Showing 48 results for Leakage
Amir Ghasemi, Hasan Torabzadeh, Majid Nasiri, Samaneh Mahvidyzadeh,
Volume 24, Issue 4 (1-2012)
Abstract
Background and Aims: The aim of this study was to evaluate the quality of an experimental hydrofluoric acid (HF) for preparation of porcelain and to compare it with two commercial hydrofluoric acids in Iranian trademark.
Materials and Methods: A- Evaluation of etch pattern of experimental HF using scanning electron microscope (SEM): 6 feldespathic discs were divided into 3 groups. Each group was etched with related HF (experimental, Ultradent and Kimia) for 1 minute. SEM images were recorded at 3 magnifications. B- Bond strength test: 18 feldespathic discs were considered for each acidic group. Then the porcelain surfaces were etched and bonded to composite with unfilled resin. Consequently, the microshear test was done. C- Microleakage test: 54 discs were divided into 3 groups (n=18). Then the porcelain surfaces were etched and bonded to composite with unfilled resin and finally observed under stereomicroscope. The data were analyzed with one-way ANOVA and Smirnov tests.
Results: SEM analysis showed no difference between groups in terms of etch pattern. Microshear bond strength values for experimental, Kimia, and Ultradent HF were 28.53 (±4.92), 28.21 (±6.61), and 26.14 (±7.61) MPa, respectively. There was no significant difference between the bond strength of test groups (P<0.05). Furthermore, no significant difference was found between the microleakage of test groups (P>0.05).
Conclusion: Quality of experimental HF in terms of etch pattern, microshear bond strength and microleakage of composite/porcelain interface was similar to that of two commercial hydrofluoric acids.
Abdolrahim Davari, Alireza Danesh Kazemi, Mosa Aboali,
Volume 25, Issue 1 (4-2012)
Abstract
Background and Aims: When composite resin polymerizes, shrinkage stresses tend to produce gaps at the tooth/ restoration interfaces. Surface sealants may reduce or avoid problems related to the marginal interface. The aim of this study was to evaluate the effect of two different surface sealants (Fortify and Optiguard) on the microleakage of class V resin composite restorations.
Materials and Methods: Twenty three sound noncarious molars were collected. Totally, 45 Class V cavities with the occlusal margins in enamel and cervical margins in cementum were prepared in both buccal and lingual surfaces. The specimens were randomly assigned in three groups (15 cavities in each group) and then restored with a resin composite. After the finishing and polishing procedures, the restorations in each group were covered with a specific surface sealant, except for the control samples, which were not sealed. After placing restorations, the specimens were thermocycled and then immersed in a 50% silver nitrate solution (tracer agent) for four hours, sectioned longitudinally and analyzed for leakage using a stereomicroscope in a blind manner. The marginal microleakage was evaluated at the occlusal and cervical interfaces and compared among the three groups using the Kruskall-Wallis and the Mann-Whitney U tests.
Results: Microleakage was found in all groups at both occlusal and cervical margins. Significantly greater leakage was observed at the cervical margins compared to the enamel margins of the material groups (P=0.005). There was no statistically significant difference among the groups at occlusal margins (P=0.66). In the cervical region, Fortify showed improved results and statistically presented the lowest degree of microleakage (P=0.003).
Conclusion: The used sealant materials presented different rates of effectiveness and Fortify decreased marginal microleakage significantly.
Alireza Heidari, Mehdi Shahrabi, Sara Ghadimi, Shahram Mosharafian, Hosein Ansari, Zohreh Rafiee,
Volume 25, Issue 2 (4-2012)
Abstract
Background and Aims: Using the conservative adhesive resin restoration (CAR) in uncooperative children lead to numerous problems because of being time consuming. The purpose of this study was to compare the microleakage of conservative adhesive resin restoration under separate curing and co-curing.
Materials and Methods: In this experimental study, 120 intact premolar teeth were collected and 120 vertical grooves were prepared on them. Then the teeth were divided into four groups: group 1, separated curing of bonding agent, flowable composite and sealant group 2, co-curing of all materials for 60 seconds group 3,
co-curing of all materials for 40 seconds and group 4, co-curing of all materials for 20 seconds. Then the specimens were thermocycled and immersed in basic fuchsin solution. The teeth were sectioned horizontally and dye penetration was evaluated with stereomicroscope. Date were analyzed using one-way ANOVA and Scheffe test.
