Principles of Analytical Chemistry for Toxicology

Durner, Jürgen; Watts, David C.

doi:10.1007/978-3-642-35374-1_91

Cited by 1 publication

(1 citation statement)

References 63 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The CTE of organic monomers ranges between 110 and 190 × 10 -6 /°C 32,65 and between 0.16 and 0.73 × 10 -6 /°C for inorganic glass fillers 66 where S-Glass has a CTE of 0.16 × 10 -6 /°C. The lower CTE for Gr-B and Gr-C is attributed towards (i) a higher degree of conversion 67 and (ii) randomly oriented rigid glass fibres preventing the free monomer movement, similar to an earlier study 27 . A higher degree of conversion results in an increased number of carbon-carbon covalent bonds between the polymer chains and this increased cross-linking reduces the polymer chain movement at higher temperatures.…”

Section: Discussionsupporting

confidence: 87%

Dimensional stability of short fibre reinforced flowable dental composites

Raju

Rajan

Farrar³

et al. 2021

Sci Rep

View full text Add to dashboard Cite

Fibre-reinforced dental composites are proven to have superior mechanical properties in comparison with micro/nano/hybrid filled composites. However, the addition of small quantities of short glass fibres could affect the dimensional stability of the restoration both during initial stages as well as through the life of the restoration. This in-vitro study aims at evaluating the physical properties of short S-Glass reinforced flowable dental composites. Two S-Glass short fibre-particulate reinforced (5 wt% of aspect ratios 50 and 70) and one particulate only reinforced flowable dental composites were prepared with UDMA-TEGDMA based dental monomer systems. Samples were photopolymersied for 60 s and stored in distilled water at 37 °C for 24 h before testing. Depth of cure (through-thickness microhardness), volumetric shrinkage (Archimedes technique), polymerisation stress (cantilever based tensometer), curing exotherm (thermocouple), water sorption and solubility (ISO 4049) and thermal expansion coefficient (dilatometer) were determined. The test results were statistically analysed using one-way ANOVA (p < 0.05). Depth of cure increased by 41%, volumetric shrinkage increased by 8.3%, shrinkage stress increased by 37.6%, exotherm increased by 20.2%, and thermal expansion reduced by 6.4% while water sorption and solubility had a negligible effect with the inclusion of short glass fibres. The study demonstrates that within the same organic resin system and quantity, a small replacement of fillers with short fibres could significantly affect the dimensional stability of the composite system. In conjunction with mechanical properties, this study could help clinicians to gain confidence in fibre reinforced dental composite restorative system.

show abstract