Showing 33 results for Bonding
Azita Kaviani, Asadoallah Ahmadzadeh, Maryam Zarei,
Volume 26, Issue 1 (3-2013)
Abstract
Background and Aims: Discoloration of resin composites is considered to be the major factor in esthetic restoration failures. The aim of this study was to evaluate the color stability of resin composites after rebonding with two different adhesive materials.
Materials and Methods: Forty five composite disc samples were divided into three groups (n=15). The surface of specimens was finished by polishing disc and rubber. In group 1, any additional phase was not performed. In group 2, composite discs were etched by %37 orthophosphoric acid, then Margin- bond was used for rebonding. In group 3, the etching procedure was in the same manner used for group 2, but Permaseal was used after etching. After the first phase of spectrophotometric measurement, the specimens were dipped in coffee mix for 3 weeks for aging the specimens. Then the second phase of spectrophotometric evaluation was performed. Collected data was analyzed using one-way ANOVA test followed by Tukey test. P<0.05 was considered as the level of significance.
Results: The mean total color difference (∆E) observed in groups 1 to 3 were 1.4±0.34, 5.24±1.51, and 7.44±1.34, respectively. Statistical significant differences were shown between the groups (P<0.001).
Conclusion: Rebonding with adhesive materials used in this study did not increase the color stability of composite restorations.
Lelya Sadighpour, Sousan Mir Mohammad Rezaei, Hamid Jalali, Shadab Rashtak,
Volume 26, Issue 4 (1-2014)
Abstract
Background and Aims: Retention and stability of the post and core system is the key factor for success of final restoration . The aim of this study was to evaluate the microtensile bond strength of the different composite core materials and bonding systems to a fiber post.
Materials and Methods: To evaluate the bond strength of the composite resins to a fiber post ( DT light post) 60 posts were divided into six groups : group A: Heliomolar Flow + Seal Bond, group B: Heliomolar Flow + SE Bond , group C: Valux Plus + Seal Bond , group D: Valux Plus + SE Bond , group E: Corecem + Seal Bond, group F: Corecem + SE Bond. All samples were thermocycled for 5000 cycles (5-55 0C) and cut into four bars for the microtensile bond strength test. Failure modes were identified using a stereomicroscope. Data were analysed using One-way ANOVA and Tukey HSD post hoc test (P<0.05).
Results: The interaction between composite resin materials and bonding systems were positive. The conventional hybrid composite (Valux Plus) had significantly higher bond strength compared with the core specific flowable composite (Corecem) when Seal Bond was applied as bonding agent (P<0.05). However, when SE Bond was utilized hybrid composite demonstrated significantly lower bond strength than that of other two groups (P<0.05).
Conclusion: The performance of a particular composite is affected by the bonding system that is applied. A single composite resin may have different bond strength when combined with different bonding system.
Salari Behzad , Shahabi Sima , Bagheri Hossein , Yousefi Mahsa ,
Volume 26, Issue 4 (1-2014)
Abstract
Background and Aims : The aim of this study was to evaluate the effect of chlorhexidin 2%, sodium hypochlorite 2.5% and hydrogen peroxide 3% as three effective and regular disinfectants on the microleakage of 7th generation bonding agents in vitro.
Materials and Methods: 45 extracted molar teeth without carries were collected and disinfected. On buccal and lingual aspects of these teeth conventional class V cavity preparation were done (90 cavities), then randomly divided to 4 groups, three of them had 10 teeth (20 cavities) and one of them had 5 teeth (10 cavities) as control group. Cavities in each experimental group prepared with one of the disinfectants and then 7th generation bonding (Optibond all in one, kerr) was used as noted by manufacturer, then cavities filled with composite and polished. Bonding agent was used without our previous disinfectants manipulation in control group. Specimens were thermocycled with 1000 thermal cycles between 5 and 55 0 C each for 30 seconds and then immersed in the methylene blue 5%, then sectioned mesiodistally and investigated for microleakage under stereomicroscope (Olympus, Japan). Data were analyzed using Kruskal-Wallis and Wilcoxon mean rank tests.
Results: Despite the lower mean rank values for the untreated group at both occlusal and gingival aspects, the Kruskal-Wallis procedure (α=0.05) showed that the treatment factor did not significantly affect the mean rank values neither in occlusal (P=0.12) nor in gingival (P=0.39) part of cavities.