Results: Mean value of dye penetration in groups 1, 2, 3, and 4 was 1.53±0.6, 2.06±0.6, 2.5±0.7 and 3.53±0.6, respectively. There was a statistically significant difference between group 1 and the other groups (P=0.0001).
Conclusion: Considering the problems caused by microleakage in conservative resin adhesive restorations, co-curing method should not be used. In the case of using co-curing method, 60 second curing time is suggested for sufficient polymerization.
Azita Kaviani, Fateme Asareh,
Volume 25, Issue 3 (7-2012)
Abstract
Background and Aims: Although composite resin restorations have many advantages, they can lead to several clinical problems. The primary reason for these problems is microleakage. The aim of this study was to compare the rebonding effect on microleakage of class V composite restorations using two low viscosity resins.
Materials and Methods: In this in vitro study, 60 class V composite restorations were performed in buccal and lingual surfaces of human extracted premolars with the occlusal margin in enamel and the gingival margin in dentin/cementum. The teeth were randomly divided into 3 groups: (I) restorations with no rebonding, (II) restoration margins rebonded with an enamel adhesive (Margin Bond), (III) restoration margins rebonded with a specific unfilled resin. The specimens were then thermocycled and immersed in 0.5% fuchsin dye solution. The samples were sectioned longitudinally and observed under a stereomicroscope for assessment of microleakage. The data were analyzed by Kruskal-Wallis, Wilcoxon and Mann-Whitney tests. P<0.05 was considered as the level of significance.
Results: Statistical analysis showed a significant difference in the microleakage of gingival margins (P<0.0001), but not in enamel margins (P=0.148). Microleakage at the gingival margins of group (III) was significantly less than that of group (II). Group (I) showed the highest amount of microleakage.
Conclusion: Rebonding by a low viscosity resin reduces microleakage at the gingival margins of class V composite restorations, but has no significant effect on the occlusal margins.
Behnaz Esmaeili, Ainaz Bazazi, Ali Bijani,
Volume 25, Issue 3 (7-2012)
Abstract
Background and Aims: Packable composites with high viscosity might not adapt properly to internal surfaces and cervical areas. The aim of this study was to assess the microleakage of class II posterior composite restorations performed using different methods.
Materials and Methods: Ninety proximal cavities were prepared in extracted sound premolar teeth, divided into three groups and filled as follows: 1- packable composite (3M filtek P60), 2-Hybrid composite (Z250) + P60 composite and 3- Resin-modified glass ionomer liner + P60 composite. Afterwards, the samples were immersed in 0.5% Foushin solution and sectioned. Gingival microleakage was then graded. Obtained data were analyzed using paired t-test and analysis of variance.
Results: In regard to distal cavities, significant difference was seen between the groups 1 and 3 (P=0.01) as well as groups 2 and 3 (P=0.03). Comparing microleakage of mesial and distal cavities, there was a significant difference in groups 1 (P=0.003) and 2 (P=0.005).
Conclusion: Based on the findings of this study, application of Z250 composite had no effect on reduction of microleakage of class II posterior composite restorations. Vitremer liner decreased microleakage in dento-gingival margins.
Mohamad Saieed Sheykhrezaie, Pegah Saraf, Mohamad Hosein Nekofar, Alireza Mohamadi,
Volume 25, Issue 4 (1-2013)
Abstract
Background and Aims: The purpose of this study was to evaluate the sealing ability of different thicknesses of orthograde MTA plugs in comparison with 5 mm gutta-percha.
Materials and Methods: Fifty extracted single rooted human teeth were collected. After root canal preparation, the samples were randomly divided into 4 experimental (n=10) and two control groups (n=5). In group 1, the apical 5 mm of the canals were obturated using laterally condensed gutta-percha and sealer AH26. Groups 2, 3 and 4 received 2, 3 and 4-mm thick orthograde MTA plug, respectively. Thereafter, the coronal portion of specimens was exposed to the microbial solution containing streptococcus sanguis and the root tips were placed in phenol red lactose broth. The color changes were observed within 60 days. The data were analyzed with Fisher exact test.
Results: The leakage was found in all samples (100%) in group 1 and 72.7%, 30.8% and 50% of the samples in groups 2, 3 and 4, respectively. Significant difference was found between 3 mm thickness of MTA plug and gutta percha and sealer (P=0.02).
