Browsing by Author "Parker, Raeesa"

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    Cuspal deflection of teeth restored with bulk fill flowable composite resins, with and without fiber-reinforcement and evaluated by Micro-computed Tomography
    (Elsevier Methods X, 2023-07-27) Parker, Raeesa; Mulder, Riaan; Keanly, Colin
    Polymerisation shrinkage of composite resins is a clinical challenge which has been well documented in the literature. Many studies investigating polymerisation shrinkage stress measure cuspal deflection, which is a manifestation of this stress. The introduction of flowable bulk-fill composite (BFRBC) materials has streamlined the restorative process, though the shrinkage and cuspal deflection from these BFRBCs has not been compared with regards to its use with polyethylene fibers (Ribbond fibers). The authors describe a method to measure the cuspal deflection of flowable BFRBCs placed in cavities of standardised dimensions at distinct steps of the restorative process, with and without fiber-reinforcement and using x-ray micro-computed tomography. Coordinate points are established on the buccal and lingual aspects of scanned specimens using the Volume Graphics VG Studio max 3.2.5 (Hiedelberg, Germany 2018) software. The system allows for these landmarks to be established across each scan (of the same tooth), ensuring standardization of each specimen. Further anatomical points are used to enable analysis. Comparison of angles generated across these points determines the extent of cuspal deflection. •A method of measuring the cuspal deflection of composite resins is proposed. •Experimental procedures are provided. •Data analysis methods are outlined.
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    Cuspal deflection of teeth restored with bulk fill flowable composite resins, with and without fiber-reinforcement and evaluated by Micro-computed Tomography.
    (University of the Western Cape, 2024) Parker, Raeesa; Mulder, Riaan
    Background: With the development of bulk-fill flowable composites, dentists are increasingly opting to dispense of the time-consuming layering required of conventional universal composites. It has been suggested that a reduction in cuspal deflection can be expected when modifications to the interfacial stress concentrations in large composite restorations are introduced. It has further been demonstrated that fiber-reinforced composite restorations reduce stress accumulation on the remaining hard tissue. Aim: To determine the cuspal deflection of teeth restored with bulk fill flowable composite resins, with and without fiber-reinforcement and evaluated by micro-computed tomography. Methods and Materials: A comparative in vitro study was designed utilizing micro-CT scanning. Standardized mesio-occlusal-distal (MOD) preparations restored with three different bulk fill flowable composite resin systems, with and without Ribbond fiberreinforcement, were assessed and compared. The flowable bulk fill composites tested in this study were Filtek Bulk Fill (3M), Palfique Bulk Flow (Tokuyama) and Tetric N-Flow (Ivoclar Vivadent). Scans were after fiber placement (uncured), the tooth after curing of the fiber, the tooth after placement of the composite (uncured) and lastly, the tooth after curing of the composite. Scanned data were analyzed using Volume Graphics VG Studio Max 3.2.5 (Nagoya, Japan). The mechanical properties of these materials and the influence of Ribbond fibers on compressive strength was evaluated by means of catastrophic compressive strength testing.