Inflation of 430-parsec bipolar radio bubbles in the Galactic Centre by an energetic event.

The Galactic Centre contains a supermassive black hole with a mass of four million Suns1 within an environment that differs markedly from that of the Galactic disk. Although the black hole is essentially quiescent in the broader context of active galactic nuclei, X-ray observations have provided evidence for energetic outbursts from its surroundings2. Also, although the levels of star formation in the Galactic Centre have been approximately constant over the past few hundred million years, there is evidence of increased short-duration bursts3, strongly influenced by the interaction of the black hole with the enhanced gas density present within the ring-like central molecular zone4 at Galactic longitude |l| < 0.7 degrees and latitude |b| < 0.2 degrees. The inner 200-parsec region is characterized by large amounts of warm molecular gas5, a high cosmic-ray ionization rate6, unusual gas chemistry, enhanced synchrotron emission7,8, and a multitude of radio-emitting magnetized filaments9, the origin of which has not been established. Here we report radio imaging that reveals a bipolar bubble structure, with an overall span of 1 degree by 3 degrees (140 parsecs × 430 parsecs), extending above and below the Galactic plane and apparently associated with the Galactic Centre. The structure is edge-brightened and bounded, with symmetry implying creation by an energetic event in the Galactic Centre. We estimate the age of the bubbles to be a few million years, with a total energy of 7 × 1052 ergs. We postulate that the progenitor event was a major contributor to the increased cosmic-ray density in the Galactic Centre, and is in turn the principal source of the relativistic particles required to power the synchrotron emission of the radio filaments within and in the vicinity of the bubble cavities.

Public health issues in geriatric dentistry in the United States.

The aging United States population living in the new millennium has dental needs that are very different and more complex than those experienced by previous older adult cohorts during the twentieth century. The type of dental care to be provided for older Americans goes way beyond emergency care, extractions and denture care. Dental caries is still clearly a public health problem for subgroups of older Americans, such as those of lower socioeconomic status, with dementia, who are homebound and who are institutionalized. These are also the subgroups experiencing greater barriers to accessing dental care. Stakeholders, including dental professionals and the dental benefits industry, need to work together to develop innovative dental financing programs that will increase older Americans access to dental care.

The oral health assessment tool--validity and reliability.

BACKGROUND: The Oral Health Assessment Tool (OHAT) was a component of the Best Practice Oral Health Model for Australian Residential Care study. The OHAT provided institutional carers with a simple, eight category screening tool to assess residents' oral health, including those with dementia. This analysis presents OHAT reliability and validity results. METHODS: A convenience sample of 21 residential care facilities (RCFs) in urban and rural Victoria, NSW and South Australia used the OHAT at baseline, three-months and six-months to assess intra- and inter-carer reliability and concurrent validity. RESULTS: Four hundred and fifty five residents completed all study phases. Intra-carer reliability for OHAT categories: percent agreement ranged from 74.4 per cent for oral cleanliness, to 93.9 per cent for dental pain; Kappa statistics were in moderate range (0.51-0.60) for lips, saliva, oral cleanliness, and for all other categories in range of 0.61-0.80 (substantial agreement) (p < 0.05). Inter-carer reliability for OHAT categories: percent agreement ranged from 72.6 per cent for oral cleanliness to 92.6 per cent for dental pain; Kappa statistics were in moderate range (0.48-0.60) for lips, tongue, gums, saliva, oral cleanliness, and for all other categories in range of 0.61-0.80 (substantial agreement) (p < 0.05). Intraclass correlation coefficients for OHAT total scores were 0.78 for intra-carer and 0.74 for inter-carer reliability. Validity analyses of the OHAT categories and examination findings showed complete agreement for the lips category, with the natural teeth, dentures, and tongue categories having high significant correlations and percent agreements. The gums category had significant moderate correlation and percent agreement. Non-significant and low correlations and percent agreements were evident for the saliva, oral cleanliness and dental pain categories. CONCLUSION: The Oral Health Assessment Tool was evaluated as being a reliable and valid screening assessment tool for use in residential care facilities, including those with cognitively impaired residents.

The practical oral care video--evaluation of a dental awareness month initiative.

