The Oral Microbiome and Cross-Kingdom Interactions during Pregnancy

Pregnancy initiates a temporary transition in the maternal physiological state, with a shift in the oral microbiome and a potential increase in frequency of oral diseases. The risk of oral disease is higher among populations of Hispanic and Black women and those with lower socioeconomic status (low SES), demonstrating a need for intervention within these high-risk populations. To further our understanding of the oral microbiome of high-risk pregnant women, we characterized the oral microbiome in 28 nonpregnant and 179 pregnant low-SES women during their third trimester living in Rochester, New York. Unstimulated saliva and supragingival plaque samples were collected cross-sectionally, followed by assessment of the bacterial (16S ribosomal RNA) and fungal (18S ITS) microbiota communities. Trained and calibrated dentists performed oral examinations to determine the number of decayed teeth and plaque index. Initially, plaque from 28 nonpregnant women and 48 pregnant women were compared; these data showed significant differences in bacterial abundances based on pregnancy status. To further our understanding of the oral microbiome within the pregnant population, we next examined the oral microbiome within this population based on several variables. Streptococcus mutans, Streptococcus oralis, and Lactobacillus were associated with a greater number of decayed teeth. The composition of fungal communities differed between plaque and saliva, demonstrating 2 distinct "mycotypes" that were represented by a greater abundance of Candida in plaque and Malassezia in saliva. Veillonella rogosae, a common oral bacterium, was negatively associated with both plaque index and salivary Candida albicans colonization by culture data. This was further emphasized by in vitro inhibition of C. albicans by V. rogosae. Identification of interactions between the bacterial or fungal oral communities revealed that V. rogosae was positively associated with the oral commensal Streptococcus australis and negatively with the cariogenic Lactobacillus genus, suggesting V. rogosae as a potential biomarker of a noncariogenic oral microbiome.

Reorienting Oral Health Services to Prevention: Economic Perspectives

Despite the recognized need to change the emphasis of health services by shifting the balance from treatment to prevention, limited progress has been made in many settings. This is true in oral health, where evidence for preventive interventions that work has not been systematically exploited in oral health services. While reorienting health services is complex and context specific, economics can bring a helpful perspective in understanding and predicting the impact of changes in resource allocation, provider remuneration systems, and patient payments. There is an increasing literature on the economics of different prevention approaches. However, much of this literature focuses on the costs and potential savings of alternative approaches and fails to take into account benefits. Even where benefits are taken into account, these tend to be narrowly focused on clinical outcomes using cost-effectiveness analysis, which may be of little relevance to the policy maker, patient, and the public. Some commonly used economic approaches (such as quality-adjusted life years and incremental cost-effectiveness ratios) may also not be appropriate to oral health. Using alternative techniques, including wider measures of benefit and employing priority setting and resource allocation tools, may provide more comprehensive information on economic impact to decision makers and stakeholders. In addition, it is important to consider the effects of provider remuneration in reorienting services. While there is some evidence about traditional models of remuneration (fee for service and capitation), less is known about pay for performance and blended systems. This article outlines areas in which economics can offer an insight into reorientation of health systems toward prevention, highlighting areas for further research and consideration.

Attempt to assess the infiltration of enamel made with experimental preparation using a scanning electron microscope

INTRODUCTION

The resin infiltration technique, a minimally invasive method, involves the saturation, strengthening, and stabilization of demineralized enamel by a mixture of polymer resins without the need to use rotary tools or the risk of losing healthy tooth structures.

AIM OF THE STUDY

To design and synthesize an experimental infiltrant with potential bacteriostatic properties.To compare the depth of infiltration of the designed experimental preparation with the infiltrant available in the market using a scanning electron microscope.

MATERIAL AND METHODS

Composition of the experimental infiltrant was established after analysis of 1H NMR spectra of the commercially available compounds that can penetrate pores of demineralized enamel. As the infiltrant should have bacteriostatic features by definition, an addition of 1% of monomer containing metronidazole was made. Thirty extracted human teeth were soaked in an acidic solution, which was to provide appropriate conditions for demineralization of enamel. Afterward, each tooth was divided along the coronal-root axis into two zones. One zone had experimental preparation applied to it (the test group), while the other had commercially available Icon (the control group). The teeth were dissected along the long axis and described above underwent initial observation with use of a Hitachi S-4200 scanning electron microscope.

RESULTS

It was found that all samples contained only oxygen and carbon, regardless of the concentration of additions introduced into them. The occurrence of carbon is partially because it is a component of the preparation in question and partially because of sputtering of the sample with it. Hydrogen is also a component of the preparation, as a result of its phase composition; however, it cannot be detected by the EDS method.

CONCLUSIONS

SEM, in combination with X-ray microanalysis, does not allow one to explicitly assess the depth of penetration of infiltration preparations into enamel.In order to assess the depth of penetration of infiltration preparations with use of X-ray microanalysis, it is recommended to introduce a contrast agent that is approved for use in dental materials, such as ytterbium III fluoride.