Factors affecting the number of bacteria in saliva and oral care methods for the recovery of bacteria in contaminated saliva after brushing: a randomized controlled trial

BACKGROUND

Oral care is important in preventing aspiration pneumonia in older adults. However, it is not clear what kind of oral care can reduce the number of bacteria in saliva. The purposes of this study are to clarify whether there is a relationship between plaque amounts and salivary bacterial counts, and how bacteria dispersed into the oral cavity by brushing can be reduced.

METHODS

First, saliva samples were collected from 10 healthy adult volunteers after 30 h of unbrushing and after thorough brushing, and the total bacterial count was determined by real-time PCR. Next, 40 older adults attending an outpatient dental clinic were randomly assigned into two groups: a wiping group (20 patients) and a mouthwashing group (20 patients). Saliva was collected before and after brushing, and after wiping in the wiping group and after mouthwashing in the mouthwashing group, and the total bacterial count was quantified by real-time PCR.

RESULTS

In a study of volunteers, there was no association between plaque amounts and salivary bacterial counts. In a study of older adult patients, salivary bacterial counts were significantly higher in patients with higher oral hygiene index and fewer remaining teeth. Brushing increased salivary bacterial counts. Wiping did not significantly reduce the number of bacteria, while mouthwash returned the increased number of bacteria after brushing to the pre-brushing level.

CONCLUSIONS

There is no direct relationship between the amount of plaque and the number of bacteria in saliva. Brushing disperses bacteria into the oral cavity, resulting in a marked increase in the number of bacteria in saliva. Wiping does not collect the dispersed bacteria, and it seems essential to rinse the mouth after brushing.

TRIAL REGISTRATION

UMIN000045854.

Relationship between Tongue Pressure and Salivary Bacteria in the Older Adults Requiring Long-Term Care

INTRODUCTION

Aspiration pneumonia, an important issue for the older adults, is caused by an increase in pathogenic microorganisms in the saliva, aspiration, and weakened host immunity. Recently, decreased tongue pressure has been reported to be associated with dysphagia. This study aimed to investigate the relationship between decreased tongue pressure and the number of bacteria in the saliva of the older adults requiring long-term care.

METHODS

This cross-sectional study involved 95 older adults requiring long-term care in a facility or at home, eating orally, and who could understand the instructions for measuring tongue pressure. Sex, age, slowness, weakness, shrinking, exhaustion, low activity, number of teeth, functional teeth unit, denture use, oral hygiene, tongue coating index, dry mouth, tongue pressure, and number of bacteria in the saliva were examined. Bacterial counts were analyzed by real-time PCR for total bacteria, total streptococci, methicillin-resistant Staphylococcus aureus, Streptococcus pneumoniae, Pseudomonas aeruginosa, Porphyromonas gingivalis, and Candida albicans.

RESULTS

Multiple regression analysis showed that poor oral hygiene and decreased tongue pressure were independent risk factors for increased bacteria in the saliva. Decreased tongue pressure is significantly correlated with an increased number of total bacteria and the presence of P. gingivalis.

DISCUSSION/CONCLUSION

Our results suggest that tongue pressure not only maintains the swallowing function but also prevents the increase of bacteria in the saliva of older adults requiring long-term care.

Dental needs in palliative care and problems in dental hygienist education: survey study of palliative care ward homepage, university syllabus, and academic conference abstracts

Background

Although end-of-life patients have a variety of oral-related symptoms, the involvement of dentists and dental hygienists in the palliative care teams is limited. This study investigates the current state of palliative care education in universities that train dentists and dental hygienists and the need for dentistry in the clinical setting of palliative medicine in Japan.

Methods

First, we investigated the involvement of dentistry in hospitals with palliative care units from a website. The number of reports on palliative care presented by dental hygienists at academic conferences around 2016, when the public medical insurance system in Japan covered oral care for patients with terminal illnesses, were examined. We also surveyed the syllabuses of the university that trained nurses, dentists, and dental hygienists to determine their education regarding palliative care.

Results

Of the 376 hospitals with palliative care units, 176 (46.8%) had dentistry in the hospital. Additionally, 321 hospitals (85.4%), which included those without dentistry, responded that they provided oral care by dentists and dental hygienists in the palliative care unit. There were only two presentations on palliative care in the annual meetings of the two major academic societies by dental hygienists between 2012 and 2016. However, this number increased rapidly to 47 between 2017 and 2020. The syllabus surveys showed that, compared to nursing universities, universities that trained dentists or dental hygienists had lesser education in palliative care. Furthermore, education in the universities that trained dental hygienists was mostly related to the oral care of patients with terminal illnesses, while the physical and mental conditions of end-of-life patients were not well educated.

Conclusion

Considering that society requires the involvement of dental hygienists in the field of palliative care, it is necessary to enhance basic and clinical education of palliative care in universities that train dentists and dental hygienists to provide good oral care to patients with terminal illnesses and contribute to improving their quality of life.