BACKGROUND: A collaborative effort for the Australian Dental Association's Dental Awareness Month in 2002 included the production of 'Practical Oral Care - a video for residential care staff'. This evaluation of the project aimed to profile the video purchasers, evaluate the usefulness and appropriateness of the video and accompanying booklet using a mailed questionnaire, and elicit appropriate and practical themes for future geriatric oral health promotion and research. METHODS: A national mail-out of evaluation questionnaires was undertaken to all purchasers of the video. RESULTS: Of the 792 purchasers at the time of the project, 294 questionnaires were returned with 83.7 per cent from residential aged care facilities, 12.6 per cent from dental professionals and 3.7 per cent from health educators. The great majority of purchasers agreed or strongly agreed that the booklet was practical and useful, video was the best format, video length was appropriate, content was realistic, the video assisted staff to identify residents at risk for dental problems and better meet their oral care needs, and improved awareness about oral care issues. Analysis of purchasers' comments highlighted the need for the production of videos on more specific practical oral care issues with behaviourally difficult residents and residents with dementia, to be supplemented with a self-directed learning package. CONCLUSIONS: The Practical Oral Care video was a successful national collaborative geriatric oral health promotion initiative and provided the opportunity to increase awareness about oral care issues in residential care.

Oral health promotion for our ageing Australian population.

The ageing Australian population living in the new millennium has dental needs that are very different and more complex than those experienced by previous older adult cohorts during the twentieth century. A summary of the oral health status of older Australians is presented, together with a review of the important relationships between general health and oral health. The key to maintaining and improving older adults' oral health status is the use of oral health promotion strategies that focus not only on dental characteristics, but also on the life characteristics of older adults, and on their quality of life issues. Traditionally, there has been very limited geriatric oral health promotion, with several myths contributing to this situation. Contemporary geriatric oral health promotion in the new millenium has an evidence-based and planned approach. It encompasses not only the treatment of oral diseases and conditions, but has an increased focus on the prevention of oral diseases and conditions to enhance oral health status and older adults' quality of life. Using the Ottawa Charter and a functional dependence classification, a geriatric oral health promotion matrix is presented, using a specific example of Australian residential care.

Analysis of thin film coatings on poly(ethylene terephthalate) by confocal Raman microscopy and surface-enhanced Raman scattering.

The characterization of thin coatings on polymers such as poly(ethylene terephthalate) (PET) is required in order to study chemical composition and coating continuity. Two different methods of applying Raman spectroscopy for this purpose are compared in this paper. Using confocal Raman microscopy, thick coatings (> 10 microns) are relatively easily identified; however, the Raman scattering from the acrylic coatings commonly used is much weaker than that of PET and consequently, there is a background due to the substrate. Thin acrylic coatings (< 1 micron) usually cannot be detected. Surface-enhanced Raman scattering (SERS) of uncoated PET gives intense signals and if the spectra are taken from the metal-coated side, there is no evidence of the underlying Raman scattering from the bulk. Acrylic coatings do not give sufficiently strong or reproducible SERS to be reliably identified, but even thin (20 nm) coatings completely block the SERS from the substrate. Only where gaps appear in the coating is the SERS of the underlying PET seen. To detect a positive signal from the coating, SERS active labels were incorporated into the acrylic at low concentrations either as a physical mixture or as reactive co-monomers. This uniquely labels the coating and allows detection and, in principle, mapping of the coverage. Thus, for thick (> > 1 micron) coatings, normal Raman spectroscopy is an effective technique for detecting the presence of the surface coating. However, it is ineffective with thin (< 1 micron) coatings, and SERS alone only indicates where the coating is incomplete or defective. However, when a SERS label is added, spectra can be detected from very thin coatings (20 nm). The concentration of the labels is sufficiently low for the coating to remain colorless.

The prevalence and experience of oral diseases in Adelaide nursing home residents.

