakage. Kruskal-Wallis one-way ANOVA and Mann-Whitney U test found that on the occlusal wall, Panavia 21 and the control group had the least leakage (P<0.05). No statistically significant differences were found at dentin margins (P>0.05). Wilcoxon matched pairs signed rank test found that Panavia 21 and the control group had less leakage at the occlusal than at the dentin margins (P<0.05); when AElitebond and OptiBond groups were evaluated, microleakage at the enamel and at the dentin margins was similar for each group. With the adhesive systems, perhaps the hydrophilic bonding agents incorporated the dye during specimen immersion and/or sectioning. CONCLUSIONS: The use of adhesives may not be as worthy as resin cements for sealing and bonding amalgam restorations to enamel and dentin.     

The effect of thermocycling on microleakage of several commercially available composite Class V restorations in vitro

STATEMENT OF THE PROBLEM: Microleakage is a major factor contributing to the occurrence of secondary carious lesions around composite restorations. PURPOSE OF STUDY: This in vitro study investigated the effect of thermocycling on microleakage of several composite Class V restorations. MATERIAL AND METHODS: One hundred twenty molars were randomly distributed into 6 groups of 20 teeth. Class V preparations were made in the buccal and lingual surfaces of each tooth and restored in bulk by use of 6 composites (Arabesk, Silux-Plus, Solitaire 2, Durafill VS, Charisma, and Renew) according to the manufacturers' recommendations. The teeth were stored in distilled water at room temperature for 24 hours. The teeth in each group were divided randomly into 2 subgroups: (a) thermocycled for 500 cycles between 5 degrees and 55 degrees C with a dwell time of 30 seconds, (b) no thermocycling treatment. All restored teeth were immersed in 1% methylene blue dye for 4 hours and sectioned buccolingually with a diamond wheel. Dye penetration was scored by use of a stereomicroscope at original magnification x4. The generalized linear models statistical analysis was used (alpha=.05). RESULTS: The preparation margins (enamel/dentin) and thermocycling had a significant effect on microleakage (P=.0351, P<.0001, respectively); the type of material had no significant effect (P=.1689). CONCLUSIONS: Thermocycling significantly increased the microleakage (P<.0001). The overall microleakage at the enamel margins was significantly less than at the dentinal margins (P=.0351).     

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.     

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.