Microleakage of posterior composite restorations

Several composite restorative resins have recently been introduced for use in posterior teeth. A number of dentin bonding agents are commercially available for use in conjunction with composite restorative resins. The objective of this in vitro study was to evaluate the microleakage of Class II MOD preparations in extracted human mandibular molar teeth restored with a chemically-activated posterior composite resin (P 10) and a visible light-cured composite resin (P 30) used in conjunction with a low viscosity bonding resin (Enamel Bond) and a dentin bonding resin (Scotchbond), respectively. The restored teeth were subjected to 100 complete temperature cycles in an aqueous ⁴⁵CaCl₂ solution between 5°C and 55°C and the microleakage evaluated from autoradiographs. Microleakage was observed at the cervical aspects of all the restorations. The results of this in vitro study suggest that microleakage may occur at these sites of posterior composite restorations.     

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.     

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.     

Marginal Leakage of a New Adhesive Restorative System: A Preliminary In Vivo Investigation

The efficacy of newly developed adhesive restorative materials is commonly described by in vitro test results such as bond strength and microleakage data. Due to the inconsistency often found between in vitro testing and in vivo performance, the purpose of the present investigation was to restore teeth scheduled for extraction in vivo with an experimental restorative bonding system and to evaluate the microleakage of the restorations by common laboratory techniques following extraction after 3 months of clinical service. Two restorations were placed in each of seven anterior teeth, one in the middle of the labial enamel portion and the other labially extending over the cementoenamel junction (CEJ). Six of the seven fillings completely surrounded by enamel showed no microleakage. However, two of the restorations crossing the CEJ revealed microleakage originating from the cervical margins. In spite of the small number of fillings assessed, the experimental enamel-dentin adhesive compound tested is preliminarily considered a promising new system.     

The effect of pulse activation on microleakage of a 'packable' composite resin and two 'ormocers'

The purpose of the study was to examine the effect of pulse polymerization on microleakage of one packable composite resin and two organically modified ceramics (ormocers), within a high C-factor preparation. Class-V cavity preparations with occlusal margins in enamel and gingival margins in dentin were prepared on 60 freshly extracted premolars or molars. Teeth were randomly assigned to 12 experimental groups (five teeth each) representing the different restorative systems, mode of polymerization and thermal cycling test. Three groups of 20 teeth each were restored with one of the following restorative systems: Scotch bond 1/Filtek P 60, Admira bond/Admira, Etch&Prime 3.0/Definite. 10 restorations of each restorative system (two experimental groups) were conventionally polymerized, whereas the other 10 restorations were polymerized with a pulse program. The specimens were stored in double-distilled water at 37 degrees C for 24 h. Ten restorations from each restorative system (30 restorations, half of the specimens) were thermocycled, the other 30 restorations were kept in double-distilled water at 37 degrees C for 24 h. Then all 60 restorations stained with dye, sectioned and scored for microleakage. Results showed that there were no significant differences (P > 0.05) among the materials with respect to microleakage scores. The experimental groups that were conventionally polymerized revealed significantly more microleakage (P < 0.05) after thermal cycling than all the other groups. The gingival microleakage was significantly more (P < 0.05) than occlusal in conventionally polymerized, thermocycled experimental groups.     

The effect of polishing systems on microleakage of tooth-coloured restoratives. Part 2: composite and polyacid-modified composite resins

The purpose of this in vitro study was to investigate the effect of polishing systems on the microleakage of composite and polyacid-modified composite resins. Class V cavities were prepared at the cemento-enamel junction of 80 freshly extracted posterior teeth. The prepared teeth were randomly divided into two groups and restored with conventional or polyacid-modified composite resins. The restored teeth were stored in distilled water at 37 degrees C for 1 week after removal of excess restorative with diamond finishing burs. The restored teeth were then divided into four groups of ten and finished/polished using the following systems: Two Striper micron finishing system (MFS), Sof-Lex XT (Sof-Lex), Enhance composite finishing and polishing system (Enhance), and Shofu composite finishing kit (Shofu). The finished restorations were subjected to dye penetration testing. Results showed that the microleakage resistance at both enamel and dentin margins of composite and polyacid-modified composite resins are not significantly affected by the different polishing systems.     

