Amount Of Microleakage Research Articles

Comparative Assessment of Marginal Micro Leakage of Different Esthetic Restorative Materials Used on Primary Teeth: An In-vitro Study.

The aim of the current investigation was to evaluate the marginal microleakage of various esthetic restorative materials applied to primary teeth. A total of 75 noncarious primary molars that were removed for orthodontic intervention and teeth nearing exfoliation were chosen. One millimeter (mm) above the cementoenamel junction, on the buccal surface of the teeth, Class V cavities were prepared. William's graded periodontal probe was used to standardize cavity preparation on all teeth. 3 mm was the cavity's length, 2 mm in width, and 2 mm in depth. The teeth were then divided into three groups (25 samples in each group) according to the type of esthetic restorative material used. Group I: Resin-modified glass ionomer cement, Group II: Ormocer, Group III: Giomer. The samples underwent 500 cycles of thermocycling, with an immersion time of 60 seconds and a well time of 15 seconds, between 5 and 55°C. The samples were submerged in methylene blue dye for 24 hours at room temperature and dried. The samples were then divided into sections and examined with a stereomicroscope. Data was recorded and statistically analyzed. The least marginal microleakage was found in the ormocer group (1.22 ± 0.01) followed by resin-modified glass ionomer cement group (1.31 ± 0.07) and the giomer group (1.78 ± 0.03). There was a highly statistically significant difference found between resin-modified glass ionomer cement group and the ormocer group, resin-modified glass ionomer cement group and giomer group. And no significant difference was found between the ormocer group and the giomer group. The present study concluded that there was some amount of microleakage in primary teeth in all restorative materials examined in this in-vitro investigation. However, the marginal sealing ability of ormocer was found highest compared to resin-modified glass ionomer cement and Giomer materials. The primary reason dental restorations fail, particularly in Class V cavities, is microleakage since the margins of these restorations are typically found in the dentin or cementum. Assessing microleakage is a crucial step in determining the marginal integrity of restorative materials. Developing methods and resources that reduce the adverse effects caused by the restorative marginal seal failing would benefit from this. How to cite this article: Al Ghwainem A, Alqarni AS. Comparative Assessment of Marginal Micro Leakage of Different Esthetic Restorative Materials Used on Primary Teeth: An In-vitro Study. J Contemp Dent Pract 2024;25(1):58-61.

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.

Evaluation of Microleakage of Stainless Steel Crowns and Pedo Jacket Crowns after Cementation With Different Luting Cements.

The present research was conducted to assess the microleakage of stainless steel crowns along with pedo jacket crowns following cementation with different luting cements. A total of 60 deciduous teeth subjected to extraction were employed in this in vitro research. These 60 specimens were randomly divided into two groups: Group I: Stainless steel crowns and Group II: Pedo Jacket crowns. Both crowns were subjected to cementation using self-cure resin-modified glass ionomer (RMGI) cement as well as by means of self-adhesive universal resin cement (RelyX luting cement). The specimens were subjected to storage in distilled water at 37°C for 24 h and were subjected to 500 thermal cycles between 5°C and 55°C using a dwell span of 30 s. Individual surfaces were assessed for the amount of dye infiltration at the boundaries by the side of the tooth-cement border beneath a stereomicroscope under 50× magnifying power. At the mesial and distal surfaces, the amount of microleakage was measured in micrometers (μm), and the mean value was computed for each sample. Stainless steel crowns subject to cementation with RelyX luting cement exhibited the lowest microleakage (0.88 ± 0.78) versus self-cure RMGI cement (0.94 ± 0.78). There was no statistically significant difference found between the groups. Pedo Jacket crowns subject to cementation with RelyX luting cement exhibited the lowest microleakage (0.96. ± 0.32) while self-cure RMGI cement (1.83 ± 0.16) depicted the maximum microleakage. There was an extremely statistically noteworthy dissimilarity noted among the groups. The current research concluded that Pedo Jacket crowns subjected to cementation with RelyX luting cement can be regarded as an esthetically pleasing restorative alternative for numerous young patients. Applying RelyX luting cement to Pedo Jacket crowns provides a strong bolstering by composite materials that ensures the success of the therapy provided.

