Browsing by Author "Lynch, E."
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Item Metadata only 1H NMR investigations of the molecular nature of cobalt (II) ions in human saliva(Elsevier, 2012) Chang, H.; Tomoda, S.; Silwood, C.; Lynch, E.; Grootveld, MartinHigh-resolution 1H NMR spectroscopy demonstrated that addition of Co(II) ions to isolated human salivary supernatants (HSSs) gave rise to its complexation by a variety of biomolecules. The relative efficacies of these complexants/chelators in this context were classifiable by the influence of added Co(II) on their line-widths and chemical shift values, and also the added Co(II) concentration-dependence of these spectral modifications. Those which were most affected by the addition of this metal ion were lactate > formate histidinate > succinate, this order reflecting the ability of these complexants to compete for the available Co(II) in terms of (1) thermodynamic equilibrium constants for the ormation of their complexes and (2) their HSS concentrations. Since many of these HSS Co(II) complexants (particularly lactate,formate and histidine) serve as powerful OH cavengers, the results acquired indicate that any of this radical generated from the Co(II) source in such complexes via pseudo-Fenton reactions may be ‘sitespecifically’ scavenged. The significance of these observations regarding the in vivo corrosion of cobaltcontaining metal alloy dental prostheses (e.g., Co–Cr alloys), the availability of trace levels of this metal ion in human saliva, and cobalt toxicity, is discussed.Item Metadata only A spectrophotometric study on light attenuation properties of dental bleaching gels: potential relevance to irradiation parameters.(MDPI, 2020-12-16) Anagnostaki, E.; Mylona, V.; Parker, S.; Kosma, K.; Chala, M.; Cronshaw, M.; Dimitriou, V.; Tartarakis, M.; Papadogiannis, N.; Lynch, E.; Grootveld, MartinBackground: During in-office bleaching, appropriate light sources are applied in order to enhance the activity of the bleaching gels applied onto teeth. For this method to be effective, a high absorption of light within the gel is necessary. Variation in the light attenuation capability of the gel, the duration of application and light activation can contribute towards safety hazards associated with this procedure. Methods: In this study, seven different gels and hydrogen peroxide have been evaluated for their optical properties by means of spectrophotometry (440–1000 nm). The transmitted light spectrum was used to estimate the intensity loss for each gel. The mean intensity decreases observed were statistically analysed using an analysis of variance (ANOVA). Results: The five more-pigmented gels tested indicated a very similar intensity loss of around 80%, whereas the remaining two gels showed significantly less attenuation (predominantly, p < 10−6). Conclusions: Throughout the spectrum of wavelengths examined, and according to the underlying studies evaluated, five of the gels assessed demonstrated an attenuation high enough to possibly avoid overheating of the underlying enamel dentine and pulp. An evaluation of appropriate irradiation parameters is proposed.Item Metadata only High-resolution 1H NMR investigations of the oxidative consumption of salivary biomolecules by a tooth-whitening formulation: relevance to safety issues.(Scientific Research Publishing, 2012) Chan, W.; Banks, R.; Lynch, E.; Grootveld, MartinItem Metadata only High-resolution 1H NMR investigations of the oxidative consumption of salivary biomolecules by oral rinse peroxides(Informa, 2013) Chang, H.; Silwood, C.; Lynch, E.; Grootveld, MartinItem Metadata only Oxidative Consumption of oral biomolecules by therapeutically-relevant doses of ozone.(Scientific Research Publishing, 2012) Chang, H.; Lynch, E.; Grootveld, MartinItem Metadata only Tooth-whitening activity of a novel home-bleaching system utilising thermal diffusion: a multifactorial simultaneous evaluation of efficacies at cervical, body and incisal tooth sites.(Nature, 2012) Chan, W.; Lynch, E.; Grootveld, Martin