Venus Flagship Mission Concept: A Decadal Survey Study.

More than any other known planet, Venus is essential to our understanding of the evolution and habitability of Earth-size planets throughout the galaxy. We address two critical questions for planetary science: 1) How, if at all, did Venus evolve through a habitable phase? 2) What circumstances affect how volatiles shape habitable worlds? Volatile elements have a strong influence on the evolutionary paths of rocky bodies and are critical to understanding solar system evolution. It is clear that Venus experienced a different volatile element history from the Earth and provides the only accessible example of one end-state of habitable Earth-size planets.

Longitudinal correlation of 3D OCT to detect early stage erosion in bovine enamel.

Erosive tissue-loss in dental enamel is of significant clinical concern because the net loss of enamel is irreversible, however, initial erosion is reversible. Micro-hardness testing is a standard method for measuring initial erosion, but its invasive nature has led to the investigation of alternative measurement techniques. Optical coherence tomography (OCT) is an attractive alternative because of its ability to non-invasively image three-dimensional volumes.

Inhibitory Effects of Zinc Ions on Enamel Demineralisation Kinetics in vitro.

Metal ions including zinc have the ability to influence enamel demineralisation. However, there is a paucity of data regarding reductions in demineralisation effected by zinc ions (Zn2+) in the literature. Therefore the aim was to measure the effects of zinc ion concentration ([Zn2+]) on the real-time in vitro demineralisation of enamel, during exposure to caries-simulating conditions, using scanning microradiography (SMR).

Effect of Lesion Baseline Severity and Mineral Distribution on Remineralization and Progression of Human and Bovine Dentin Caries Lesions.

The aims of this laboratory study were to compare the effects of lesion baseline severity, mineral distribution and substrate on remineralization and progression of caries lesions created in root dentin. Lesions were formed in dentin specimens prepared from human and bovine dentin using three protocols, each utilizing three demineralization periods to create lesions of different mineral distributions (subsurface, moderate softening, extreme softening) and severity within each lesion type. Lesions were then either remineralized or demineralized further and analyzed using transverse microradiography.

Diet and the microbial aetiology of dental caries: new paradigms.

The microbial and dietary factors that drive caries have been studied scientifically for 120 years. Frequent and/or excessive sugar (especially sucrose) consumption has been ascribed a central role in caries causation, while Streptococcus mutans appeared to play the key role in metabolising sucrose to produce lactic acid, which can demineralise enamel. Many authors described caries as a transmissible infectious disease.

Important considerations in the development of toothpaste formulations for children.

A number of factors should be taken into account when designing toothpaste formulations for use by children at the different stages of their development. While adult toothpaste formulations may provide caries prevention benefits for children at risk of caries, these formulations may also contain higher levels of abrasive in order to address the staining needs of the adult population owing to smoking and the consumption of dietary chromogens such as coffee and tea, which are not normally found in the diet of children. While toothpastes formulated for adults are also likely to contain higher concentrations of surfactant and flavour, many children prefer toothpastes with mild flavours and modest foaming characteristics.

The primary and mixed dentition, post-eruptive enamel maturation and dental caries: a review.

The mouth is in flux from the time the primary teeth begin to erupt, in the first year of life, through to the end of the 'mixed dentition' (i.e. the concurrent eruption of the permanent teeth and exfoliation of the primary teeth), at around 12 years of age.

Effects of fluoride concentration on enamel demineralization kinetics in vitro.

Objectives: The aim of the present study was to measure the effects of fluoride concentration on the real-time in vitro demineralization of enamel during exposure to caries-simulating conditions using Scanning Microradiography (SMR).

Methods: Enamel blocks obtained from non-carious human molars were fixed in SMR environmental cells, through which acidic solutions (0.1M acetic acid, pH 4.

Role of gallium and silver from phosphate-based glasses on in vitro dual species oral biofilm models of Porphyromonas gingivalis and Streptococcus gordonii.

Phosphate-based glasses (PBGs) are excellent controlled delivery agents for antibacterial ions such as silver and gallium. The aim of this study was to assess the potential utility of novel PBGs combining both gallium and silver for use in periodontal therapy. To this end, an in vitro biofilm model with the putative periodontal pathogen, Porphyromonas gingivalis, and an initial colonizer, Streptococcus gordonii, was established.

Benefits of a silica-based fluoride toothpaste containing o-cymen-5-ol, zinc chloride and sodium fluoride.

Fluoride toothpastes in conjunction with tooth brushing are used to clean teeth, control plaque build-up and for anti-caries benefits. Toothpastes are designed with attractive flavours and appearances to encourage regular prolonged use to maximise these benefits. The incorporation of additional ingredients into toothpaste is a convenient way to provide supplementary protection that fits into people's everyday oral care routine.

Protection against enamel demineralisation using toothpastes containing o-cymen-5-ol, zinc chloride and sodium fluoride.

Aim: To evaluate the ability of two experimental toothpastes containing 0.1%w/w o-cymen-5-ol, 0.6%w/w ZnCl2 and 0.

Zinc in the mouth, its interactions with dental enamel and possible effects on caries; a review of the literature.

Zinc is an essential trace element. In the mouth, it is present naturally in plaque, saliva and enamel. Zinc is formulated into oral health products to control plaque, reduce malodour and inhibit calculus formation.

Terahertz pulsed imaging study to assess remineralization of artificial caries lesions.

We compare terahertz-pulsed imaging (TPI) with transverse microradiography (TMR) and microindentation to measure remineralization of artificial caries lesions. Lesions are formed in bovine enamel using a solution of 0.1 M lactic acid/0.

Laboratory assessment of the anticaries potential of a new dentifrice.

Objective: The aim of the present study was to investigate the anticaries potential of a new sodium fluoride dentifrice in comparison to two commercial dentifrices containing different fluoride compounds by determining enamel fluoride uptake (EFU) and early caries lesion remineralization (REM) in an established in vitro caries remineralization/demineralization pH cycling model.

Methods: Test products were: new dentifrice formulation in a fluoride dose-response (0; 675; 1426 ppm F as sodium fluoride [NaF-0; NaF-675; NaF]); Elmex Kariesschutz (1400 ppm F as amine fluoride [AmF]); and Oral-B Pro-Expert (1450 ppm F-1100 ppm F as stannous fluoride and 350 ppm F as sodium fluoride [SnNaF]). Artificial caries-like lesions were formed in human enamel specimens by immersion in lactic acid buffer (LA).

A comparison of terahertz pulsed imaging with transmission microradiography for depth measurement of enamel demineralisation in vitro.

Terahertz pulsed imaging (TPI) is a relatively new, non-ionising and non-destructive imaging technique for studying hard tissues which does not require tooth section preparation, unlike transmission microradiography (TMR). If TPI can measure the depths of caries/demineralisation lesions accurately the same tooth samples could be reused and remeasured during in vitro and in situ studies on de- and/or re-mineralisation. The aim of this study was to compare TPI and TMR for measuring the depths of a range of artificially induced bovine enamel demineralised lesions in vitro.

Decay of photoacoustic signals from biological tissue irradiated by near infrared laser pulses.

We describe the phenomenon of a sudden decrease in the amplitude of photoacoustic signals arising from nanosecond laser pulse irradiation of biological samples, measured in vitro. Several dental enamel and chicken/turkey breast samples are examined. Moderate optical energy densities (i.