Microleakage Of Composite Resin Restorations Research Articles

Effect of at-home and in-office bleaching on microleakage of class V composite resin restorations using different types of universal adhesives: An in vitro study.

When bleaching agents contact dental structures, they act on restorative materials and adhesive interfaces. This study investigated the effect of "at-home" and "in-office" bleaching on the microleakage of composite resin restorations performed with different universal adhesives in self-etch and etch-and-rinse modes. Class V cavities were prepared in 132 premolars. The samples were divided into four groups (n=33). All Bond Universal adhesive was used in the first and second groups, and G-Premio Bond adhesive was used in the third and fourth groups. The total-etch mode was used in the first and third groups, and the self-etch mode was used in the second and fourth groups. The samples were divided into three subgroups (n=11). In the first subgroup, home bleaching was used, and in the second subgroup, office bleaching was used. In the third subgroup, bleaching was not performed. The specimens were examined under a stereomicroscope for microleakage. Ordinal regression analysis was applied (P<0.05). The adhesive type, application method, and margin type significantly affected microleakage (P<0.05). The amount of microleakage in All Bond Universal adhesive was significantly higher than in G-Premio Bond adhesive. The chance of microleakage in the self-etch mode was almost twice as high as in the etch-and-rinse mode. The bleaching method did not significantly affect microleakage (P>0.05). Based on the results of the microleakage test, bleaching after composite resin restorations did not significantly affect the microleakage of Class V restorations.

Effect of Chlorhexidine and Ozone Gel on Microleakage and Shear Bond Strength of Dentin Bonding Agents in Composite Resin Restorations of Primary Teeth

Aim: This study aimed to investigate the effects of two antimicrobial agents on shear bond strength and microleakage of composite resin restorations in primary teeth. Methods: Sixty extracted primary molars and canines were assigned to three different groups according to the dentin surface pretreatment (2% chlorhexidine gluconate gel, ozone gel, and control group) and two subgroups (sound and caries-affected dentin) for shear bond strength tests. For the microleakage test process, a class V cavity was prepared on the buccal surface of the teeth and restored with composite resin. Then, all the teeth were cut buccolingually. The depth of stain penetration in each specimen was measured separately according to the scale. The data have been analyzed using SPSS 24 software. Results: In both sound and caries-affected dentin, ozone gel exhibited higher shear bond strength than chlorhexidine gel and the control group (P&lt;0.001). Chlorhexidine gel had no significant effect on the shear bond strength of sound dentin (P=0.561), but it reduced it in the caries-affected dentin (P&lt;0.001). With both disinfectants, the shear bond strength of the caries-affected dentin was significantly lower than that of the sound dentin. The application of chlorhexidine gel to caries-affected dentin resulted in more microleakage than sound dentin. In addition, the amount of microleakage in the ozone gel group was similar in both types of dentin. Conclusion: In both sound and caries-affected dentin, ozone gel was associated with higher shear bond strength than chlorhexidine gel; furthermore, chlorhexidine increased microleakage and ozone gel decreased it.

Effect of Er,Cr:YSGG and Nd:YAG Lasers on Microleakage of Composite Resin Restorations Using Universal Adhesives

Background: Clinical long-term success of bonded restorations is depended to reduce marginal microleakage and the laser application with combination of new bonding systems may play positive role. The aim of this study was comparative evaluation of Er,Cr:YSGG and Nd:YAG lasers effect on microleakage of class V composite resin restorations using several universal adhesives. Methods: In this in vitro study, standard class V cavities were prepared on both lingual and buccal surfaces of 72 intact premolar teeth. For evaluation of microleakage, the cavities were divided into 9 groups according to conditioning method (n=15): G1: G-Premio Bond [GP]; G2: Scotchbond Universal Adhesive [SU]; G3: All-Bond Universal [AB]; G4: GP+Nd:YAG Laser; G5: SU+Nd:YAG Laser; G6: AB+Nd:YAG Laser; G7: GP+Er,Cr:YSGG Laser; G8: SU+Er,Cr:YSGG Laser; and G9: AB+Er,Cr:YSGG Laser. The cavities were filled with composite resin and then subjected to thermocycling, placed in methylene blue solutions, embedded in resin blocks and vertically cut in the bucco­lingual direction. The microleakage in occlusal and gingival margins was defined as linear penetration of methylene blue and determined with a stereomicroscope to assign microleakage scores using a four­point scale. Data were analyzed by using SPSS software and Kruskal-wallis and Mann-Whitney U tests. Results: Microleakage scores had statistically significant different before and after laser irradiation in dependent to the adhesive used (P&lt;0.05) but there were no significant different between Nd:YAG and ER,Cr:YSGG laser, also between different universal adhesives (GP, SU, AB). The results showed that total microleakage scores of occlusal margins had significant statistical different in comparison with gingival margins (P&lt;0.001). Conclusion: The results indicate that Nd:YAG and Er,Cr:YSGG lasers irradiation, after using the investigated universal adhesives, had a positive effect on reducing the microleakage of composite Class V restorations. The microleakage rate was shown to be independent of adhesives and lasers type used in this study.