Conclusion: According to the results of this study, antimicrobial agents such as chlorhexidine 2%, sodium hypochloride 2.5% and hydrogen peroxide 3% can be used perior to 7th generation dentin bonding agent
(Optibond all in one, kerr) without much concern.
Narges Dorri, Azita Kaviani, Ali Noori,
Volume 27, Issue 2 (6-2014)
Abstract
Background and Aims: The ability of composite restorations to prevent microleakage needs desirable bonding material for proper sealing . The purpose of this study was to evaluate class V composite restorations microleakage in premolars with/without electric current while applying variant dentin bonding in vitro.
Materials and Methods: 120 non-carious human premolars were used for this study and standardized class v cavities were prepared. The tooth roots were cut by discs at a distance of 5 mm from CEJ and pulp tissue was removed. The teeth were divided into six groups of 20. In the first group, electric current was applied, Single bond (3M ESPE, St Paul, MN, USA) with a broom motion attached to the cathode and a sponge containing bonding was used as anode. The used current was 15µA and the Single bond in the second group was used without electricity. Then two bondings PQ1 (Ultradent, Germany) and Optibond solo plus (Kerr, USA) were used with and without electricity. After adhesive application and curing the bonding agents, cavities were restored by a composite (Valux Plus). The root ends were sealed by wax and all teeth surfaces, except 1 mm around the restorations were covered with a nail varnish. The specimens were thermocycled for 1000 cycles and placed in fushin for 24 hours and were then sectioned vertically and examined under a stereomicroscope. Data were scored on a 0-4 scale based on microleakage at the gingival margins and analyzed using Kruskal-Wallis and Mann-whitney test.
Results: Based on the results, the extent of microleakage in the groups of electric current was significantly less than the groups without using the electric current (P=0.05). The lowest degree of microleakage was found in PQ1 group, and the greatest difference between the groups with and without electricity was also found in PQ1 group. Single bond and Optibond Solo Plus with electric current showed a lower degree of microleakge.
Conclusion: The result showed that use of electric current during the application of dental adhesives could reduce the extent of microleakage.
Mehdi Araghbidikashani, Elham Esmaili, Gholamreza Eslami, Mohsen Nuori, Hasan Ghaffari, Abbas Salehi,
Volume 28, Issue 2 (7-2015)
Abstract
Background and Aims: The aim of this descriptive longitudinal study was to determine the type of teeth that were more prone in accidental bracket debonding and also to investigate the relationship between broken bracket bond and intervening factors such as age, type of malocclusion and sex.
Materials and Methods: We used a pilot study to determine the correct sample size for this study. According to the pilot study which consisted of 20 records of patients, it was concluded that 576 patient’ records was needed. The mean time for a bracket before it fails was also measured using Kaplan-Meier method. Cox regression analysis was done to examine the effect of age, gender, and class of malocclusion on each tooth with broken bracket. Data were analyzed using the software SPSS 20.
Results: Results showed that the percentage of unexpected broken bracket bond for each tooth varied and they were significantly related only in second premolars in both jaws with malocclusion that was different for each tooth (P=0.037, P=0.004).
Conclusion: Maxillary second premolars and mandibular second premolars had the highest rate of unexpected broken bracket bond in CL II CL I malocclusion respectively. Age, gender and malocclusion had no effect on the unexpected broken bracket bond for other teeth.
Alireza Daneshkazemi, Abdolrahim Davari, Farnaz Farahat, Neda Pazhoohi,
Volume 28, Issue 2 (7-2015)
Abstract
Background and Aims: The purpose of this study was to compare the effect of chlorhexidine 2%, ethanol 70% and sodium ascorbate 10% and delayed bonding for 1 week on the shear bond strength of composite resin to enamel after bleaching.
Materials and Methods: 90 human central incisors were divided into 6 equal groups: Group 1: no bleaching Group 2: bleaching with carbamide peroxide 45% for 45 minutes Group 3: bleaching + restoring specimens in distilled water for 1 week. In group 4, 5 and 6, after bleaching, 1 cc of chlorhexidine 2%, ethanol 70% and sodium ascorbate 10% were applied for 15 minutes. Composite cylinders were bonded on the buccal surfaces. Specimens were thermocycled for 1000 cycles and the shear bond strength test was done. Specimens were examined under stereomicroscope and SEM. Data were analyzed a sign ANOVA and Bonferroni test.