Evaluation of Sealing Ability of MTA Flow, Biodentine and Pro-Root MTA to Seal the Furcal Perforation with and without Internal Matrix- An In vitro Study.

Endodontic mistakes, also known as procedural accidents, are those bad events that occur during treatment, some of which are attributable to a lack of attention to detail and others of which are completely unforeseeable. The second most frequent reason for root canal failure is perforation. The current in vitro study's objective was to assess the furcal perforation's potential to be sealed with and without internal matrix by MTA flow, Biodentine, and pro-root MTA. 60 samples were allocated into six groups at random (10 each). In intact permanent mandibular first and second teeth, furcal perforation sites were made and sealed with various materials. Following perforation sealing, the specimens' capacity for sealing was evaluated using the dye penetration method. The current study's findings indicated that Group 2 has the least amount of microleakage and Group 5 has the most. Biodentine has excellent sealing capabilities and can be utilised to heal furcation perforations with or without internal matrix.

Comparison of Retention and Marginal Discoloration of Self-Etch and Total-Etch Adhesives before Pit and Fissure Sealant Application on Permanent Second Molars in Pediatric Patients. A 1-year follow-up longitudinal study

Objective: To compare the retention and marginal discoloration of Self-etch and Total Etch Adhesive during Pit and Fissure Sealant application at 1 month, 3 months, 6 months, and 12 months. Materials and methods: 30 school-going children received sealants in all four permanent second molars, carried out in the Department of Pedodontics and Preventive Dentistry. The fully erupted second permanent molars were randomly allocated into 3 groups: group A (self-etch), B (Total etch), and C (control group). According to the split mouth design, each patient received sealant in the second molar with self-etch in one arch and total-etch in the other arch; contra-lateral molars were kept in the control group. Results: No statistically significant difference was found in the marginal discoloration and microleakage of fissure sealants placed on occlusal surfaces following use of an SE bonding agent and traditional TE adhesive after 12 months. Conclusion: When TE adhesive was put on before sealant, the same amount of microleakage or marginal discoloration happened in the occlusal fissure of permanent teeth as when SE adhesive was put on before sealant.

Riboflavin (Vitamin B2), Turmeric (Curcumin) Photosensitizers Mediated Photodynamic Therapy, and Er, Cr: YSGG on Microleakage of Class V Cavities Restored by Resin-Modified Glass-Ionomer Cement

Purpose: The present study aimed to assess the effect of RF and CP intervened PDT and Er, Cr: YSGG laser on microleakage in class V RMGIC restorations in permanent teeth. Materials and Methods: In-vitro eighty standardized class V cavities (4×4×2) were prepared in extracted permanent molars based on ICDAS II (International Caries Detection and Assessment System II) caries severity code 0. All samples were arbitrarily alienated into four groups: Group 1, PDT mediated riboflavin photosensitizer (RF) [concentration of 150 μg/mL]; Group 2, PDT with curcumin photosensitizer (CP) [concentration of 100 μg/mL]; Group 3, Er, Cr: YSGG laser application; Group 4, control group: rinsed and dried dentin. Cavities were restored with conventional RMGIC. The specimens were immersed in 0.5% Fuchsine solution for 24 hrs. and sectioned. Microleakage scores were assessed under a microscope. Intergroup and intragroup comparisons were made at enamel and cementum margin respectively. Data were analyzed by non-parametric Kruskal-Wallis test and Wilcoxon tests at the level of significance deemed p &lt; 0.05. Results: Riboflavin and curcuminmediated PDT would produce a superior reduction (95% viz 90%) of microleakage as compared to Er, Cr: YSGG laser (85%), and no control groups. Cu-PDT observed the highest amount of microleakage with the least amount of microleakage in the control group. Conclusion: Riboflavin and curcumin photosensitizers mediated PDT and Er, Cr: YSGG laser has the potential to be utilized in class V cavities before RMGIC restorations at enamel margins without adversely affecting the marginal integrity.