Microleakage of compomer class V restorations: effect of load cycling, thermal cycling, and cavity shape differences

STATEMENT OF PROBLEM. Microleakage is an important problem with direct filling restorations and an understanding of the factors that contribute to it is of critical importance. PURPOSE. This study investigated the effect of thermal and occlusal load cycling, and limited cavity preparation on microleakage of compomer Class V restorations in vitro. MATERIAL AND METHODS. Class V cavities were randomly prepared on the buccal and lingual surfaces of 32 recently extracted molars and premolars and restored with Dyract compomer restorative system as per the manufacturer's directions. Teeth were randomly assigned to 1 of 4 treatment groups with 8 teeth in each group: (I) thermocycling only; (II) load cycling only; (III) both thermocycling and load cycling; and (IV) no treatment. All teeth were then immersed in 2% basic fuchsin solution for 24 hours. Dye penetration was measured linearly using color photographic prints. ANOVA, comparisons between means, and correlation were used to analyze the results. RESULTS. Thermocycling and cavity preparation had a significant effect on microleakage, but load cycling did not. Occlusal margins leaked more than the gingival margins. CONCLUSION. Class V restorations demonstrated increased microleakage under the conditions of thermal cycling and nonretentive cavity design. More microleakage occurred at occlusal margins than at gingival margins. The effect of load cycling is complicated by considerations of the types of stresses applied and the restorative material response to such stresses.     

Microleakage of glass ionomer/composite resin restorations: A laboratory study. 1. The influence of glass ionomer cement

Acid-etching of enamel margins, often combined with bevelling and use of a low viscosity resin, has resulted in improved sealing of composite restorations. When enamel is absent and margins involve dentine or cementum, microleakage is more often observed. The use of glass ionomer cement, as both a restorative material and as a base combined with a veneer of composite resin, has been advocated as a means of minimizing microleakage where margins are placed in dentine or cementum. Four restorative techniques incorporating glass ionomer cement were used, in vitro, to restore cervical cavities. After thermal cycling, dye penetration was scored along occlusal and gingival margins. In all instances the gingival margin exhibited a less reliable seal than the occlusal margin. The sandwich restorations produced a superior seal at both occlusal and gingival margins when compared with glass ionomer restorative cement.     

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.     

Marginal integrity of large compomer Class II restorations with cervical margins in dentine

OBJECTIVES: The aim of the present study was to investigate the marginal integrity of total-bond Dyract AP restorations in large Class II restorations with cervical margins in dentine. The efficacy of a new non-rinse conditioner and the effect of beveling the enamel margins were also studied. METHODS: Large MOD cavities with cervical margins located 1mm below the CEJ were prepared in 48 extracted human molars. Six groups (n=8) were filled using a total-bond technique with Spectrum TPH or Dyract AP or a sandwich technique with Dyract in combination with Spectrum TPH. For Dyract AP total-bond restorations, a new non-rinse conditioner was tested vs. a total-etch with 36% phosphoric acid in beveled and butt-joint cavities. After water storage for 21 days and thermocycling (2000x, 5-55 degrees C), replicas were produced for quantitative marginal analysis in the SEM. Afterwards, teeth were immersed in 0.5% basic fuchsin for 24h and dried. Percent dye penetration over the total margin length was analysed in three layers using a sequential grinding technique. Statistical analysis was performed with non-parametric tests and the Bonferroni correction for multiple comparisons at p<0.05. RESULTS: All restoration types showed microleakage. On cervical margins in dentine, Dyract AP restorations showed better marginal adaptation than Spectrum TPH total-bond restorations (marginal openings (MO), median 33.8 vs. 79.6%), but were inferior to Dyract/Spectrum TPH sandwich restorations (MO: 0. 0%). The non-rinse conditioner improved the marginal adaptation of Dyract AP restorations in dentine (MO: 4.7 vs. 38.4%, p=0.0206 for beveled cavities, 12.2 vs. 33.8%, p=0.0238, for butt-joint cavities) and yielded similar results in enamel margins provided that enamel margins were beveled. Beveling of enamel significantly reduced the occurrence of enamel microcracks. CONCLUSIONS: The use of a non-rinse conditioner in combination with Dyract AP may improve the marginal adaptation of Class II restorations compared to composite restorations. The sandwich technique with Dyract results in better marginal adaptation in cervical dentine compared to all other restorative techniques tested in this study. However, microleakage cannot predictably be prevented with the sandwich technique.     

Reducing microleakage in composite resin restorations: an in vitro study

The purpose of this in vitro study was to evaluate the effect of a resin lining on microleakage around composite resin restorations. Standard slot cavities were prepared on the approximal surfaces of 48 extracted human molar teeth. The cavities were restored with two conventional or two condensable composite resins, placed with or without a flowable composite resin lining. The teeth were subjected to thermal stress and immersed in dye solution. Dye penetration was viewed with both a stereomicroscope and a scanning electron microscope. Flowable resin lining material under condensable composites may be beneficial in reducing microleakage around cervical margins.     