Microleakage Study of a Bulk Fill over an Uncured Adhesive System

This study aimed to evaluate and compare the microleakage of composite resin restorations under a total-etch adhesive system applied with two different techniques, with and without cure. Cavities were made on the buccal surface of twenty-six intact teeth and subsequently restored with bulk-fill flow composite resin (SDR®® flow+) and conventional resin (Spectra™ ST HV). Two experimental groups were created, one where the total-etch adhesive (Prime &amp; Bond Active®) was cured and another where the adhesive was not cured before placing the flowable resin. Two control groups were also created, negative and positive. After the restorations were finished the, teeth were submerged in a solution of sodium pertechnetate (99mTcNaO4) for 3 h to evaluate the microleakage. The results showed more infiltration of radioisotopes characterized by the highest total count values of microleakage in group 1 (cured adhesive) and in the positive control. Group 2 (noncured adhesive) and the negative control showed lower values. We therefore considered that these groups were similar since their p-value was less than 0.05, with no statistically significant difference. Group 4 showed a statistically significant increase in relation to group 3 (p = 0.027). We concluded that the method of bulk-fill composite resins with noncured adhesive agents can have a positive effect on the longevity of bond strengths, with reduced microleakage.

In vitro comparison of Biodentine and Riva LC interfaces with cervical dentin and Filtek Z350 in posterior class II open sandwich restorations

Class II open sandwich restorations are routinely performed with resin-modified glass ionomer cement as a dentin substitute and with composite resin as an enamel substitute. Biodentine™ is a new calcium silicate-based material. Various authors have evaluated the microleakage of composite resin restorations, where different resin-modified glass ionomer cements and Biodentine, used as a dentin base, were compared in class II open sandwich restorations. The aim of this study was to evaluate and to compare in vitro the sealing ability of Biodentine™ and Riva LC with cervical dentin and Filtek Z350 in posterior proximal restorations using the dye penetration test.

Effect of laser and light emitting diode bleaching techniques on micro-leakage of dental composite postoperatively using two different bonding systems in vitro study

Background and objective: Aesthetics is mostly a subjective perception that varies from individual to individual. The main objective of this study was to evaluate and compare the effects of LASER and light emitting diode bleaching techniques on the micro-leakage of composite resin restorations that were bonded with fifth and seventh adhesive bonding generations. Methods: Standardized cavity preparations were performed on 60 maxillary premolars and samples were divided into three groups according to the two adhesive systems (fifth and seventh) generation. After cavities were restored with two different adhesive systems and restored with composite resin, they were submitted to thermo-cycling procedures. Teeth were divided into six sub-groups according to the bleaching systems (control, in-office bleaching by light emitting diode (LED), LASER-activated in-office bleaching). After the bleaching procedure, teeth were evaluated for marginal leakage. All data were analyzed using the Mann-Whitney U and Kruskal-Wallis tests (p < 0.05) Results: The results of the present study showed that the control group presented lower micro -leakage values compared with the groups treated with bleaching agents. When the scores of micro-leakage of the six subgroups were compared, the differences among the groups were found to be statistically significant (p < 0.001). there was no significant difference found between the adhesive systems after treatment with the same bleaching techniques. Conclusion: Under the conditions of this study, micro-leakage of composite resin restorations differs according to the bleaching techniques used with no significant difference was found between the adhesive systems, and restorations post bleaching procedure was necessitate replacing by the clinician due adverse effects on tooth restoration interface.