Geranylgeraniol Induces PPARγ Expression and Enhances the Biological Effects of a PPARγ Agonist in Adipocyte Lineage Cells

BACKGROUND

The global incidence of diabetes mellitus (DM) has risen precipitously, even in middle- and low-income countries. Peroxisome proliferator-activated receptor γ (PPARγ) plays an important role in the control of cellular glucose metabolism. Activation of PPARγ beneficially results in increased insulin sensitivity. However, the expression of PPARγ is reduced by obesity and several nutritional factors. Here we examined the effect of geranylgeraniol (GGOH), a bioactive compound found naturally in fruits, vegetables, and grains, on the expression and activation of PPARγ.

MATERIALS AND METHODS

C3H10T1/2 mouse embryonic fibroblasts and 3T3-L1 pre-adipocytes were used as in vitro models of adipocyte differentiation and function. Quantitative reverse-transcriptase polymerase chain reaction, western blotting, Oil Red O staining, and luciferase assay were performed to respectively assess mRNA expression, protein levels, lipid droplet formation and transcriptional activity.

RESULTS

GGOH increased the expression of PPARγ in adipocyte lineage cells. GGOH also enhanced adipogenesis induced by rosiglitazone, a thiazolidinedione class PPARγ agonist.

CONCLUSION

GGOH induces PPARγ expression and enhances the biological effects of a PPARγ agonist in adipocyte lineage cells.

Geranylgeraniol-induced Myogenic Differentiation of C2C12 Cells

BACKGROUND

Geranylgeraniol (GGOH) is a C20 isoprenoid found in fruits, vegetables, and grains, including rice. As a food substance, GGOH is categorized as 'Generally Recognized as Safe'. GGOH is an intermediate product in the mevalonate pathway and acts as a precursor to geranylgeranyl pyrophosphate.

MATERIALS AND METHODS

C2C12 mouse myoblasts derived from muscle satellite cells were used. Quantitative reverse-transcriptase polymerase chain reaction, western blotting analysis, and immunocytochemical analysis were performed to respectively assess mRNA expression, protein levels, and the number of myofibers.

RESULTS

GGOH reduced the expression levels of skeletal muscle atrophy-related ubiquitin ligases in myofibers derived from C2C12 cells. GGOH induced myogenic differentiation of C2C12 cells via geranylgeranylation. GGOH did not adversely affect the proliferation of C2C12 cells.

CONCLUSION

GGOH induces myoblast differentiation in C2C12 cells.

Validity and reliability of the oral health-related caregiver burden index

OBJECTIVE

This study developed the Oral Health-related Caregiver Burden Index (OHBI), which contains nine questions with five response options each. As a secondary objective, we aimed to clarify the relationship between oral health-related caregiver burden and general caregiver burden.

BACKGROUND

There are a few reports of the oral health-related caregiver burden.

METHODS

Between January 2016 and February 2016, 155 participants enrolled in the study. We conducted the survey to examine the validity and reliability of OHBI. Additionally, the cut-off score for this scale was calculated, and the relationship between OHBI and general caregiver burden (BIC-11) was examined by binomial logistic regression.

RESULTS

Survey 1 was completed by 102 caregivers, of whom 58 (56.9%) were female. Survey 2 was completed by 40 caregivers, of whom 22 (55.0%) were female. Factor analysis revealed four factors in OHBI. Cronbach's α was .691-.866. OHBI scores were significantly associated with scores for each factor of the BIC-11. OHBI had a cut-off score of 10 (AUC=.881, sensitivity=.828, specificity=.744). A good-poor analysis revealed significant differences for discriminant validity. ICC, an indicator of reliability, was .449-.842. There was a significant relationship between caregiver burden and oral health-related caregiver burden according to binomial logistic regression analysis (P<.05).

CONCLUSION

We developed the OHBI as a multidimensional care burden scale, which comprises nine items covering five domains. Further, we verified the relationship between general caregiver burden and oral health-related caregiver burden.

Domino model for geomagnetic field reversals

We solve the equations of motion of a one-dimensional planar Heisenberg (or Vaks-Larkin) model consisting of a system of interacting macrospins aligned along a ring. Each spin has unit length and is described by its angle with respect to the rotational axis. The orientation of the spins can vary in time due to spin-spin interaction and random forcing. We statistically describe the behavior of the sum of all spins for different parameters. The term "domino model" in the title refers to the interaction among the spins. We compare the model results with geomagnetic field reversals and dynamo simulations and find strikingly similar behavior. The aggregate of all spins keeps the same direction for a long time and, once in a while, begins flipping to change the orientation by almost 180 degrees (mimicking a geomagnetic reversal) or to move back to the original direction (mimicking an excursion). Most of the time the spins are aligned or antialigned and deviate only slightly with respect to the rotational axis (mimicking the secular variation of the geomagnetic pole with respect to the geographic pole). Reversals are fast compared to the times in between and they occur at random times, both in the model and in the case of the Earth's magnetic field.