Assessment of marginal leakage around Class II composite restorations in retrieved primary molars

The aim of the present investigation was to evaluate, by means of dye penetration, the microleakage around Class II composite restorations, in retrieved primary molars that functioned in the mouth for at least one year. The experimental material consisted of 13 exfoliated primary molars that had been restored with Herculite (Kerr Corporation, Romulus, Michigan 48174 USA) at least one year previously, utilizing an incremental or a bulk filling technique. The retrieved teeth were insulated with utility wax and nail polish, immersed in 2% basic fuchsin, embedded in acrylic resin, and ground off to various depths. The marginal leakage was assessed according the degree of dye penetration at the occlusal and cervical margins. No difference was observed between the two filling techniques. In most teeth, no leakage at the occlusal margins was observed; minimal leakage, limited to the enamel, was observed at the occlusal margins of two teeth, one of each filling technique. Severe penetration was evident at the cervical margin of three restorations, two of them filled incrementally and the third using the bulk technique. Mild to moderate penetration was observed at the cervical margin in the majority of the other restorations. It was concluded that an incremental filling technique could not eliminate microleakage at the cervical margins of Class II composite restorations.     

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.     

The effect of flowable resin composites as gingival increments on the microleakage of posterior resin composites

Microleakage has been a major concern in restorative dentistry. The curing contraction of composites still presents a problem with controlling microleakage and postoperative sensitivity. This study investigated the effect of flowable materials on gingival microleakage of microhybrid and packable resin composite restorations. Ninety Class II cavities with cervical margins 1 mm below the CEJ were prepared in 45 extracted human premolars. The teeth were randomly divided into three groups (n=15). In each group, one side of each tooth was restored incrementally with respective composites-SureFil, Filtek P60 and Tetric Ceram; whereas, on the other side, flowable materials-Dyract Flow, Filtek Flow or Tetric Flow-were placed respectively as a 1-mm thick gingival increment before the resin composite restoration. The restored teeth were stored for one week in distilled water at 37 degrees C, thermocycled between 5 degrees C and 55 degrees C and immersed in 0.5% basic fuchsin for 24 hours. Dye penetration was evaluated using a stereomicroscope at 10x magnification. The data were analyzed statistically by Kruskal-Wallis analysis of variance and Mann-Whitney U-tests. The effect of flowable increments on reducing the gingival microleakage was found to be statistically significant for all restorative materials tested (p<0.05).     

Microleakage in the proximal walls of direct and indirect posterior resin slot restorations

This study compared the degree of microleakage in the proximal walls of direct and indirect resin slot restorations in relation to the types of dentin bonding systems and the location of gingival margins. Two Class II slot preparations were prepared and restored in each of 60 extracted human molars using direct (Filtek Supreme) and indirect (Tescera ATL) restorative resin materials. Various types of dentin bonding systems, including self-etching (OneStep Plus/Tyrian SPE, iBond, Xeno III) and etch and rinse systems (All-Bond 2, Prime & Bond NT) were used to restore the prepared teeth. The gingival proximal wall was placed apical to the cementoenamel junction (CEJ) in 1 proximal box and coronal to the CEJ in the other. The specimens were stained and evaluated for microleakage using a digital imaging and analysis system. Significant differences were found in the degree of microleakage observed in the various restorative groups. In general, the group restored with indirect resin had less microleakage than the direct resin groups. Factors, such as type of dentin bonding system and location of gingival margins, exert a substantial influence on the degree of microleakage that occurred along the walls of proximal resin restorations.     

Microleakage in Class II composite restorations with margins below the CEJ: In vitro evaluation of different restorative techniques

Objectives: The purpose of this in vitro study was to evaluate the microleakage in “deep” Class II composite restorations with gingival cavosurface margin below the CEJ (cemento-enamel junction) and restored with different techniques. Study Design: Fifty human teeth were used. In each tooth two standardized Class II slot cavities (on mesial and on distal surfaces) were prepared: the buccolingual extension of the cavities was 4 mm; the gingival wall was located in dentin/cementum (2 mm beyond the CEJ). The prepared teeth were randomly assigned to 5 experimental groups (of 10 specimens and 20 cavities each) and restored. Group 1: Filtek TM Supreme XTE Flowable (3MESPE) + Universal Filtek Supreme XTE (3MESPE), Group 2: GrandioSO Heavy Flow (Voco) + GrandioSo (Voco), Group 3: SDR™ (Dentsply Caulk) + Esthet-X® HD (Dentsply Caulk), Group 4: SonicFill (Kerr), Group 5: Grandio (Voco). After thermocycling, the specimens were immersed in a 0.5% basic fuchsine dye solution and incubated at 37°C for 24 hours. The teeth were subsequently sectioned mesiodistally. All specimens were examined at 25× in a stereomicroscope and standardized digital images were obtained. Dye penetration was measured from gingival margins. Results: The results demonstrated no significant leakage differences between Group 4 and Group 5, that both showed significantly higher frequency distribution of Score 0. Group 2 and Group 3 showed a significant prevalence of Score 1, whereas Group 1 showed significantly higher frequency of Score 2. Conclusions: None of the restorative techniques tested completely eliminated microleakage dye penetration in dentin margins; marginal adaptation in Class II composite restorations with gingival wall below the CEJ varied in both substrates and from different restorative techniques used. Key words:Microleakage, Class II composite restorations, CEJ.     