Antioxidants Reduce Microleakage of Resin-based Composite Fillings and the Associated Toxicity After Bleaching Human Teeth

Background: Bleaching teeth is popular because the discoloration is a major people’s concern. This study aimed to compare the effect of three antioxidants on the microleakage of composite resin filling after bleaching teeth with 35% H2O2, thus minimizing the potential clinical toxicity of filling materials entering patients’ body. Methods: Sixty-six extracted intact teeth were included in this study. After preparation of a ClV cavity on the buccal surface, the teeth were randomly divided into six groups (n=11, each). Except for group A (control), all others were bleached. Cavities in group A were filled with composite resin. In group B, the samples were immediately restored after bleaching while in group C, the filling was delayed for two weeks after bleaching. In groups D, E, and F, the cavities were treated with either sodium ascorbate, ascorbic acid, or vitamin C, and the filling restored. Teeth were sectioned and the microleakages examined microscopically, and the data were analyzed statistically. Results: Group A showed the least amount of microleakage. In Group B, there was a significant increase in the microleakage when the samples were filled immediately after bleaching. The microleakages among groups of C, D, E, and F were similar to those in group A. Conclusion: The microleakage increased significantly after bleaching with 35% H2O2, while treating dental cavities with the antioxidants effectively reduced the microleakage. Thus, delayed filling is a useful approach to minimize the microleakage. The findings help reduce or prevent the clinical toxicity arising from the microleakage of filling materials.

Confocal laser scanning microscopic evaluation of sealing ability of bone cement, mineral trioxide aggregate and biodentine as root-end filling materials

Aim: To compare the sealing ability of polymethylmethacrylate (PMMA) bone cement, mineral trioxide aggregate (MTA), and Biodentine as root-end filling materials by assessing the degree of microleakage through confocal laser scanning microscopy. Materials and Methods: Thirty extracted maxillary incisors were root canal treated using the rotary ProTaper system. Apical root resections followed by retrograde cavity preparation were done. The teeth were divided into three groups and filled with the 3 tested materials (PMMA bone cement, MTA, and Biodentine). Samples were coated with nail varnish, immersed in 0.5% aqueous solution of rhodamine B dye for 24 h, and rinsed with water to remove excess dye. Samples were horizontally sectioned at 1 mm intervals into three using a diamond disk and were labeled A, B, and C and considered first, second, and third, respectively, based on their distance from the apex. Each slice was divided into four equal parts and evaluated using a confocal laser scanning microscope. Dye penetration was scored based on the amount of microleakage. The data were analyzed using one-way analysis of variance. Results: Intergroup comparison of the mean scores of dye penetration among the three materials showed that there is a statistical difference between PMMA bone cement, MTA, and Biodentine, in sections B and C (P ≤ 0.05). The three groups showed no statistical difference in dye penetration scores in section A. Conclusion: The microleakage is least with PMMA bone cement followed by Biodentine and MTA. Microleakage was least in section C followed by sections B and A.

Microleakage of bulk fill polymer-based composite: review of the literature

Currently, the most widely used dental restoration materials in the field of dental aesthetics are polymer-based composite; therefore, the offer within the market is increasing with a focus on aesthetic, mechanical, and process improvement needs. Bulk fill or block filling polymer-based composite has been widely accepted, they have an advantage because they can be placed in blocks of up to 4 to 5 mm1 reducing clinical times in contrast to traditional polymer-based composite. Therefore, within the present study, we have focused on investigating the microleakage of this type of polymer-based composite and what are the main reasons for it. Objectives: A literature review on the evaluation of the degree of microleakage of bulk fills polymer-based composites. Methodology: An electronic literature search was performed on bibliographic bases such as PubMed, Scielo, Science Direct, Cochrane, and Wiley Online using the keywords: “marginal adaptation”, “bulk fill resin”, “bulk fill composite”, and “microleakage”. Conclusions: Block filling polymer-based composite tends to have the same amount of microleakage as conventional polymer-based composite. Adhesive systems are essential to greatly reduce the formation of gaps between dental materials and dental structures. Class II cavities will always be better to treat the proximal face first and then manage as a class I to reduce marginal microleakage. The fluid block filling polymer-based composite used as a base greatly helps the adaptation of the polymer-based composite and decreases marginal microleakage.