Effect of Caries Detecting Dye on Microleakage of Composite Resin Restorations Bonded with Total-etch and Self-etch Adhesive Systems

Introduction: Caries detecting dyes are solutions employed to differentiate the infected portion of carious dentin from the remineralizable affected dentin. However, it is important that these agents should not interfere with the adhesion of permanent restorative materials. Aim: The purpose of this study was to evaluate the effect of caries detecting solution on microleakage of composite resin restoration bonded with two adhesive systems. Materials and Methods: Class V cavity of standardised dimension was prepared on forty intact extracted molars. Out of this, 10 teeth each were randomly selected for the four study groups. Group 1: composite restoration after etch and rinse technique without any prior exposure to caries disclosing solution; Group 2: placement of the restoration as mentioned in group 1 after exposing the cavity with caries detecting solution; Group 3: cervical restoration with composite after the use of self-etch adhesive system, with no exposure to caries detecting dye; Group 4: Similar to group 3 except that caries disclosing agent was applied onto the class V cavity before the placement of the composite restoration. The amount of dye penetrated was evaluated using fluorescent microscope. The microleakage scores were recorded and data obtained were subjected to statistical analysis using the chi-square test. Results: No significant difference was detected between the groups (p>0.05). However, Group 3 (self-etch without dye) showed the least percentage of microleakage with none of therestorations showing grade 3 leakage score. Conclusion: All study groups showed microleakage, but there was no statistically significant difference between the leakage scores. However, the highest leakage was seen in the total etch group where caries detecting dye was used.

Effect of bromelain enzyme on the microleakage of composite resin restorations after external tooth bleaching: An in vitro study.

Aims:The aim of this study is to evaluate in vitro the effect of application of bromelain enzyme on the microleakage of composite resin restorations after external tooth bleaching using spectrophotometric evaluation.Subjects and Methods:Buccal Class V cavities were prepared on the surface of fifty intact premolars, which were randomly divided into five groups. All cavities were filled with composite resin. Group I: Teeth were not bleached but restored (n = 10). External bleaching with 35% hydrogen peroxide was carried out for the rest of the specimensGroup II: Cavities were restored immediately after bleaching (n = 10)Group III: Cavities were restored after a delay of 3 weeks (n = 10)Group IV: Cavities were treated with sodium ascorbate after bleaching and then restored (n = 10)Group V: Cavities were treated with bromelain enzyme solution after bleaching and then restored (n = 10). Microleakage was assessed by the dye extraction method using a spectrophotometer. Statistical Analysis Used:The data were analyzed statistically by comparison of mean microleakage and post hoc test using SPSS 2.0 software.Results:Group I displayed the least amount of microleakage, whereas Group II showed the greatest amount of microleakage (P < 0.05). Groups III, IV, and V showed a significantly lower amount of microleakage compared to Group II (P < 0.05). There was no statistically significant difference between Groups IV and V.Conclusions:Microleakage increased significantly after external bleaching with 35% hydrogen peroxide, and decreased when the bleached teeth were treated with antioxidants. Ten percent bromelain enzyme was effective in decreasing microleakage; however, its efficacy was similar to 10% sodium ascorbate.

The Influence of a Hemostatic Agent on Adhesion Strength and Microleakage of Composite Resin Restorations

The Influence of a Hemostatic Agent on Adhesion Strength and Microleakage of Composite Resin Restorations

Marginal microleakage of composite resin restorations with surface sealant and bonding agent application after finishing and polishing

Microleakage at the marginal area of composite resin restorations can lead to discoloration and secondary caries. Performing rebonding after finishing and polishing can reduce microleakage of composite resin restorations. This study aimed to analyze the marginal microleakage of composite resin restorations after rebonding with a surface sealant and a bonding agent. Cavity preparation was performed on the buccal side of 60 human premolar teeth (3 mm in diameter and 2 mm in depth). Samples were randomly divided into two groups for rebonding with the different materials. Group 1 samples were rebonded with the surface sealant, whereas group 2 samples were rebounded with the bonding agent. Microleakage was measured using 1% methylene blue after thermocycling. Lesser microleakage was seen in group 1 than in group 2, with a statistically significant difference between the two groups (p < 0.05). Rebonding with a surface sealant can reduce marginal microleakage of composite resin restorations better than rebonding with a bonding agent.