Conclusion: According to the findings, it seems that 3 mm thickness of orthograde MTA plug had better sealing ability than the other thicknesses of MTA plug as well as the 5 mm of gutta-percha.
Hamid Kermanshah, Esmaiel Yasini, Razieh Hoseinifar,
Volume 26, Issue 1 (3-2013)
Abstract
Background and Aims: Marginal seal in class V cavity and determination of the best restorative material in reducing microleakage is of great concern in operative dentistry. The aim of this study was to evaluate the effect of load cycling on the microleakage of low shrinkage composites compared with methacrylate-based composites with low shirinkage rate in class V cavity preparation. Marginal integrity of these materials was assessed using scanning electron microscope (SEM).
Materials and Methods: In this in vitro study, class V cavity preparations were made on the buccal and lingual surfaces of 48 human premolars and molars (96 cavities). The specimens were divided into four groups each containing 12 teeth (24 cavities): group 1 (Kalore-GC+ G-Bond) , group 2 (Futurabond NR+Grandio), group 3 (All Bond SE+ Aelite LS Posterior), group 4 (LS System Adhesive Primer & Bond+Filtek P90). All the specimens were thermocycled for 2000 cycles (5-50oC). In each group, half of the specimens (n=12) were subjected to 200,000 cycles of loading at 80 N. Epoxy resin replicas of 32 specimens (4 restorations in each subgroup) were evaluated using SEM and the interfacial gaps were measured. Finally, the teeth were immersed in 0.5% basic fuchsin dye for 24 hours at 370C, then sectioned and observed under stereomicroscope. The data were analyzed using Kruskal-Wallis and Mann-Whitney U tests and the comparison between occlusal and gingival microleakage was made with Wilcoxon test.
Results: Within unloaded or loaded specimens, there were no significant differences in microleakage among four groups on the occlusal margins (P>0.05). But there were statistically significant differences in microleakage between silorane and Aelite on the gingival margins (P<0.05). No statistically significant differences were found between the microleakage of the loaded and unloaded groups on both occlusal and gingival margins for all materials (P>0.05).
Conclusion: Silorane did not perform better than the conventional low shrinkage methacrylate-based composite in terms of sealing ability (except Aelite). Cyclic loading did not increase the extent of leakage in any groups.
Baharan Ranjbar Omidi, Ladan Madani, Aida Mirnejad Joybari, Ensyeh Rashvand, Sonia Oveisi,
Volume 28, Issue 2 (7-2015)
Abstract
Background and Aims: Microleakage is an important problem with direct restorations and familiarity with contributing factors is of utmost importance. The aim of this study was to evaluate the microleakage of three glass ionomer restorations in class V cavities.
Materials and Methods: In this in vitro study, class V cavity preparations were made on the buccal and lingual/ palatal surfaces of 30 human premolars (60 cavities). The specimens were divided into three group (n=10, 20 cavities). Restored as follows: group1: with Fuji IX (HVGI) ionomer/G coat plus, group 2: Ionofil molar (HVGI)/ G coat plus, and group 3: Fuji II LC (RMGI) / G coat plus. All specimens were finished and polished immediately and were thermocycled (2000 cycles, 5-50°C) . In each group half of the teeth were load cycled (50000 cycles). Finally, the teeth were immersed in 0.15% basic fushine dye for 24 hours at room temperature and then sectioned and observed under stereomicroscope. Data were analyzed using Kruskal-Wallis, Man- Whitney test and a comparison between incisal and gingival microleakage was made using Wilcoxon analysis.
Results: It was shown that the mechanical load cycling and filling material did not cause a statistically significant increase in the incisal and gingival microleakage in any of groups (P>0.05).
Conclusion: It was concluded that the extent microleakage of Fuji II LC was similar to that of the highly viscous glass ionomers (Ionofil molar, Fuji IX) and load cycling did not increase the microleakage.
Fatemeh Mokhtari, Marzyeh Mirzaei,
Volume 28, Issue 3 (10-2015)
Abstract
Background and Aims: Inadequate root canal obstruction has been suggested as major factor in endodontic treatment failure. On the other hand, the most common way to assess leakage is dye penetration method. In assessing the possible effect of cutting direction on the leakage, the present study was performed to investigate dye penetration in two root cutting directions.