Comparative Evaluation of Microleakage of Two Step Etch and Rinse, Two Step Self Etch and Universal Dentin Bonding

Introduction: Dental composites have been extended as the selected material in most of recent restorations. However, the contraction caused by their polymerization remains the main issue. The stress made by this contraction could cause the divide of composite-tooth junction to be severed. Bacteria, liquids, molecules or ions could cross the gap made between the repair and the cavity wall which this process is called micro-leakage. Micro-leakage causes leakage, tenderness, secondary decay, damage to the pulp, marginal discoloration, which finally results in restoration failure. It can be said that the success of resin restoration material depends perfectly on the ability of the enamel and dentin bonds. This research aims to determine the best bonding to decline micro-leakage. Materials and Methods: In this research, 48 human premolar teeth were prepared without decay, restoration, fracture and wear. Each class V standard cavity was prepared on buccal and lingual surfaces. The shaved teeth were randomly divided into 4 groups including 12 ones. They were polished after restoration. All samples of the 4 groups were subjected to the heat cycling. Apex was sealed with adhesive wax and all parts of the tooth were covered with two layers of nail polish. The samples were incubated in 0.5% Fuchsin solution for 24 hours at room temperature. After that, they were washed under the faucet and the nail polish was removed from tooth surface. Teeth were divided into two mesio distal sections by a cutting machine. Samples were observed by stereo microscope. samples were evaluated based on the micro-leakage grading. Kruskal-Wallis, Mann-Whitney and Will Coxson tests were used to evaluate the results. Results: In each group, 48 cavities were examined. The results of this research showed that in none of enamel surface of bindings, micro-leakage was observed. In the dentine area, the least amount of micro-leakage was related to the Clearfil SE Bond. There was no statistically significant difference between the micro-leakage of Clearfil SE Bond and G Premio Bond by Self Etch method (P value&gt; 0.05). Also, there was no significant difference between micro-leakage of G_Premio Bond by Self Etch and G_Premio Bond by Etch and Rinse method. The micro-leakage of Adper Single Bond 2 was significantly higher in the dentin rather than the other groups. Conclusions: In dentine level, the highest micro-leakage was related to Adper Single Bond 2 bonding and the least one was in Clearfil SE Bond and G Premio Bond by Self Etch method.

Evaluation of the marginal microleakage of CAD-CAM compared with conventional interim crowns luted with different types of cement: An in-vitro study.

Temporary stage in crowns and bridgework plays an important role in the success and failure of the final restorations. Lack of marginal seal of the temporary restorations can lead to further complications. Recently, digital dentistry has been improved in terms of marginal integrity. The aim of this study was to evaluate and compare the marginal leakage between CAD/CAM and conventionally made Polymethyl methacrylate (PMMA) interim crowns cemented with different temporary luting cements. Sixty resin dies of a maxillary right first premolar were prepared according to the protocol of the tooth preparation for all-ceramic crown. Interim crowns were then fabricated and assigned to two main groups according to the fabrication technique (CAD/CAM technique and conventional technique). Furthermore, the samples were sub-grouped (n = 10) according to the type of the luting cements: Zinc oxide eugenol (RelyX temp E), Zinc oxide non-eugenol (RelyX temp NE), and Zinc polycarboxylate cement (pentron). The specimens were then subjected to thermocycling at 5°C and 55°CC for 30 sec and transfer time of 15 seconds for 1500 cycles. After that, the specimens were immersed in a 2% methylene blue solution for 24 hours. The cemented specimens were sectioned buccolingually and the amount of marginal leakage was evaluated under digital microscope at magnification 50x. The scores of dye penetration were recorded and analyzed using one-way ANOVA at P < 0.05 for all tests. For the fabrication technique, CAD/CAM-made interim crowns had significantly better performance in terms of lower microleakage in comparison to conventionally built interim crowns (P < 0.001). Overall, Zinc Oxide non-eugenol also showed significantly least microleakage as a luting cement then Zinc Oxide Eugenol and the most microleakage was found with Zinc Polycarboxylate regardless of the fabrication method. Interim crowns fabricated by CAD-CAM system are better suited for temporization. Zinc-oxide non-eugenol cements showed the least amount of microleakage in both types of crown.