Microleakage of Composite Resin Restorations Using a Type of Fifth and Two Types of Seventh Generations of Adhesive Systems: A Comparative Study

Introduction: In recent dentin adhesive systems etching of enamel/dentin are achieved simultaneously. The objective was to evaluate the microleakage of composite restorations using Single Bond2 (5th generation), Clearfil S3 Bond and G Bond (7th generation). Methods: Class V cavities were prepared on 45 extracted intact premolars with gingival margins at the cementoenamel junction and they were randomly divided into 3 groups (n=15) based on the type of adhesives: Single Bond2 (5th generation), Clearfil S3 Bond and G Bond (7th generation). After applying the adhesives, the cavities were filled with Z250 composite resin. The occlusal and gingival microleakage was evaluated using 2% basic fuchsin staining technique. Data were analyzed using Kruskal-Wallis and Bonferroni corrected Mann-Whitney U tests. Results: The mean rank of occlusal microleakage exhibited significant differences by comparison of G Bond, Clearfil S3 Bond and Single Bond2 (21.07, 30.67) and 17.27, respectively) (P=0.005). There was a significant difference in gingival microleakage of different bonding agents (34.40, 17.83 and 16.77 for G Bond, Clearfil S3 Bond and Single Bond2, respectively) (P<0.001). There was a significant difference in occlusal microleakage of Clearfil S3 Bond and Single Bond2 (P= 0.003), but no significant difference was found between Clearfil S3 Bond and G Bond (P=0.025). No significant difference was observed between occlusal microleakage by G Bond and Single Bond2 (P=0.238). The difference in gingival microleakage was significant by G Bond compare with Single Bond2 and Clearfil S3 Bond (P<0.001and P<0.001, respectively). Conclusion: The microleakage of class V composite restorations in permanent teeth using the Single Bond2 was lower than that with the use of G Bond in gingival margins. The sealing ability with Single Bond2 was superior to Clearfil S3 Bond in occlusal margin but they were equally effective at gingival margin.

Evaluation of the efficacy of flowable composite as lining material on microleakage of composite resin restorations: A systematic review and meta-analysis.

The efficacy of flowable composite in improving marginal adaptation or reducing microleakage is not fully understood. The purpose of this study was to systematically evaluate existing evidence to verify whether an application of flowable composite as a liner provided less microleakage in Class 2 composite restorations. PubMed, ISI (Web of Science), and Scopus databases were searched according to the selected keywords, up to 15 Feb 2015, without any restriction on date or language. Full texts of published articles that seemed to meet primary criteria for inclusion in this research were obtained. Data of studies were extracted if they were assessed as high or moderate level of evidence. Due to the variation of methods used in different studies, they were divided into five groups: groups 1 and 2, studies that evaluated the effect of flowable composite as a liner on dentinal or enamel margins and applied flowable composite on all of the cavity wall margins; groups 3 and 4, studies that evaluated the effect of flowable composite as a liner on dentinal and enamel margins and applied flowable composite only on gingival margin; and group 5, clinical studies. The initial search yielded 1,370 publications. After hand searching, six extra studies were included in the review. The abstracts of all were read independently by AB and SG. After methodologic assessment and evaluation of the level of evidence, 18 studies were selected for this study. The results of this study indicate that flowable composite liners have no significant effect on microleakage of composite restorations in all of five groups. Application of flowable composite as a liner in composite restorations cannot reduce microleakage or improve clinical performance.

Evaluation of the Surface Roughness and Microleakage of Dental Composites Exposed to Different Beverages.

The purpose of this study was to determine the effect of different solutions cola soft drink (CSD) and coffee on roughness and microleakage of composite resin restorations. Sixty bovine incisors were prepared and restored using Filtek Z350 XT (3M/ESPE) nanoparticulate resin. The samples were divided into three groups (n = 20): A (control)-Immersion in artificial saliva (14 days); B: Immersion in coffee (14 days), for 15 minutes (3x/day) and C: Immersion in CSD for 14 days (3x/day). Then the samples were analyzed for microleakage (dye penetration) and surface roughness (atomic force microscope). The one-way analysis of variance (ANOVA) was applied to assess the surface roughness and microleakage. The Tukey's test was set at 0.05. Group A (roughness-GAR) presented significantly the lowest average surface roughness. Group C (microleakage-GCM) showed significantly the highest average microleakage. It was concluded that CSD and coffee change the surface roughness and increase the microleakage of restorations. Nowadays there is a high consumption of artificially sweetened soft drinks, sports drinks, high-energy beverages and coffee products by people that cause problems in composite resin restorations.