Materials and Methods: Forty human teeth with a single root canal were used in this experimental study. Endodontic treatment was performed on the specimens and then stained with 2% methylene blue solution. The specimens were divided into two groups. Specimens in the first group were sectioned in the buccolingual dimension and the second group in the mesiodistal to evaluate the microleakage. The amount of dye penetration was measured under the stereomicroscope with a magnification of 40%. Data were statistically analyzed using Kolmogorov-Smirnov (KS) and Mann- Whitney tests.
Results: The average amount of leakage in the buccolingual and mesiodistal dimension were, 3.78±2.08 and 2.43±1.55 mm, respectively. There was statistically significant difference between the mean leakage of two dimensions (P=0.03).
Conclusion: Since the leakages in the buccolingual and mesiodistal dimensions were different, it was concluded that cutting direction could be an effective factor on the result of microleakage assessment.
Mansore Mirzaie, Esmaiel Yasini, Ladan Ranjbar Omrani, Morteza Rokni, Hojat Darvishpour ,
Volume 28, Issue 4 (1-2016)
Abstract
Background and Aims: Microleakage is a criterion proposed for assessing the success of any restorative material. Complete seal is difficult especially for dentin margins compared to enamel margins. The aim of this study was to assess the microleakage at the enamel and dentin margins of class V cavities restored by two GIs and two self-etch adhesive systems.
Materials and Methods: This study was done on forty third molars. Class V cavities (3×2×2mm) were prepared on the buccal and lingual surfaces of teeth using high speed handpiece with 0.8 mm diamond fissure burr. The occlusal margins of the cavities in the enamel and gingival margins were placed 1 mm below the CEJ. The teeth were divided into 4 groups and the bondings were cured for 20 sec and the teeth were restored. The specimens were kept in distilled water at the temperature of 37°C for 24 hrs. The teeth were thermo cycled and cut in buccolingual direction using diamond disc under water. The dye penetration was evaluated using a stereomicroscope and the leakage was scored. The scores were compared using Kruskal-Wallis test while the paired comparisons were done using Bonferroni correction. P≤0.05 was regarded as significant results.
Results: Microleakage scores were similar at the occlusal and gingival walls of all test groups. At the gingival walls, the least microleakage scores were observed. “Fuji IX + SE bond” group showed significant differences with the “Fuji IX + G bond” and “Nanoglass + G bond” groups (P≤0.05). At the occlusal walls, the least scores were observed in the “Fuji IX+SE bond” specimens which were significantly different from the other groups (P≤0.05).
Conclusion: Self-Cure glass ionomers yielded less microleakage scores compared to the different types of light-cures due to the less polymerization shrinkage.
Saeed Nemati Anaraki, Hamed Karkehabadi, Nazanin Zeinab Garshasb Zadeh,
Volume 29, Issue 1 (7-2016)
Abstract
Background and Aims: Microleakage is one of the most common problems in bonding systems, which cause different clinical shortcomings such as post operative sensitivity, marginal discoloration and pulp necrosis that can decrease those using bonding systems. The aim of this study was to compare the microleakage of three self etch bonding agents (generation 6 and 7) in class 5 composite cavities.
Materials and Methods: In this experimental study, 30 facial class 5 cavities were prepared in 30 human premolar teeth which were freshly extracted for orthodontic purposes. Cl V cavities were prepared in 2*3*2 mm dimensions. Occlusal margins were in enamel and gingival ones in cementum and randomly divided into 3 groups of 10 each. Then the cavities were treated by clearhil SE Bond (Kuraray, Japan), G Bond (GC, Japan), and Opti Bond Solo Plus (Kerr, USA), according to the manufacturers’ insductions. Then the cavities were filled using Z100 resin composite. The specimens were then immersed in a 50% AgNo solution for 24 hrs. Then, the teeth were cut buccolingually to be evaluated for dye penetration with stereomicroscope. Data were analyzed using Kruskal-Wallis test.
Results: This study revealed that Opti bond solo plus had type1 microleakage (dye penetration up to 1/3 of cavity) in 80% of specimen, and type 4 microleakage (along axial wall) in 10%. Clearfil SE bond had no leakage in 50%, type1 in 40% and type 2 (up to 2/3 of cavity) in 10%. But there was no significant difference in the microleakage at the gingival margins between 3 groups (P>0.05).
Conclusion: Clearfil SE Bond and G bond could prevent microleakage more effectively than that of Opti Bond Solo Plus on the occlusal margins. However, no difference in the microleakage on the gingival surfaces was found.