Results: The shear bond strength values were not significantly lower in the bleached teeth (group 3, 4, 5 and 6) than that of negative control group (group 1) (P=1.000, P=0.069, P=0.081, P=1.000) Bonferroni test results show significant difference between test groups (3, 4, 5 and 6) and group 2 (P<1.000, P=0.007, P=0.008, P<1.000) Under SEM, resin tags in group 2 was thinner and lesser than group 3, 4, 5 and 6. The most adhesive failures were in group 2.
Conclusion: Bleaching with carbamide peroxide and immediate bonding of composite decreased the shear bond strength. Sodium ascorbate 10% and delayed bonding for 1 week were the most effective way.
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.
Mostafa Ghandi, Babak Namvar, Sotodeh Davaie,
Volume 28, Issue 4 (1-2016)
Abstract
Background and Aims: As in fissure sealant therapy the tooth surface is mostly enamel, the use of an enamel bonding agent (hydrophobic bonding agent) may be more cost effective than that of newer generations of bonding (hydrophilic bonding agents). The aim of this study was to compare the retention and durability of fissure sealant therapy when applying an enamel bonding agent, a dentin bonding agent and no bonding agent during 4 years.
Materials and Methods: This study was done on the first permanent molars of the upper and lower jaws of 24 students of the first grade of a primary school (6-7 years old). On 36 teeth, a dentin bonding agent (Excite) was applied under the fissure sealant and on 36 teeth an enamel bonding agent (Margin bond) was applied under the fissure sealant. Then, 24 teeth were selected from these two groups and were compared with a group (including 24 teeth) with no bonding agent under the fissure sealant (as control group). All the fissures of the teeth were evaluated annually for 4 years to find out the presence or absence of fissure sealant substance. Data were analyzed using Wilcoxon test.
Results: From the statistical analysis, there was no significant difference in retention and durability of the fissure sealant substance comparing the group with dentin bonding agent (Excite) and the group with enamel bonding agent (Margin bond). Also, using a bonding agent made no significant difference (P>0.05).
Conclusion: According to the results of this study, using a bonding agent made no improvement in the retention and durability of fissure sealant substance.
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.
Rahim Asghari Salavat, Ahad Samadi,
Volume 30, Issue 3 (10-2017)
Abstract
Background and Aims: Poor adhesion between porcelain and some of the dental alloys is one of the most challenges to select the desirable alloy in dental restorations. Therefore, the aim of this study was to evaluate the bond strength of porcelain to some of the commercial alloys. This can help in selection of desirable alloy.
Materials and Methods: The shear bond strength of porcelain to the three of the most widely used nickel-base dental alloys commercially named as: Verabond, Damcast and Noritake were evaluated according to standard ASTM E4. The results were analyzed based on the statistical method of independent t with the meaningful level of P<0.05. Then, the bonding interface of the fired samples was evaluated using SEM equipped with EDX analyzer and X-ray diffractometry.
Results: The average bonding strength of porcelain to each of the above mentioned alloys were determined as: 27.54±5.48, 22.46±4.99 and 26.18±4.27 MPa, respectively. Due to the existence of Be and Al in the chemical composition of Verabond and Damcast and their higher appetencies to form the different surface oxides in preference to Cr2O3, not only the bond strength of porcelain to two these alloys was increased about 20 percent (compared with the Noritake), but also the color of their porcelain was not changed.
Conclusion: To replace the replacing of deleterious elements from the chemical composition of dental alloys. The added new elements should control through the oxide layer and the formation of Cr2O3 in porcelain-alloy interfaces for adequate bond strength.
Ramin Mosharraf, Aref Sadeghian,
Volume 31, Issue 3 (11-2018)
Abstract
Background and Aims: In endodontically treated teeth, the fiber posts are used to retain a core restoration. The purpose of this study was to evaluate the effect of different resin cements on the bond strength of fiber reinforced composite posts to root canal dentin, and comparing the bond strength in different sections of root.
Materials and Methods: In this in-vitro experimental study, 48 extracted single-canal central incisors were endodontically treated. For the push out test, the posts were divided into 3 groups according to one of the following three different cement materials (n=16) (Bifix SE, Bifix QM, Rebilda). Three slices with a thickness of 2-mm were prepared of each root. The push-out tests were performed at a cross-head speed of 1 mm/minute using a universal testing machine. Data were analyzed by two-way and one-way ANOVA test followed by Tukey post hoc test (α=0.05).