Marginal Seal of Water-Based Formulation of Light Activated Bonding Agent for Use in Combination with Adhesive Restorations

Aim: The purpose of the study was to investigate effect of water-based solvent adhesive system on micro-leakage of composite resinrestorations. Materials and methods: Class V cavities were prepared on buccal and lingual surfaces of 20 human molars, The occlusal margins were prepared in enamel while cervical ones were prepared in dentin below CEJ by one mm, and classified into four groups according to type of adhesive used five teeth each: Adper Single Bond2 was used as control, Clearfil SE Bond water-based adhesive, Clearfil S3 Bond ethanol-based adhesive, I-Bond acetone-based adhesive. All cavities were restored with Filtek Z250 composite, stored in distilled water at 37?C for 24 hours and thermal cycled. All surfaces, except for restorations and 1 mm from the margins, were coated with two layers of nail varnish. The teeth were immersed in a 3% methylene blue dye solution for 24 hours, and then rinsed in running water, blot-dried and sectioned longitudinally through center of restorations from the facial to lingual surface. The sections (10 sections for each group by n=20 readings) were blindly assessed for microleakage of dye penetration for both the occlusal and gingival margins. Data were collected and statistically analyzed. Results: Results demonstrate a comparable significantly lesser mean dye penetration in Adper single Bond2 adhesive than in other groups at enamelmargins (p<0.05) and a highly significant lesser mean dye penetration at dentin margins. Clearfil SE Bond water-based adhesive showed a significant higher mean value of dye penetration at dentin margins than either ethanol or acetone-based adhesives and a comparable non significantly lesser mean dye penetration score at enamel margins. Conclusion: Clearfil SE Bond (water-based adhesive) showed a significant higher mean value of dye penetration score at dentin margins than either ethanol or acetone-based adhesives.

Marginal microleakage of composite resin restorations bonded by desensitizing one step self etch adhesive

AimThe aim of this study was to investigate the effect of desensitizing agents on microleakage of composite resin restorations bonded by one step desensitized self etch adhesive. Materials and methodsClass V cavities (3 × 4 × 2 mm) were prepared on the buccal surfaces of 30 human molars, Teeth were classified into three groups according to the type of adhesive used (n = 10). Group 1: Adper Single Bond2. Group 2: l-bond. Group 3: is a control group of composite resin restoration without bonding agent. All cavities were restored with Filtek Z250 composite resin, stored in distilled water at 37 °C for 24 h and thermal cycled for 500 cycles. The root apices were sealed with utility wax, and all the surfaces, except for the restorations and 1 mm from the margins, were coated with two layers of nail varnish. The teeth were immersed in a 3% methylene blue dye solution for 24 h, and then rinsed in running water, blot-dried and sectioned longitudinally through the center of restorations from the facial to lingual surface. The sections were blindly assessed for microleakage of dye penetration by two independent evaluators using a stereomicroscope at 30× magnification for both the occlusal and gingival margins. Data were collected and statistically analyzed. ResultsA Mann–Whitney test demonstrated the highest significantly dye penetration rate for group 3 versus tested groups comparing the occlusal and gingival scores for each group, Wilcoxon Rank test showed significant difference for all groups. Etch and rinse adper single bond2 adhesive record a lower significant scores of dye penetration than self etch adhesive I-bond at both enamel and dentin margins. ConclusionAll adhesive systems exhibited dye penetration at both occlusal and gingival margins. Etch and rinse system is still considered a gold standard adhesive. Adper single bond2 revealed significantly less leakage compared to I-Bond.

Effects of antioxidants on the microleakage of composite resin restorations after external tooth bleaching.