Mohammad Ali Keshvad, Tabassom Hooshmand,
Volume 29, Issue 2 (11-2016)
Abstract
Resin-based composite restorative materials have a substantial share in dental treatments. Their esthetic has made them patients’ first choice as restorative materials. Marginal leakage is one of their problems which leads to recurrent caries and post-operative hypersensitivity. Our aim was to evaluate the theoretical and clinical methods that have been proposed in the dental literature. Around 50 articles from Pubmed, SCOPUS and google scholar were selected and categorized in 4 groups based on the selected keywords. All the studies discussed in this paper have emphasized that there is no way to eliminate the microleakage but it can be reduced by means of some approaches. On the other hand, due to the multifactorial nature and difference of oral environment and laboratory conditions, there isn’t any certain way to define precisely. It seems that there is an absolute need for more research in this field to make the relation of theoretical results and clinical findings possible.
Esmail Yassini, Mansoureh Mirzaei, Bahar Safaei Yazdi, Zohreh Moradi,
Volume 30, Issue 3 (10-2017)
Abstract
Background and Aims: One of the main disadvantages of light cured composite resin materials is polymerization shrinkage upon curing. This leads to the microleakage of restoration and finally failure of the restoration. The purpose of this study was to investigate the effect of two types of light curing devices with different modes on the microleakage of posterior composite filling in Cl II restorations.
Materials and Methods: In this experimental study, 30 extracted sound molar human teeth were collected. All specimens were randomly divided into 3 groups of ten: Standard LED irradiation, pulse curing LED irradiation and QTH irradiation. All samples were prepared with mesial and distal boxes and composite fillings were done with three different light curing patterns for 20 s. After thermocycling, the specimens were kept in 2% methylene Blue solution for 24 h for microleakage test. After sectioning, the samples were evaluated by a stereomicroscope. For data analysis one-way ANOVA and Kolmogorov-Smirnov were used. P<0.05 was considered statistically significant.
Results: The quantitative tests showed that there were no statistical difference between study groups (P>0.05).
Conclusion: The results showed that both light curing devices were effective and no significant difference between different modes of LED light curing device on microleakage of class II composite restorations was found.
Fatemeh Mokhtari , Kazem Koopaei, Jalil Modaresi, Hamid Reza Hemati, Hengameh Zandi,
Volume 30, Issue 3 (10-2017)
Abstract
Background and Aims: The purpose of this study was to evaluate the sealing ability of MTA and cold ceramic by using bacterial leakage method.
Materials and Methods: In this experimental study, fifty human single root extracted teeth were chosen. In group A, 20 teeth were filled with MTA and in group B, 20 teeth were filled with cold ceramic. Five teeth were used as a positive control (obturated using gutta-percha without sealer), and five teeth were used as negative control (obturated using gutta-percha with AH26 sealer and coated with two layers of nail varnish). A bacterial leakage model utilizing Enterococcus faecalis was used for evaluation of the sealing ability. The teeth were placed in test tubes, so that they formed two upper and lower compartments. The cultured bacteria in the upper chamber were in contact with the coronal area of the tooth. The root end was placed in the lower chamber containing sterile culture media. In this case, the filling of the root canal was only the communication path between the upper and lower chambers. In this method, the presence of turbidity in the lower chamber indicated that bacteria had penetrated through barrier and reached the medium. The leakage was measured. The acquired data was analyzed using Chi-square test.
Results: In group A (MTA), 7 samples and in group B (Cold ceramic), 4 samples should the leakage. In regarding the leakage, there was no statistically significant difference between MTA and cold ceramic. (P=0.288)
Conclusion: The results showed that the sealing ability of MTA and cold ceramic was similar as root filling materials.
Abbasali Khademi, Seyed Amir Mousavi, Azizolah Moraditalab, Shirin Shahnaseri, Saber Khazaei, Reyhaneh Tajali,
Volume 31, Issue 1 (6-2018)
Abstract
Background and Aims: Microorganisms are the main cause of pulpal and periapical diseases. The most important failure factor is the lack of proper seals for the canal, resulting in microbial leakage. Therefore, the purpose of this study was to evaluate the sealing ability of ProRoot MTA and Bio MTA in canal obturation using fluid infiltration.
