Adhesion of orthodontic brackets to indirect laboratory-processed resin composite as a function of surface conditioning methods and artificial aging |
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| Authors: | Emir Yüzba??o?lu Gül?ilay Sayar-Torun Mutlu Özcan |
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| Affiliation: | 1. Department of Prosthodontics, School of Dentistry, ?stanbul Medipol University, ?stanbul, Turkey;2. Biomaterials and Translational Dental Research Laboratory, Regenerative and Restorative Medical Research Center (REMER), Istanbul Medipol University, Istanbul, Turkeyeyuzbasioglu@medipol.edu.tr;4. Department of Orthodontics, School of Dentistry, ?stanbul Medipol University, ?stanbul, Turkey;5. Dental Materials Unit, Center for Dental and Oral Medicine, Clinic for Fixed and Removable Prosthodontics and Dental Materials Science, University of Zurich, Zurich, Switzerland;6. Biomaterials and Translational Dental Research Laboratory, Regenerative and Restorative Medical Research Center (REMER), Istanbul Medipol University, Istanbul, Turkey |
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| Abstract: | This study compared the shear bond strength of orthodontic brackets to laboratory-processed indirect resin composites (IRC) after different surface conditioning methods and aging. Specimens made of IRC (Gradia Indirect, GC) (thickness: 2 mm; diameter: 10 mm) (N = 80) were randomly assigned to one of the following surface conditioning methods: C – Control: no treatment; AA – Air-abrasion (50 μm Al2O3 particles); DB – Diamond bur and HF – Etching with hydrofluoric acid (9.6%). After adhesive primer application (Transbond XT), orthodontic brackets were bonded to the conditioned IRC specimens using adhesive resin (Transbond XT). Following storage in artificial saliva for 24 h at 37 °C, the specimens were thermocycled (×1000, 5–55 °C). The IRC–bracket interface was loaded under shear in a Universal Testing Machine (0.5 mm/min). Failure types were classified using modified adhesive remnant index criteria. Data were analyzed using two-way ANOVA and Tukey`s HSD (α = 0.05). Surface conditioning method did not significantly affect the bond strength results (p = 0.2020), but aging significantly decreased the results (p = 0.04). Interaction terms were not significant (p = 0.775). In both non-aged and aged conditions, non-conditioned C group presented the lowest bond strength results (MPa) (p < 0.05). In non-aged conditions, surface conditioning with DB (8.03 ± 0.77) and HF (7.87 ± 0.64) showed significantly higher bond strength results compared to those of other groups (p < 0.05). Thermocycling significantly decreased the mean bond strength in all groups (2.24 ± 0.36–6.21 ± 0.59) (p < 0.05). The incidence of Score 5 (all adhesive resin remaining on the specimen) was the highest in HF group without (80%) and with aging (80%) followed by DB (40, 70%, respectively). C groups without and with aging showed exclusively Score 1 type (no adhesive resin on the specimen) of failures indicating the least reliable type of adhesion. |
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| Keywords: | Adhesion aging bond strength indirect resin composite orthodontic brackets surface conditioning |
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