In vitro comparison of polymerisation kinetics and the micro-mechanical properties of low and high viscosity giomers and RBC materials
| Autor: | Nicoleta Ilie, Garry J.P. Fleming |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
Curing Lights
Dental Materials science Viscosity Composite number Modulus Young's modulus Composite Resins Polymerization Dental Materials symbols.namesake Elastic Modulus Indentation Phase (matter) Materials Testing Vickers hardness test symbols Methacrylates Bisphenol A-Glycidyl Methacrylate Glass Irradiation Composite material General Dentistry Light-Curing of Dental Adhesives |
| Zdroj: | Journal of Dentistry. 43:814-822 |
| ISSN: | 0300-5712 |
| Popis: | The study aims to characterise a low and high viscosity giomer bulk fill resin restorative with established low and high viscosity resin-based composite (RBC) restoratives at simulated clinical relevant specimen depths.The irradiance of a light curing unit (Bluephase 20i) was measured on a laboratory-grade spectrometer at distances up to 10mm from the light tip (in 1mm increments). Polymerization kinetics (real-time decrease of CC double bond and degree of cure, DC) and micro-mechanical properties (Vickers hardness/HV; Depth of cure/DOC; Indentation modulus/E) were assessed at varying specimen depths (0.1-6mm in 100μm steps for E, DOC and HV and 0.1, 2, 4 and 6mm for DC) for a 20s irradiation.One and two-way ANOVA (α=0.05) were performed. The parameter material has a significant (p0.001) effect on DC (ηP(2)=0.839), HV (ηP(2)=0.683), and E (ηP(2)=0.536), whereas the specimen depth influenced only DC (ηP(2)=0.584) but not HV (p=0.093) or E (p=0.133). The polymerisation kinetic could be described by an exponential sum function, distinguishing between the gel and the glass phase. The hardness drop out was lower than 20%, indicated a depth of cure of 6mm for all materials.The low and high viscosity giomer bulk-fill restoratives fulfil the requirements of bulk-fill placement, since under the analysed irradiation conditions an adequate depth of cure of4mm was identified. Variation of DC with specimen depth was low, with little variation at specimen depths of4mm. The micro-mechanical properties of the giomer materials were higher compared with the conventional RBC materials. |
| Databáze: | OpenAIRE |
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