BACKGROUND: The twenty-first century will see the evolution of a population of dentate older Australians with dental needs very different from those of older adults in past years. This study provided comprehensive information concerning oral disease prevalence in older South Australian nursing home residents. METHODS: This paper presents cross-sectional baseline results. RESULTS: Most of the 224 residents, from seven randomly selected nursing homes, were functionally dependent, medically compromised, cognitively impaired and behaviourally difficult older adults who presented many complex challenges to carers and to dental professionals. Two-thirds (66 per cent) were edentulous with many dental problems and treatment needs. Dentate residents had a mean of 11.9 teeth present, higher than previously reported. The prevalence and experience of coronal and root caries and plaque accumulation was very high in dentate residents; especially males, those admitted more than three years previously, those who ate fewer food types and those who were severely cognitively impaired. These residents had more retained roots, decayed teeth and missing teeth, and fewer filled teeth when compared with data for community-dwelling older adults. CONCLUSIONS: This study highlighted the poor oral health status of these nursing home residents and the great impact of dementia on their high levels of oral diseases.

Caries incidence and increments in community-living older adults with and without dementia.

OBJECTIVES: The Oral Health of Older Adults with Dementia was instigated in the late 1990s to quantify and compare coronal and root caries incidence and increments in community-living older Australians with and without dementia. METHODS: A longitudinal design was used to conduct dental inspections at baseline and one-year, for two groups of randomly selected community-living older adults--one group of 116 people with dementia and a comparison group of 116 people without dementia. RESULTS: At one-year there were 103 dementia and 113 (112 dentate) non-dementia participants. Coronal and root surface caries incidence was higher for dementia participants (p < 0.05). Dementia participants had higher coronal and root caries adjusted caries increments (ADJCI) (p < 0.01). Both coronal and root ADJCI were evident in half of dementia participants, compared with one-quarter of non-dementia participants. Dementia participants with higher coronal ADJCI were those who had visited the dentist since baseline, who were taking neuroleptics with high anticholinergic adverse effects, and whose carer had high carer burden score (p < 0.01). Dementia participants with higher root ADJCI were those needing assistance with oral hygiene care and whose carers had difficulties with oral hygiene care (p < 0.05). Baseline characteristics predictive in linear regression for: (1) coronal caries increments among all participants were--dementia participants, those with cognitive testing scores indicative of moderate-severe dementia, those with private health insurance; (2) root caries increments among all participants were--dementia participants, and those who had > or = 1 decayed/filled root surface at baseline. Among dementia participants, being male was the baseline characteristic predictive in logistic regression for coronal caries increments, and having > or = 1 decayed coronal surface was the baseline characteristic predictive for root caries increments. CONCLUSIONS: Coronal and root caries incidence and increments were significantly higher in the community-living older adults with dementia over the one-year follow-up period. Dementia participants had high levels of coronal and root caries increments; characteristics related to high caries increments included sex (males), dementia severity (moderate-severe), high carer burden, oral hygiene care difficulties, use of neuroleptic medication (with high anticholinergic adverse effects) and previous experience of caries.

Geriatric oral health issues in Australia.

AIM: To identify and discuss geriatric oral health issues in Australia. METHODS: A discussion of the demographic trends, oral health trends, and barriers to dental care for older Australians is presented, together with a review of Australian public and private sector geriatric dental services, geriatric dental research, and geriatric dental education. CONCLUSIONS: Key geriatric oral health issues for Australia include: edentulism is decreasing and older Australians are retaining more natural teeth; coronal and root caries are significant problems, especially as older adults become more functionally dependent, cognitively impaired, and medically compromised; the oral health status of institutionalised older Australians is poor; the onset of severe oral diseases appears to occur in many older Australians prior to their institutionalisation, when they are homebound and dependent upon carers; carers of older adults do not have access to practical education about dental care; the majority of older Australians are eligible to use public-funded dental services, but barriers limit their access to these services; few Australian public or private dental services are designed with a geriatric focus; geriatric dental education does not have a high profile in Australian dental schools; no specialty exists in Australia for geriatric dentistry, nor is there a national geriatric dentistry association.

Opinions of dentists and directors of nursing concerning dental care provision for Adelaide nursing homes.