Results: There was no significant differences between the mean push out bond strength of three experimental groups (P=0.650), but there were significant differences between the mean push out bond strength of root dentin regions (P<0.001).
Conclusion: Under the conditions of this study, there was no significant difference between the mean push out bond strength of 3 different resin cement systems. The coronal region of root dentin showed significantly higher mean bond strength values than that of the middle and apical thirds.
Sania Azizi, Sepide Arab, Shima Younespour, Atefe Saffar Shahroudi,
Volume 37, Issue 0 (3-2024)
Abstract
Background and Aims: One side effect of orthodontic treatment is microcrack formation during debonding process. Since the type of ligation may affect the applied debonding force, this study was conducted to investigate the effect of ligation method on the enamel microcrack formation following debonding of orthodontic brackets.
Materials and Methods: The present study was an experimental in vitro study. 69 extracted human premolar teeth were divided into 3 groups with 23 teeth by a simple random method. A bracket was bonded on the buccal surface of the teeth, then the desired tooth was placed in a typodont where the rest of the teeth were mounted. Then, the arch wire was passively placed in the bracket slot. The samples were ligated by one of these three methods based on the study group: 1. Oring ligation 2. Tight ligation with a wire ligature for each tooth separately 3. Ligation of all arch teeth together, using a wire ligature. The buccal surfaces of the teeth were observed under a stereomicroscope and the length, location, and the number of microcracks were recorded before and after debonding process. In order to analyze the data, generalized estimating equation analysis was used.
Results: In all three groups, a significant increase was observed in the average total length and number of enamel microcracks following the debonding process. (P<0.001 in all three groups), with no statistically significant difference between the three study groups. However, it was greater in group 2 than that of groups 3 and 1 respectively. In general, the number of new cracks was more in mid-buccal area followed by cervical and occlusal areas.
Conclusion: The debonding process caused an increase in the average total length as well as the number of enamel microcracks. Type of ligation might affect the enamel microcrack formation so that in tight ligation group we had the greatest increase in the enamel damage especially in mid-buccal area of the tooth. Tight ligation method can cause more enamel cracks than O-ring ligation and full arch ligation methods.
Elahe Soltanmohamadi Borujeni, Ali Bavi, Mohammad Aghaali, Ali Saleh, Aida Mehdipour,
Volume 37, Issue 0 (3-2024)
Abstract
Background and Aims: Strong bond between the ceramic brackets and ceramic veneers has an important role in cosmetic treatment. The purpose of this study was to investigate the effect of aging on the shear bond strength (SBS) of ceramic brackets bonded to zirconia after surface preparation by Neodymium-doped Yttrium Aluminum Garnet (Nd: YAG) laser or sandblasting with alumina.
Materials and Methods: This experimental study was conducted on 24 zirconia blocks and these blocks were randomly divided into two groups for surface preparation and each was sub-divided into three time intervals. Surface preparation was done by sandblasting with alumina: in SG1 (Immediately after sandblasting), SG2 (2 weeks after sandblasting), and SG3 (3 months after sandblasting) groups. For the Nd: YAG laser (1/5W, 20Hz, 10s) with non-contact mode: in LG4 (Immediately after laser), LG5 (2 weeks after laser), and LG6 (3 months after laser) groups. The ceramic brackets were bonded to the zirconia blocks. The SBS and adhesive remnant index (ARI) were evaluated and compared among test groups. Dara were analyzed using Mann Whitney test.
Results: There was no significant difference between the SBS of SG1 and LG4 (P=0.430), SG2 and LG5 (P=0.382) and SG3 and LG6 (P=0.326) groups. LG4 group showed the highest shear bond strength. After aging (2 weeks and 3 months), the laser groups showed higher SBS. There was no significant difference in the ARI between SG1 and LG4 (P=0.220), SG2 and LG5 (P=0.154), SG3 and LG6 (P=0.527) groups.
Conclusion: No significant difference was observed between the Nd: YAG laser and sandblasted groups in terms of SBS and ARI over time. Therefore, Nd: YAG laser could be used as a surface treamnet method in Zirconia crowns for bonding to ceramic brackets.