Efficacy of antibacterial sealant to prevent microlekage at the implant superstructure interface – An in vivo study

Objective: The aim of this study is to evaluate the efficacy of antibacterial sealants to prevent microleakage at the implant superstructure interface. Materials and Methods: Around twenty patients were selected after a thorough investigation with lower missing teeth (1st and 2nd premolars 1st and 2nd molars) by inclusion criteria. The patients were divided into two groups Group A (10 patients)– Control group and Group B (10 patients)-test group. The implants were placed with proper surgical protocol in all the patients except that in the test group antibacterial sealant was used before putting the coverscrew. The implants were allowed to osseointegrate for 3 months after which swabs were collected from the interior of the implant once the cover screw was removed. The swabs collected from all the patients were immediately transported to the microbiology laboratory by placing in 1 ml of phosphate buffered saline. The swabs were inoculated on brain heart infusion and McKonkeys medium and processed for routine culture and sensitivity. The identification of the isolates was done by standard microbiological methods. The data thus obtained were subjected to statistical analysis using t-tests for equality. Results: Microbial growth was found in both the groups, but lesser variation in colony-forming units was observed in the test group where antibacterial sealant was used. Conclusions: It was concluded that in spite of using antibacterial sealants; some amount of microleakage was still observed.

Comparative evaluation of microleakage of metallic copings luted with three different commercially available luting cements: An in vitro study.

Aim:To evaluate the microleakage of metallic copings luted with three different commercially available luting cements.Setting and Design:Comparative evaluation in vitro study.Materials and Methods:Thirty replicas of abutment analog were milled and divided into 3 groups. Nickel chromium copings were fabricated; marginal gap was evaluated with optical microscope and luted with Zinc Oxide Non Eugenol cement, Zinc Polycarboxylate cement and Zinc Phosphate cement. After Thermocycling, cemented specimens were placed into 0.5% aqueous solution of basic fuchsin solution for 24 hours for dye penetration. Copings were longitudinally sectioned and microleakage scores were evaluated.Statistical Analysis Used:Kruskal-Wallis analysis of variance (ANOVA) followed by Chi-Square test. Pairwise comparison of groups with Mann Whitney U test.Result:Mean microleakage score was least for Zinc Phosphate cement (1.075 ± 0.85) followed by Zinc Polycarboxylate cement (1.80± 0.23) and most for Zinc Oxide Non Eugenol (2.1± 0.37). The results of the study were statistically significant, P < 0.05.Conclusions:Within the limitations of the study, it was found that all cements exhibited certain amount of microleakage. Zinc Phosphate cement exhibited a mean microleakage score that was significantly lower than Zinc Oxide Non Eugenol cement and Zinc Polycarboxylate cement. When microleakage scores of Zinc Oxide Non Eugenol cement and Zinc Polycarboxylate cement were compared, the difference was found to be insignificant indicating that microleakage in these cements is similar.

Influence of flowable composite liner on the microleakage of posterior packable resin Composites - An in vitro study

Introduction: The aim of this study was to investigate the influence of flowable composite intermediary liner on the microleakage between the tooth tissue and the packable composite resin. Materials and Methods: Forty mandibular molars, each prepared with two class II cavities were randomly divided in two groups: In group A one side was restored with Solitaire (KULZER); the other side was lined with Charisma flow (KULZER) and then restored with Solitaire. In group B one side was restored with Filtek p60 (3M); the other side was lined with Filtek flow (3M) and then restored with Filtek p60. Teeth were then thermocycled for 1000 cycle at 5o and 55o and immersed in a solution of 0.5% basic fuschin dye for 24 hours. Embedded specimens were sectioned longitudinally. Cervical and occlusal microleakage was measured by the extent of dye penetration. Results: Statistically in both groups, microleakge was more in the cavities that were not lined with flowable composites and the cervical margins showed more amount of microleakage as compared to occlusal margins with and without liner. Overall there was no significant difference in the amount of leakage among the two companies at cervical and occlusal margins, with and without flowable liner. Conclusion: Microleakge was more in the cavities that were not lined with flowable composites as compared to cavities lined with flowable composite both in occlusal and cervical margins. The cervical margins showed more amount of microleakage as compared to occlusal margins with and without liner. Keyword: Microleakge, Flowable composite, Packable composite.