Objective:To compare the effects of three antioxidants (sodium ascorbate, sodium ascorbate combined with a surfactant, and catalase) on the microleakage of composite resin restorations after external tooth bleaching with 10% carbamide peroxide.Materials and Methods:Buccal cavities were prepared on the surface of 60 intact premolars, which were randomly divided into six groups. All cavities were filled with composite resin. In group 1, teeth were not bleached; in group 2, cavities were filled immediately after bleaching; in group 3, cavities were delay-filled for 3 weeks; in group 4, cavities were treated with sodium ascorbate after bleaching and then filled; in group 5, cavities were treated with sodium ascorbate combined with surfactant after bleaching and then filled; and in group 6, cavities were treated with catalase after bleaching and then filled. Microleakage of the restorations was measured from sections using a stereomicroscope.Results:Group 1 displayed the least amount of microleakage, while group 2 showed the greatest amount of microleakage (P < 0.05). Groups 3 and 4 were similar to group 2 (P > 0.05). However, groups 5 and 6 showed a significantly lower amount of microleakage compared to group 2 (P < 0.05).Conclusion:Microleakage increased significantly after external bleaching with 10% carbamide peroxide, and decreased when the bleached teeth were treated with sodium ascorbate combined with Tween® 80, or with catalase. Catalase was more effective in decreasing microleakage, while delayed filling or treatment with sodium ascorbate alone did not effectively decrease the microleakage.

Sealing ability of a new calcium silicate based material as a dentin substitute in class II sandwich restorations: Anin vitrostudy

Background: Class ll sandwich restorations are routinely performed where conventional Glass ionomer cement (GIC) or Resin-modified GIC (RMGIC) is used as a base or dentin substitute and a light curing composite resin restorative material is used as an enamel substitute. Various authors have evaluated the microleakage of composite resin restorations where glass ionomer cement has been used as a base in class II sandwich restorations, but a literature survey reveals limited studies on the microleakage analysis of similar restorations with biodentine as a dentin substitute, as an alternative to glass ionomer cement. The aim of this study is: To evaluate the marginal sealing efficacy of a new calcium-silicate-based material (Biodentine) as a dentin substitute, at the cervical margins, in posterior class II sandwich restorations. To compare and evaluate the microleakage at the biodentine/composite interface with the microleakage at the resin-modified GIC/composite interface, in posterior class II open sandwich restorations. To compare the efficacy between a water-based etch and rinse adhesive (Scotch bond multipurpose) and an acetone-based etch and rinse adhesive (Prime and bond NT), when bonding biodentine to the composite. To evaluate the enamel, dentin, and interfacial microleakage at the composite and biodentine/RMGIC interfaces. Materials and Methods: Fifty class II cavities were prepared on the mesial and distal surfaces of 25 extracted human maxillary third molars, which were randomly divided into five groups of ten cavities each: (G1) Biodentine group, (G2) Fuji II LC GIC group, (G3) Biodentine as a base + prime and bond NT + Tetric N-Ceram composite, (G4) Biodentine + scotchbond multi-purpose + Tetric N-Ceram composite, (G5) Fuji II LC as a base + prime and bond NT+ Tetric-N Ceram composite. The samples were then subjected to thermocycling, 2500× (5°C to 55°C), followed by the dye penetration test. Scores are given from 0 to 3 based on the depth of penetration of the dye at the cervical, dentin, and interfacial surfaces. The data was analyzed with the nonparametric Kruskal-Wallis and Mann Whitney U test. Results: No statistically significant differences were found between the five groups in the enamel, dentin, and interfacial regions. Conclusion: Within the limits of this in vitro study, biodentine is a new calcium-silicate-based material, which can be used as a dentin substitute in class II open-sandwich restorations, where its scores better than resin-modified GIC.

Microleakage effect on class V composite restorations with two adhesive systems using different bleaching methods