BACKGROUND: The complex oral health problems of nursing home residents have been well documented. However, the influences on residents' oral health status, including opinions and experiences of dental professionals and nursing home staff, have not yet been adequately investigated. METHODS: The baseline questionnaire component of this longitudinal study was mailed to all registered dentists practising in Adelaide and Adelaide nursing home directors of nursing (DONs). RESULTS: 413 dentists and 97 DONs indicated that Adelaide dentists' interest and training in nursing home dentistry was low. Dental service provision for nursing home residents was very low and dentists preferred to provide treatment at their dental practices. Few dental hygienists were working in nursing homes and dental professionals provided little educational assistance for nursing home staff. Dentists and DONs held several common and many varying perceptions of the problems associated with dental care provision in nursing homes. Both identified a group of nursing home environmental constraints and a lack of portable dental equipment. DONs further identified a group of resident related problems, and dentists a group of dental practice-related problems. CONCLUSIONS: These study results provide important information concerning problems with nursing home dentistry for dental service providers, educators, policy-makers, administrators and nursing home staff.

Medication and dry mouth: findings from a cohort study of older people.

OBJECTIVES: The aim of this study was to examine the association between medication exposure and (1) unstimulated whole-salivary flow rate and (2) the severity of xerostomia among older people while adjusting for multiple medication use. METHODS: Data were obtained from participants remaining at the five-year follow-up phase of a cohort study of community-dwelling older South Australians. Medication exposure information was available at baseline and at five years, enabling examination of the effects on dry mouth of long-term exposure to medications. At the five-year follow-up, unstimulated salivary flow was estimated using the spit method, and xerostomia severity was estimated using the 11-item Xerostomia Inventory. Because of the potential difficulties posed by polypharmacy, a two-stage analytical approach was employed: (1) Classification and Regression Tree (CART) analysis was used as an exploratory device to elucidate the relationships among the dependent and independent variables, and (2) linear regression analysis was used as a complementary procedure. RESULTS: Unstimulated flow rate was lower among individuals who were female or taking antidepressants at both baseline and five years, and higher among smokers or people who were taking hypolipidemic drugs. Xerostomia severity was higher among females, or individuals taking: (1) an anginal at baseline and five years, (2) an anginal without a concomitant betablocker at five years, (3) thyroxine and a diuretic at five years, or (4) antidepressants or antiasthma drugs at both baseline and at five years. CONCLUSIONS: These results suggest that polypharmacy can be accounted for to a certain extent by using CART analysis in conjunction with more conventional approaches; and that the relationship between medications and dry mouth is a complex one, and differs according to which aspect of dry mouth is being examined.

Behavior management and communication strategies for dental professionals when caring for patients with dementia.

The impact of dementia and associated behavioral problems on the oral health of long-term-care-facility residents is increasing. The provision of oral hygiene care for these cognitively impaired residents is difficult and complex. Dental professionals and carers need good communication skills with cognitively impaired residents, and specific strategies for the management and prevention of their behavioral problems. Newer philosophies of dementia care enable dental professionals and carers to use more individualized and non-pharmacological approaches for dental treatment and preventive oral care provision. This paper reviews behavior management and communication strategies from the dental literature, and newer techniques and interventions from dementia research and literature.

Conducting geriatric dental research with cognitively impaired adults.

A growth in research focusing on the oral health of older adults has been evident in recent years. However, there are new and complex challenges for geriatric dental researchers studying the increasingly functionally dependent and cognitively impaired older adult population. Many geriatric dental studies have under-reported oral disease prevalence and incidence by excluding adults who are cognitively impaired and/or behaviourally difficult. To ensure representative samples of older adult populations are studied, traditional oral epidemiological protocols in studies with cognitively impaired adults, require additional components detailing: (1) communication and behaviour management strategies for cognitively impaired adults; and (2) methodologies to facilitate the completion of dental examinations. A description of such additional protocol components is presented, along with a discussion of the use of cognitive testing tools by dental researchers.

The occurrence of xerostomia and salivary gland hypofunction in a population-based sample of older South Australians.

This paper examines the prevalence of and concurrence between the symptoms of dry mouth (xerostomia) and reduced salivary flow (SGH) among a population-based sample of older South Australians. Participants in a longitudinal dental study of older people were asked a global question about their experience of dry mouth ("How often does your mouth feel dry?"), and those who responded "Always" or "Frequently" were categorized as xerostomic. Unstimulated whole salivary flow rate was measured, and individuals whose flow rate was less than 0.1 mL/min were categorized as SGH cases. Saliva samples were collected from 700 individuals, of whom 683 (97.7%) answered the dry-mouth question. The mean unstimulated salivary flow rate was 0.27 mL/min (SD 0.22). The prevalence of SGH was 22.1%, and the prevalence of xerostomia was 20.5%, but only 5.7% of participants had both conditions. Almost two-thirds of the sample had neither condition. Males and females differed in the degree of concurrence between the two conditions. It appears that, in the group studied, xerostomia and SGH were largely discrete conditions, supporting the assertion by other workers that low salivary flow may not be the key factor in the etiology of xerostomia among older people.