THE EFFECT OF THERMOCYCLING ON MARGINAL SEALING ABILITY OF MTA PLUS AND BIODENTINE WHEN USED AS ROOT-END FILLING MATERIALS

Background:Marginal microleakage occurs when restorations are poorly adapted to the cavity walls which leads to penetration of bacteria, fluid and nutrient into the marginal gap. Aim: The study aimed to evaluate the effect of thermocycling on marginal sealing ability of two root-end filling materials i.e. MTA Plus and Biodentine. Materials and Methods: An in vitro study was conducted at Department of Conservative Dentistry and Endodontics in Institute of Dental Sciences (IDS), Jammu, Jammu and Kashmir, India. Forty extracted teeth with single root were decoronated maintaining a standardized length of 16mm. Biomechanical preparation and obturation was done for all the teeth. Samples were stored at 37oC and 100% humidity for seven days. Apical 3mm was resected and cavities were prepared which were randomly divided into two experimental groups with twenty samples each. The cavities were filled with MTA Plus in group I and Biodentine in group II. These groups were further divided into two subgroups of ten each (n=10). The second subgroup of both the groups did not receive any treatment and the first subgroup samples were subjected to 500 thermocycles in water bath at temperature ranges between 5oC and 55oC with a dwell time of 30 second. The samples were immersed in methylene blue dye and after through washing they were sectioned longitudinally. Examination was done under stereomicroscope to measure the depth of penetration. Statistical Analysis: The data collected were put to statistical analysis by one-way ANOVA (analysis of variance) and post hoc tests. Results: The average depth of dye penetration was least for Biodentine when thermocycling treatment was not given (0.13mm) and maximum value was depicted by MTA Plus when undergone thermal cycles (0.57mm). It is also noted that no significant difference is seen in Biodentine with or without artificial aging procedure. Conclusion:Biodentine showed least amount of microleakage, thus a better sealing ability.Alsothere was little effect of thermocycling onmicroleakage of both the materials.

Influence of Cavity Dimensions on Microleakage of Two Bulk-Fill Composite Resins

Objective: To evaluate the effect of cavity dimensions on the amount of microleakage in two different types of bulk-fill composite resins. Material and Methods: Forty class II cavities were prepared in the mesial and distal surfaces of human molars without any carious lesions. The samples were divided into 4 groups (n=10): Group 1: cavities with 3 mm of buccolingual width (known as the smaller cavity), filled with Tetric N-Ceram Bulk Fill composite resin; Group 2: cavities with 6 mm of buccolingual width (larger cavity), filled with Tetric N-Ceram Bulk Fill composite resin; Group 3: cavities with 3 mm of buccolingual width, filled with X-Tra Base composite resin; and Group 4: cavities with 6 mm of buccolingual width, filled with X-Tra Base composite. After the specimens were thermocycled for 500 cycles at 5/55°C, they were immersed in 1% methylene blue for 24 hours, and then cut into sections mesiodistally in the longitudinal axis of each tooth. Then, the samples were scored regarding the amount of dye penetration in two occlusal and gingival areas under a stereomicroscope (x32). Data was submitted to Kruskal-Wallis and Mann-Whitney tests. Results: The highest degrees of microleakage in larger cavities filled with X-Tra Base among the four groups. There was a significant statistic difference (p=0.012) between large and small cavities filled with X-Tra Base (Groups 3 and 4); however, there was no significant difference between the two cavity sizes of Tetric N-Ceram Bulk-filled groups. Conclusion: Microleakage of composite resins depends on the dimension of the cavity and the type of composite resin used.

The influence of implant\u2013abutment connection on the screw loosening and microleakage

