Review of nanomaterials in dentistry: interactions with the oral microenvironment, clinical applications, hazards, and benefits.

Interest in the use of engineered nanomaterials (ENMs) as either nanomedicines or dental materials/devices in clinical dentistry is growing. This review aims to detail the ultrafine structure, chemical composition, and reactivity of dental tissues in the context of interactions with ENMs, including the saliva, pellicle layer, and oral biofilm; then describes the applications of ENMs in dentistry in context with beneficial clinical outcomes versus potential risks. The flow rate and quality of saliva are likely to influence the behavior of ENMs in the oral cavity, but how the protein corona formed on the ENMs will alter bioavailability, or interact with the structure and proteins of the pellicle layer, as well as microbes in the biofilm, remains unclear. The tooth enamel is a dense crystalline structure that is likely to act as a barrier to ENM penetration, but underlying dentinal tubules are not. Consequently, ENMs may be used to strengthen dentine or regenerate pulp tissue. ENMs have dental applications as antibacterials for infection control, as nanofillers to improve the mechanical and bioactive properties of restoration materials, and as novel coatings on dental implants. Dentifrices and some related personal care products are already available for oral health applications. Overall, the clinical benefits generally outweigh the hazards of using ENMs in the oral cavity, and the latter should not prevent the responsible innovation of nanotechnology in dentistry. However, the clinical safety regulations for dental materials have not been specifically updated for ENMs, and some guidance on occupational health for practitioners is also needed. Knowledge gaps for future research include the formation of protein corona in the oral cavity, ENM diffusion through clinically relevant biofilms, and mechanistic investigations on how ENMs strengthen the tooth structure

A randomised clinical study to determine the effect of a toothpaste containing enzymes and proteins on plaque oral microbiome ecology

The numerous species that make up the oral microbiome are now understood to play a key role in establishment and maintenance of oral health. The ability to taxonomically identify community members at the species level is important to elucidating its diversity and association to health and disease. We report the overall ecological effects of using a toothpaste containing enzymes and proteins compared to a control toothpaste on the plaque microbiome. The results reported here demonstrate that a toothpaste containing enzymes and proteins can augment natural salivary defences to promote an overall community shift resulting in an increase in bacteria associated with gum health and a concomitant decrease in those associated with periodontal disease. Statistical analysis shows significant increases in 12 taxa associated with gum health including Neisseria spp. and a significant decrease in 10 taxa associated with periodontal disease including Treponema spp. The results demonstrate that a toothpaste containing enzymes and proteins can significantly shift the ecology of the oral microbiome (at species level) resulting in a community with a stronger association to health

La Station de séries Temporelles (SPOT) de l'Océan Pacifique Sud : un premier aperçu sur la communauté des diazotrophes

International audienceThe SPOT station (168°E-20°S,-4500 m) is a recent deep-sea and multidisciplinary marine research observation station whose objective is to establish the first long-time series of basic parameters in the South West Pacific. The primary studies concern the biodiversity, the productivity of key Plankton Functional Types, the biogeochemistry of carbon and nitrogen cycles, and their impact on the reef and coastal ecosystems' productivity. SPOT station is based on the same philosophy of long-lasting observation as HOT (Hawaii Ocean Time-series). The data will be used to describe and understand the seasonal and long-term variations of the SouthWest Pacific ecosystem related to ENSO (El Niño Southern Oscillation)

La Station de séries Temporelles (SPOT) de l'Océan Pacifique Sud : un premier aperçu sur la communauté des diazotrophes

International audienceThe SPOT station (168°E-20°S,-4500 m) is a recent deep-sea and multidisciplinary marine research observation station whose objective is to establish the first long-time series of basic parameters in the South West Pacific. The primary studies concern the biodiversity, the productivity of key Plankton Functional Types, the biogeochemistry of carbon and nitrogen cycles, and their impact on the reef and coastal ecosystems' productivity. SPOT station is based on the same philosophy of long-lasting observation as HOT (Hawaii Ocean Time-series). The data will be used to describe and understand the seasonal and long-term variations of the SouthWest Pacific ecosystem related to ENSO (El Niño Southern Oscillation)

La Station de séries Temporelles (SPOT) de l'Océan Pacifique Sud : un premier aperçu sur la communauté des diazotrophes

International audienceThe SPOT station (168°E-20°S,-4500 m) is a recent deep-sea and multidisciplinary marine research observation station whose objective is to establish the first long-time series of basic parameters in the South West Pacific. The primary studies concern the biodiversity, the productivity of key Plankton Functional Types, the biogeochemistry of carbon and nitrogen cycles, and their impact on the reef and coastal ecosystems' productivity. SPOT station is based on the same philosophy of long-lasting observation as HOT (Hawaii Ocean Time-series). The data will be used to describe and understand the seasonal and long-term variations of the SouthWest Pacific ecosystem related to ENSO (El Niño Southern Oscillation)