Prospects for the development of probiotics and prebiotics for oral applications

There has been a paradigm shift towards an ecological and microbial community-based approach to understanding oral diseases. This has significant implications for approaches to therapy and has raised the possibility of developing novel strategies through manipulation of the resident oral microbiota and modulation of host immune responses. The increased popularity of using probiotic bacteria and/or prebiotic supplements to improve gastrointestinal health has prompted interest in the utility of this approach for oral applications. Evidence now suggests that probiotics may function not only by direct inhibition of, or enhanced competition with, pathogenic micro-organisms, but also by more subtle mechanisms including modulation of the mucosal immune system. Similarly, prebiotics could promote the growth of beneficial micro-organisms that comprise part of the resident microbiota. The evidence for the use of pro or prebiotics for the prevention of caries or periodontal diseases is reviewed, and issues that could arise from their use, as well as questions that still need to be answered, are raised. A complete understanding of the broad ecological changes induced in the mouth by probiotics or prebiotics will be essential to assess their long-term consequences for oral health and disease

Possible monoclinic distortion of Mo2GaC under high pressure

In this work, we present high-pressure diffraction results of the Mo-based M-n (+) (1)AX(n) phase, Mo2GaC. A diamond anvil cell was used to compress the material up to 30 GPa, and x-ray diffraction was used to determine the structure and unit cell parameters as a function of pressure. Somewhat surprisingly, we find that, at 295 +/- 25 GPa, the bulk modulus of Mo2GaC is the highest reported of all the MAX phases measured to date. The c/a ratio increases with increasing pressure. At above 15 GPa, a splitting in the (1 0 0) reflection occurs. This result, coupled with new density functional theory calculations, suggests that a second order phase transition to possibly a mixture of hexagonal and monoclinic structures may explain this splitting. Such experimentally and theoretically supported phase transitions were not predicted in previously published calculations.Funding Agencies|Knut and Alice Wallenberg (KAW) FoundationKnut &amp; Alice Wallenberg Foundation; Swedish Research CouncilSwedish Research Council [642-2013-8020]; National Science Foundation (NSF)National Science Foundation (NSF) [DMR-1729335]</p

Halitosis management by the general dental practitioner--results of an international consensus workshop

Clinical investigations on patients suffering from halitosis clearly reveal that in the vast majority of cases the source for an offensive breath odor can be found within the oral cavity (90%). Based on these studies, the main sources for intra-oral halitosis where tongue coating, gingivitis/periodontitis or a combination of the two. Thus, it is perfectly logical that general dental practitioners (GDPs) should be able to manage intra-oral halitosis under the conditions found in a normal dental practice. However, GDPs who are interested in diagnosing and treating halitosis are challenged to incorporate scientifically based strategies for use in their clinics. Therefore, the present paper summarizes the results of a consensus workshop of international authorities held with the aim to reach a consensus on general guidelines on how to assess and diagnose patients' breath odor concerns and general guidelines on regimens for the treatment of halitosis.status: publishe