Materials and Methods: In this experimental study, 46 extracted mandibular premolar single canal teeth were used. After preparing and disinfecting the teeth with 3% sodium hypochlorite, their crowns were cut off from the cement-enamel junction. The teeth were then randomly divided into four groups: Group 1 (n=20) Bio MTA, Group 2 MTA ProRoot (n=20), negative and positive control groups, each of them contained 3 teeth. The preparation of teeth was performed using the step back method. The filled teeth were then evaluated by fluid filtration for leakage prevention. Data were analyzed by Mann-Whitney test and Tukey test (α=0.05).
Results: The results of statistical analysis showed that there was no significant difference between the MTA ProRoot and Bio MTA in sealing ability (P>0.05). That micro leakage is less in the Bio MTA group than in the ProRoot MTA group, but the difference was not significant.
Conclusion: This study showed that MTA ProRoot and Bio MTA can be used as appropriate canal filling materials.
Mohammad Javad Moghadas, Ehsan Rohani, Sara Majidinia, Najmeh Ojrati, Negin Vatanparast,
Volume 31, Issue 4 (1-2019)
Abstract
Background and Aims: The aim of the present study was to evaluate the effect of applying hydrophobic resin after use of different generation of the bonding systems on nanoleakage.
Materials and Methods: 20 third molar teeth were selected. The teeth were randomly divided into 4 groups of 5, each was treated using the fourth, fifth, sixth, and seven generation of dentin bonding. Then, the crown of teeth was sectioned from the CEJ region and each specimen was divided into two halves with mesiodistal cut, one half for the application of dentin bonding without the addition of a hydrophobic resin, and the other for the same dentin bonding by the addition of a hydrophobic resin. Afterwards, the specimens were restotred by composites. After placement of specimens in silver nitrate, the amount of nanoleakage was evaluated by SEM. Data were analyzed using a repeated measurement statistical analysis (α=0.05).
Results: The use of hydrophobic resins decreased nanoleakage and range of variations in all groups (P<0.05). This reduction was greater for total-etch dentin bonding. Higher degree of nanoleakage occurred in total-etch dentin bonding in most evaluated areas. In general, Clearfil S³ bond showed the least percent of the nanoleakage.
Conclusion: All dentin bonding systems showed some degree of reduction in nanoleakage after hydrophobic layer application and the reduction was greater in Total-etch adhesives systems.
Azadeh Zakerzadeh, Abdolrahim Davari, Haleh Karami,
Volume 33, Issue 2 (8-2020)
Abstract
Background and Aims: The self-adhering composites were introduced to reduce the chair time and minimizing handling errors. They can be bonded micromechanically to the dental structure without the need for separate adhesive application. Since there is limited information about bonding performance of this type of composite, the aim of this study was to evaluate the microleakage of enamel and dentin margins compared to the conventional adhesive systems.
Materials and Methods: 30 intact premolars were selected and on their buccal and lingual surfaces, standardized class V cavities with the occlusal margin in enamel and gingival margin in dentin were prepared. Then according to the materials used, the specimens were randomly divided into three groups including: 1) Vertise flow, 2) SE bond + ValuxTM Plus, and 3) Single bond + ValuxTM Plus. After final polishing of the restorations, the specimens were subjected to 1000 thermal cycles of 5±2 and 55±2°C and after that dye penetration was examined by stereomicroscope. The collected data were statistically analyzed using Kruskal-Wallis test and Mann-Whitney test
Results: The lowest rate of the occlosal microleakage was related to group 2 (P<0.05) and there was no significant difference between groups 1and 3 (P=0.58). Also, no significant difference was found in the gingival microleakage among the three groups (P=0.23). On the other hand, in each group, the gingival microleakage was significantly higher than occlosal margins (P<0.05).
Conclusion: According to the results, sealing ability of self-adhering composite is comparable with that of the conventional adhesives.
Alireza Daneshkazemi, Abdolrahim Davari, Zahra Usefi, Niloofar Fallah, Solmaz Ghanbarnejad, Pedram Daneshkazemi,
Volume 33, Issue 3 (10-2020)
Abstract
Background and Aims: Adding nanoparticles to dental composite resins, could reduce bacterial adhesion and secondary caries. Thermocycling can resemble in-vitro conditions to the oral environment. The aim of this study was to determine the effect of thermocycling on the microleakage of a mixture of copper oxide nanoparticles and flowable composite.