BackgroundThere are some spaces between abutment and implant body which can be a reservoir of toxic substance, and they can penetrate into subgingival space from microgap at the implant–abutment interface. This penetration may cause periimplantitis which is known to be one of the most important factors associated with late failure. In the present study, three kinds of abutment connection system, external parallel connection (EP), internal parallel connection (IP), and internal conical connection (CC), were studied from the viewpoint of microleakage from the gap between the implant and the abutment and in connection with the loosening of abutment screw.MethodsWe observed dye leakage from abutment screw hole to outside through microgap under the excessive compressive and tensile load and evaluated the anti-leakage characteristics of these connection systems.ResultsDuring the experiment, one abutment screw for EP and two screws for IP, out of seven samples in each group, were fractured. After the 2000 cycles of compressive tensile loadings, removal torque value (RTV) of abutment screw represented no statistical differences among three groups. Standard deviation was largest in the RTV of EP and smallest in that of CC. The results of microleakage of toluidine blue from implant–abutment connection indicated that microleakage generally increased as loading procedure progressed.The amount of microleakage was almost plateau at 2000 cycles in CC, but still increasing in other two groups. The value of microleakage greatly scattered in EP, but the deviation of that in CC is significantly smaller. At 500 cycles of loading, there were no significant differences in the amount of microleakage among the groups, but at 1000, 1500, and 2000 cycles of loading, the amount of microleakage in CC was significantly smaller than that in IP. Throughout the experiment, the amount of microleakage in EP was largest, but no statistical difference was indicated due to the high standard deviation.ConclusionsWithin the limitation of the present study, CC was stable even after the loading in the RTV of abutment screw and it prevented microleakage from the microgap between the implant body and the abutment, among the three tested connections.

Microleakage around zirconia crown margins after ultrasonic scaling with self-adhesive resin or resin modified glass ionomer cement.

To measure microleakage around zirconia crown margins cemented with self-adhesive resin or resin modified glass ionomer (RMGI) cement after ultrasonic scaling. 16 molars were prepared for crowns (margin 0.5mm coronal of cementum-enamel junction). Preparations were digitally scanned and zirconia crowns milled. Specimens were divided into two groups (n=8): self-adhesive resin (RelyX Unicem 2) or resin modified glass ionomer (RMGI) (RelyX Luting Plus) cements. After cementation, specimens were ultrasonic scaled with a piezoelectric device (60s, hand pressure). After thermocycling (20,000 cycles/5-55°C), specimens were immersed in 5wt% fuchsine dye before sectioning bucco-lingually. Microleakage was examined under 40× light magnification. Statistical comparisons were made using a paired t test and a two-sample t test (α=.05). Ultrasonic scaling did not alter microleakage at the margins of crowns (P=.31). There was no significant difference in microleakage of scaled and untreated margins with the use of different cements (P=.21). The amount of microleakage around margins that were scaled was not significantly different between cements (P=.14). Untreated margins of crowns cemented with RelyX Luting Plus showed a significantly higher microleakage than those cemented with RelyX Unicem 2 (P=.005). Piezoelectric ultrasonic scaling did not increase microleakage at the margin of zirconia crowns cemented with self-adhesive resin or RMGI cements. Piezoelectric ultrasonic scaling around zirconia crowns did not impact marginal microleakage cemented with self-adhesive resin or RMGI cements.

Microleakage at the Different Implant Abutment Interface: A Systematic Review.

Presence of gap at the implant-abutment interface, leads to microleakage and accumulation of bacteria which can affect the success of dental implants. To evaluate the sealing capability of different implant connections against microleakage. In January 2017 an electronic search of literature was performed, in Medline, EBSCO host and Pubmed data base. The search was focused on ability of different implant connections in preventing microleakage. The related titles and abstracts available in English were screened, and the articles that fulfilled the inclusion criteria were selected for full text reading. In this systematic review, literature search initially resulted in 78 articles among which 30 articles only fulfilled the criteria for inclusion and were finally included in the review. Almost all the studies showed that there was some amount of microleakage at abutment implant interface. Microleakage was very less in Morse taper implants in comparison to other implant connections. Majority of studies showed less microleakage in static loading conditions and microleakage increases in dynamic loading conditions. In this systematic review maximum studies showed that there was some amount of microleakage at abutment implant interface. External hexagon implants failed completely to prevent microleakage in both static and dynamic loading conditions of implants. Internal hexagon implants mainly internal conical (Morse taper) implants are very promising in case of static loading and also showed less microleakage in dynamic loading conditions. Torque recommended by manufacturer should be followed strictly to get a better seal at abutment implant interface. Zirconia abutments are more to microleakage than Titanium abutments and there use should be discouraged. Zirconia abutments should be only restricted to cases where there was very high demand of aesthetics.