The Xerostomia Inventory: a multi-item approach to measuring dry mouth.

OBJECTIVE: To develop a valid multi-item method of measuring the symptoms of xerostomia which includes the wide range of xerostomia symptoms in a single quantitative measure. DESIGN: A combination of qualitative and quantitative approaches. SETTING: A cohort study in South Australia. PARTICIPANTS: Older people aged 65 years or more who were taking part in the South Australian Dental Longitudinal Study. MEASURES: Xerostomia symptoms were evaluated using a multi-item inventory format and, for comparison purposes, a standard single dry-mouth question. Resting whole-salivary flow rate was estimated using the 'spit' method. RESULTS: Xerostomia and flow-rate data were available for 636 individuals. Factor analysis revealed the presence of a discrete xerostomia dimension, represented by 11 items whose responses were summated to give a single Xerostomia Inventory (XI) scale score. This had a very low correlation with resting flow rate but a much stronger, positive correlation with the standard dry-mouth question responses. CONCLUSIONS: The XI shows adequate content and concurrent validity, and appears to be a promising advance on previous approaches to xerostomia symptomatology although further testing is required.

A multidisciplinary dental program for community-living adults with chronic mental illness.

Only recently have reports described specialized large-scale dental programs for community-living adults with chronic mental illness. In response to requests from community mental health center case managers, a multidisciplinary team from Central Sydney Area Health Service dentistry, mental health, and transport services joined together to develop a pilot dental program. The aim was to profile the dental needs of community-living clients with chronic mental illness and to improve clients' utilization of inner Sydney public dental services. A review of clients' dental problems and access is presented, together with a description of the pilot program developed by the multidisciplinary team. A profile of the initial dental needs of the participants, and information on the participants' utilization of the pilot dental program is documented. This multidisciplinary approach was successful in developing a program to profile dental needs of clients, and improved the access to public dental services for the majority of clients. There was a subgroup of clients who did not utilize the program, and further follow-up of these clients is needed. This multidisciplinary approach could be useful in the development and funding of other special care dental programs.

Oral health of persons with and without dementia attending a geriatric clinic.

This study of 230 hospital geriatric clinic patients compared the oral health of individuals with dementias with that of persons with no dementing illnesses. Data collected included dental examinations, subject questionnaires and review of hospital records. There were few differences among groups of patients based on categorization into groups of those diagnosed with (1) no dementia, (2) dementia of the Alzheimer's type, and (3) other dementias. However, there were significant differences based on degree of cognitive impairment regardless of dementia diagnosis. Those with severe dementia had poorer gingival health and oral hygiene, but better self-perceived mouth health. There are numerous limitations and inherent difficulties in studies involving persons with dementia, and overcoming these in the future will likely require long-term, interdisciplinary approaches.

Factors influencing nurses' aides' provision of oral care for nursing facility residents.

Nurses' aides provide the majority of direct care for nursing facility residents. This study investigated aides' self-reported oral care activities and personal, job, organizational, and resident factors associated with oral care. A 30-item questionnaire was completed by 488 aides, and interviews were conducted with 65 of these aides. Aides were performing oral care activities for residents. Associations between some of the four groups of factors proposed and aides' oral care provision were found. Aides' attitudes toward oral care, lack of time and staff to complete oral care, and behavioral and physical difficulties with residents may have affected the time spent by these aides in providing oral care. The study highlighted the need for further investigation and assessment of (1) aides' CNA training courses and (2) continuing oral health educational interventions in nursing facilities. Personal interview were found to be a useful qualitative instrument for conducting dental research in nursing facilities. Further investigation is needed of interviews and other methodologies, such as observation, to supplement self-report as a measure of aides' oral care activities.