Materials and Methods: In this in-vitro study, 88 premolar teeth were divided into eight groups based on the application of copper oxide nanoparticles with concentrations of 0.1% and 0.3% w/w and thermocycling by 0, 1000, 5000 and 15,000 cycles. The occlusal grooves of the teeth were sealed with the mixture of flowable composite and copper oxide nanoparticles, and the teeth were thermocycled. Next, the teeth were immersed in methylene blue 2% solution for 24 hrs and were cut and the microleakage was evaluated by a stereomicroscope (hp/USA). Data were analyzed using Kruskal-Wallis and Mann-Whitney tests at the significance level of 0.05.
Results: In the groups with 0.1 % copper oxide nanoparticles, the mean microleakage increased significantly with increasing the number of thermocycling rounds (P=0.032). The difference in the microleakage between the groups exposed to 0 and 15,000 termocycling was significant (P=0.019). However, thermocycling had no significant effect on the microleakage of groups with concentration of 0.3% (P=0.780). The specimens subjected to the 0, 1000, 5000 and 15000 thermocycling in two concentrations of copper oxide nanoparticles showed no significant difference in the microleakage.
Conclusion: In groups containing copper oxide nanoparticles with a concentration of 0.1%, the microleakage increased by increasing the number of thermocycling up to 15,000 cycles compared to the control group. However, this did not have significant effect for the concentration of 0.3% copper oxide nanoparticles.
Fatemeh Mokhtari, Jalil Modaresi, Henghameh Zandi, Iman Ramezanian Nik,
Volume 34, Issue 0 (5-2021)
Abstract
Background and Aims: The need to use a highly effective sealer in order to create a complete seal along the canal is essential for the basic treatment of tooth roots. Therefore, the aim of this study was to investigate the sealing ability of cold ceramic and gutta-percha with sealer by applying the bacterial leakage and electrochemical method.
Materials and Methods: In this in-vitro experimental study, fifty human single-rooted teeth were selected and their crowns were cut from the cervical region. The canals were prepared and washed with 17% EDTA. Then the teeth were randomly divided into four groups: group 1 gutta-percha with AH26 sealer (Dentsply Detrey, Germany) (n=20), group 2 cold ceramic (Yazd, Iran) (n=20), negative and positive control groups which each consisted of 5 teeth. Samples were kept in an incubator at 37° C for 48 hrs. Two coats of nail polish were used for covering the root, except for the last 2 mm, and microleakage in the fillings was measured by the bacterial leakage and electrochemical methods. The microleakage of the two groups was statistically analyzed in the electrochemical technique by Student's t-test, and in the bacterial leakage method by Fisher's exact test.
Results: In bacterial leakage method, in the first group (gutta-percha) 7 samples (35%) and in the second group (cold ceramic) 3 samples (15%) had bacterial leakage, but no significant difference was observed between the two groups on different days (P>0.05). The mean microleakage based on the electrochemical technique in gutta-percha was significantly higher than that of cold ceramic (P=0.0001).
Conclusion: According to the lower microleakage values in the use of cold ceramic compared to gutta-percha, cold ceramic can be used to fill root canals to reduce microleakage, although further studies are needed.
Dr Gelareh Eblaghian, Dr Alireza Reyhani Mohamadi, Miss Maryam Kalantari Nezhad,
Volume 34, Issue 0 (5-2021)
Abstract
Background and Aims: Nowadays, the best choice for replacing missing teeth are dental implants, however, failure is not unexpected. One of the factors that plays an important role in the implant failure is bacterial microleakage which could cause biological complication. The aim of this study was to compare the bacterial microleakage between the two types of implants.
Materials and Methods: In the present interventional study, SPI and Dentis implants were placed bilaterally in the premolar-molar area of the patients' mandible. One day and 14 days after the delivery of the crown, by removing the crown and removing the abutment, sampling was performed using a sterile paper cone from four areas. One day after sample culturing, the number of colonies was counted. All data were entered into SPSS 23 and were analyzed using independent samples t-test and paired t-test with a significance level of 0.05. |
Results: The amount of bacteria in
implant sulcus was significantly different between the two types of implants (P=0.003). After 14 days, the amount of bacteria in SPI implant sulcus significantly decreased more than Dentis implant sulcus (P=0.001). After 14 days, the amount of bacteria also decreased in all other areas which there were no significant difference between the two types of implants (P>0.05).