The effect of polishing systems on microleakage of tooth coloured restoratives: Part 1. Conventional and resin-modified glass-ionomer cements

The purpose of this in vitro study was to investigate the effect of polishing systems on the microleakage of conventional and resin-modified glass-ionomer cements. Class V cavities were prepared at the cemento-enamel junction of 80 freshly extracted posterior teeth. The prepared teeth were randomly divided into two groups and restored with conventional or resin-modified glass-ionomer cements. The restored teeth were stored in distilled water at 37 degrees C for 1 week after removal of excess restorative with diamond finishing burs. The restored teeth were then divided into four groups of 10 and finished and polished using the following systems: Two Striper MFS; Sof-Lex XT; Enhance Composite Finishing and Polishing System; Shofu Composite Finishing Kit. The finished restorations were subjected to dye penetration testing. Results showed that the microleakage at dentin margins of conventional glass-ionomer cements and enamel margins of resin-modified glass-ionomer cements are significantly affected by the different polishing systems.     

Effect of centripetal and incremental methods in Class II composite resin restorations on gingival microleakage

AIM: The aim of this study was to evaluate the microleakage at gingival margins below the cementoenamel junction (CEJ) of Class II composite restorations using various placement techniques. METHODS AND MATERIALS: Sound human maxillary premolars were selected. Eighty slot-style cavities on the mesial or distal surfaces were prepared with the cervical margins located apical to the CEJ. The specimens were divided into two groups based on the restorative technique utilized (centripetal or incremental). Each group was then categorized into two subgroups according to the type of matrix used resulting in a total of four experimental groups as follows: IP=Incremental and Palodent matrix, IT = Incremental and Transparent matrix, CP= Centripetal and Palodent matrix, and CT = Centripetal and Transparent matrix. Following restoration with a total etch adhesive (Single Bond) and a resin composite (Z100), the teeth were thermocycled. Then specimens were immersed in 0.5% basic fuchsin dye for 24 hours at a temperature of 37 degrees C. Sectioned restorations were examined under a stereomicroscope (40X magnification), and the extent of the microleakage was scored and recorded. Data were analyzed using the Kruskal-Wallis non-parametric statistical test (P=0.05). RESULTS: In the four groups of the study no significant differences in the mean rank of microleakage were observed (p>0.05). CONCLUSION: When the gingival margin was located on cementum, the kind of matrix and filling technique did not reduce the microleakage.     

Effect of various surface protections on the margin microleakage of resin-modified glass ionomer cements

STATEMENT OF PROBLEM: Because conventional glass ionomer cements are moisture sensitive, a surface coating is recommended during the initial setting stage. It is unknown whether resin-modified glass ionomer cements also need surface protection. PURPOSE: This study investigated the effect of various surface protections on microleakage with Class V resin-modified glass ionomer restorations. MATERIAL AND METHODS: Forty extracted molars with buccal and lingual Class V cavity preparations were restored with a resin-modified glass ionomer (Fuji II LC). The occlusal margin of each restoration was on enamel and the cervical margin on dentin. After immediate finishing and polishing, the teeth were divided into 4 groups according to the following surface protection treatments: group I, unprotected; group II, Fuji varnish; group III, resin adhesive; and group IV, acid etching and resin adhesive. After these procedures, all teeth were stored in isotonic saline for 24 hours, thermocycled 1500 times at 5 degrees C to 60 degrees C, and soaked in dye solution for 24 hours. The teeth then were longitudinally sectioned and observed under a stereomicroscope. The degree of dye penetration was recorded and analyzed with the Kruskal-Wallis and Mann-Whitney tests (P<.05) RESULTS: None of the 4 groups demonstrated complete margin sealing at either the occlusal or cervical margins. Groups II and III displayed the least microleakage at cervical margins; a significant difference existed between groups I and III (P=.034). Compared with the other 3 groups, group IV showed significantly greater microleakage at the cervical margins. CONCLUSION: Although resin-modified glass ionomers can be finished immediately, they remain moisture sensitive. Within the limitations of this study, the results suggest that resin adhesive should be used as a surface protection to reduce margin microleakage of resin-modified glass ionomer restorations.     

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.