Objective. The main objective of this study was to evaluate the effects of an at-home and two in-office (chemically activated and KTP laser-activated) bleaching methods on the microleakage of composite resin restorations bonded with etch-and-rinse and self-etch adhesive systems. Materials and methods. Class V cavity preparations were performed on 96 premolars and teeth were divided into two groups according to the two adhesive systems (etch-and-rinse and self-etch). After cavities were restored with an adhesive systems and composite resin, they were submitted to thermocycling procedures. Teeth were divided into four sub-groups according to the bleaching systems (control, at-home bleaching, chemically activated office bleaching and KTP laser-activated office bleaching). After the bleaching procedure, teeth were evaluated for marginal leakage. All data were analyzed using the Mann-Whitney U and Kruskal-Wallis tests (p < 0.05). Results. The results of the present study showed that the control group presented lower microleakage values compared with the groups treated with bleaching agents, except for the chemically activated in-office bleaching. When the scores of microleakage at the enamel and gingival margins of the four groups were compared, the differences among the groups were found to be statistically significant (p < 0.05). Comparing the gingival and enamel margins in each group, statistically significant differences were found in the at-home group (p < 0.05) and no significant differences were seen in the other groups (p > 0.05). No significant difference was found between the adhesive systems after treatment with the same bleaching techniques. Conclusion. Under the conditions of this study, microleakage of composite resin restorations differs according to the bleaching methods used and no difference was found between the adhesive systems.

Comparison of the Effect of Nd:YAG and Diode Lasers and Photodynamic Therapy on Microleakage of Class V Composite Resin Restorations.

Background and aims Considering the importance of disinfecting dentin after cavity preparation and the possible effect of disinfection methods on induction of various reactions between the tooth structure and the adhesive restorative material, the aim of the present study was to evaluate microleakage of composite resin restorations after disinfecting the prepared dentin surface with Nd:YAG and Diode lasers and photodynamic therapy. Materials and methodsStandard Class V cavities were prepared on buccal surfaces of 96 sound bovine teeth. The samples were randomly divided into 4 groups based on the disinfection method: Group 1: Nd:YAG laser; Group 2: Diode laser; Group 3: photodynamic therapy; and Group 4: the control. Self-etch bonding agent (Clearfil SE Bond) was applied and all the cavities were restored with composite resin (Z100). After thermocycling and immersing in 0.5% basic fuchsin, the samples were prepared for microleakage evaluation under a stereomicroscope. Data was analyzed with Kruskal-Wallis and Wilcoxon signed-rank tests at P<0.05. ResultsThere were no significant differences in the microleakage of occlusal and gingival margins between the study groups (P>0.05). There were no significant differences in microleakage between the occlusal and gingival margins in the Nd:YAG laser group (P>0.05). In the other groups, microleakage at gingival margins was significantly higher than that at the occlusal margins (P<0.05). ConclusionNd:YAG and Diode lasers and photodynamic therapy can be used to disinfect cavity preparations before composite resin restorations.

Effect of Three Different Mouthrinses on Microleakage of Composite Resin Restorations with Two Adhesive Systems after Bleaching with 10% Carbamide Peroxide

The aim was to evaluate the effects of Oral-B (OB), Listerine (LN) and Rembrandt Plus (RM) mouthrinses on microleakage of composite resin restorations bonded with two adhesive systems after bleaching with 10% carbamide peroxide. A total of 60 Cl V cavities were prepared on human premolars. The occlusal and gingival margins were placed 1 mm occlusal to and apical to CEJ respectively. The teeth were randomly divided into two groups based on the adhesive system used: Excite (EX) and Clearfil SE Bond (CSE) groups. After composite resin restoration of cavities, thermocycling and bleaching with 10% carbamide peroxide for 2 hours daily for 14 days, the teeth in each adhesive group were further subdivided into three subgroups and were immersed for 12 hours in the three OB, RM and LN mouthrinses. The teeth were then placed in 2% basic fuschin for 24 hours. After dissecting the teeth, microleakage was evaluated under a stereomicroscope at 16×. Data was analyzed with multifactor ANOVA and Bonferroni test at p < 0.05. Microleakage with EX was significantly higher than that with CSE (p = 0.009). Microleakage at gingival margins was significantly higher than that at occlusal margins (p = 0.15). Microleakage with OB was higher than that with LN (p = 0.02). However, there were no significant differences in microleakage between LN and RM (p = 1) and between RM and OB (p = 0.15). In addition, with the EX adhesive system, microleakage with OB was higher than that with LN and RM (p = 0.02). In the present study, microleakage of composite resin restorations was influenced by the type of the adhesive system, mouthrinse type and the location of the cavity margin. Use of some mouthrinses, such as OB after bleaching can increase postrestoration microleakage of resin composite restorations bonded with etch-and-rinse adhesive systems.