Effect of Cyclic Loading on Shear Bond Strength of Orthodontic Brackets: An In Vitro Study
Objectives: In clinical conditions, orthodontic brackets are exposed to periodic stresses mainly induced by mastication and intraoral forces. The objective of the present study was to evaluate the effects of cyclic loading to simulate masticatory forces on shear bond strength (SBS) of metal brackets...
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| Format: | Article |
| Language: | English |
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Tehran University of Medical Sciences
2018-11-01
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| Series: | Frontiers in Dentistry |
| Subjects: | |
| Online Access: | https://jdt.tums.ac.ir/index.php/jdt/article/view/2734 |
| _version_ | 1811259950315339776 |
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| author | Mohammad Moslem Imani Farzaneh Aghajani Nafiseh Momeni Mohammad Sadegh Ahmad-Akhoundi |
| author_facet | Mohammad Moslem Imani Farzaneh Aghajani Nafiseh Momeni Mohammad Sadegh Ahmad-Akhoundi |
| author_sort | Mohammad Moslem Imani |
| collection | DOAJ |
| description | Objectives: In clinical conditions, orthodontic brackets are exposed to periodic stresses mainly induced by mastication and intraoral forces. The objective of the present study was to evaluate the effects of cyclic loading to simulate masticatory forces on shear bond strength (SBS) of metal brackets bonded to teeth using self-etch and total-etch bonding systems.
Materials and Methods: Eighty-four caries- and crack-free bovine mandibular incisors were selected and randomly assigned to two groups based on the type of bonding system. After bonding, all samples were thermocycled (500 cycles) followed by cyclic loading of the half of the specimens in each group by applying 40 N load with 2 Hz frequency for 10,000 cycles. The SBS was measured using a universal testing machine. The adhesive remnant index (ARI) score was calculated subsequently. Data were analyzed using Kolmogorov-Smirnov test, two-way ANOVA and Mann-Whitney test.
Results: The SBS was 10.09±3.78 MPa and 14.44±6.06 MPa for self-etch and total-etch bonding systems in cyclic loading group, respectively. The SBS was 9.43±5.3 MPa and 11.31±5.42 MPa in self-etch and total-etch groups without cyclic loading, respectively. Cyclic loading did not cause any significant difference in SBS (P>0.05). The ARI scores of the groups were significantly different (P<0.05).
Conclusions: The present results demonstrated that low masticatory forces at 10,000 cycles did not have a significant impact on bracket-adhesive SBS; however, they significantly changed the ARI score. Even though the total-etch bonding system yielded higher SBS than the self-etch system, the performance of both was clinically acceptable. |
| first_indexed | 2024-04-12T18:39:14Z |
| format | Article |
| id | doaj.art-ff799696a84f4e4094b2b3c29727fbbf |
| institution | Directory Open Access Journal |
| issn | 2676-296X |
| language | English |
| last_indexed | 2024-04-12T18:39:14Z |
| publishDate | 2018-11-01 |
| publisher | Tehran University of Medical Sciences |
| record_format | Article |
| series | Frontiers in Dentistry |
| spelling | doaj.art-ff799696a84f4e4094b2b3c29727fbbf2022-12-22T03:20:50ZengTehran University of Medical SciencesFrontiers in Dentistry2676-296X2018-11-011562734Effect of Cyclic Loading on Shear Bond Strength of Orthodontic Brackets: An In Vitro StudyMohammad Moslem Imani0Farzaneh Aghajani1Nafiseh Momeni2Mohammad Sadegh Ahmad-Akhoundi3Assistant Professor, Department of Orthodontics, School of Dentistry, Kermanshah University of Medical Sciences, Kermanshah, IranDental Research Center, Dentistry Research Institute, Department of Dental Biomaterials, School of Dentistry, Tehran University of Medical Sciences, Tehran, IranDentist, Dental Research center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, IranProfessor, Dental Research Center, Dentistry Research Institute, Department of Orthodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, IranObjectives: In clinical conditions, orthodontic brackets are exposed to periodic stresses mainly induced by mastication and intraoral forces. The objective of the present study was to evaluate the effects of cyclic loading to simulate masticatory forces on shear bond strength (SBS) of metal brackets bonded to teeth using self-etch and total-etch bonding systems. Materials and Methods: Eighty-four caries- and crack-free bovine mandibular incisors were selected and randomly assigned to two groups based on the type of bonding system. After bonding, all samples were thermocycled (500 cycles) followed by cyclic loading of the half of the specimens in each group by applying 40 N load with 2 Hz frequency for 10,000 cycles. The SBS was measured using a universal testing machine. The adhesive remnant index (ARI) score was calculated subsequently. Data were analyzed using Kolmogorov-Smirnov test, two-way ANOVA and Mann-Whitney test. Results: The SBS was 10.09±3.78 MPa and 14.44±6.06 MPa for self-etch and total-etch bonding systems in cyclic loading group, respectively. The SBS was 9.43±5.3 MPa and 11.31±5.42 MPa in self-etch and total-etch groups without cyclic loading, respectively. Cyclic loading did not cause any significant difference in SBS (P>0.05). The ARI scores of the groups were significantly different (P<0.05). Conclusions: The present results demonstrated that low masticatory forces at 10,000 cycles did not have a significant impact on bracket-adhesive SBS; however, they significantly changed the ARI score. Even though the total-etch bonding system yielded higher SBS than the self-etch system, the performance of both was clinically acceptable.https://jdt.tums.ac.ir/index.php/jdt/article/view/2734Shear StrengthDental BondingOrthodontic BracketsBite Force |
| spellingShingle | Mohammad Moslem Imani Farzaneh Aghajani Nafiseh Momeni Mohammad Sadegh Ahmad-Akhoundi Effect of Cyclic Loading on Shear Bond Strength of Orthodontic Brackets: An In Vitro Study Frontiers in Dentistry Shear Strength Dental Bonding Orthodontic Brackets Bite Force |
| title | Effect of Cyclic Loading on Shear Bond Strength of Orthodontic Brackets: An In Vitro Study |
| title_full | Effect of Cyclic Loading on Shear Bond Strength of Orthodontic Brackets: An In Vitro Study |
| title_fullStr | Effect of Cyclic Loading on Shear Bond Strength of Orthodontic Brackets: An In Vitro Study |
| title_full_unstemmed | Effect of Cyclic Loading on Shear Bond Strength of Orthodontic Brackets: An In Vitro Study |
| title_short | Effect of Cyclic Loading on Shear Bond Strength of Orthodontic Brackets: An In Vitro Study |
| title_sort | effect of cyclic loading on shear bond strength of orthodontic brackets an in vitro study |
| topic | Shear Strength Dental Bonding Orthodontic Brackets Bite Force |
| url | https://jdt.tums.ac.ir/index.php/jdt/article/view/2734 |
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